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Dissertations / Theses on the topic 'Colour Enhancement'
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McGinn, Daniel John. "Image restoration and analysis of colour surfaces using the #phi#-#theta# space." Thesis, University of Warwick, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340120.
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Gatti, Pruthvi Venkatesh, and Krishna Teja Velugubantla. "Contrast Enhancement of Colour Images using Transform Based Gamma Correction and Histogram Equalization." Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-14424.
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Contrast is an important factor in any subjective evaluation of image quality. It is the difference in visual properties that makes an object distinguishable from other objects and background. Contrast Enhancement method is mainly used to enhance the contrast in the image by using its Histogram. Histogram is a distribution of numerical data in an image using graphical representation. Histogram Equalization is widely used in image processing to adjust the contrast in the image using histograms. Whereas Gamma Correction is often used to adjust luminance in an image. By combining Histogram Equalization and Gamma Correction we proposed a hybrid method, that is used to modify the histograms and enhance contrast of an image in a digital method. Our proposed method deals with the variants of histogram equalization and transformed based gamma correction. Our method is an automatically transformation technique that improves the contrast of dimmed images via the gamma correction and probability distribution of luminance pixels. The proposed method is converted into an android application. We succeeded in enhancing the contrast of an image by using our method and we have tested for different alpha values. Graphs of the gamma for different alpha values are plotted.
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Charles, Derek Robin. "Algorithmic and learning based filtering techniques with application to colour image noise supression and enhancement." Thesis, Royal Holloway, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406525.
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Lluis-Gomez, Alexis L. "Algorithms for the enhancement of dynamic range and colour constancy of digital images & video." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/19580.
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One of the main objectives in digital imaging is to mimic the capabilities of the human eye, and perhaps, go beyond in certain aspects. However, the human visual system is so versatile, complex, and only partially understood that no up-to-date imaging technology has been able to accurately reproduce the capabilities of the it. The extraordinary capabilities of the human eye have become a crucial shortcoming in digital imaging, since digital photography, video recording, and computer vision applications have continued to demand more realistic and accurate imaging reproduction and analytic capabilities. Over decades, researchers have tried to solve the colour constancy problem, as well as extending the dynamic range of digital imaging devices by proposing a number of algorithms and instrumentation approaches. Nevertheless, no unique solution has been identified; this is partially due to the wide range of computer vision applications that require colour constancy and high dynamic range imaging, and the complexity of the human visual system to achieve effective colour constancy and dynamic range capabilities. The aim of the research presented in this thesis is to enhance the overall image quality within an image signal processor of digital cameras by achieving colour constancy and extending dynamic range capabilities. This is achieved by developing a set of advanced image-processing algorithms that are robust to a number of practical challenges and feasible to be implemented within an image signal processor used in consumer electronics imaging devises. The experiments conducted in this research show that the proposed algorithms supersede state-of-the-art methods in the fields of dynamic range and colour constancy. Moreover, this unique set of image processing algorithms show that if they are used within an image signal processor, they enable digital camera devices to mimic the human visual system s dynamic range and colour constancy capabilities; the ultimate goal of any state-of-the-art technique, or commercial imaging device.
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Bosani, M. A. "DISPLASIA E CANCRO IN PAZIENTI CON RETTOCOLITE ULCEROSA DI LUNGA DURATA: COLONSCOPIA TRADIZIONALE VS PANCROMOENDOSCOPIA VS FUJINON INTELLIGENT COLOUR ENHANCEMENT (FICE). STUDIO PROSPETTICO RANDOMIZZATO." Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/169148.
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Background
Patients with long standing ulcerative colitis have increased risk of colorectal cancer. Current screening endoscopy protocols based on white light endoscopy (WLE) and random biopsies are laborious and of uncertain sensitivity. Novel endoscopic techniques include chromoendoscopy ( CE) and virtal chromoendocopy (FICE) with targeted biopsies.
Aim
The aim was to compare WLE with random biopsies , CE and FICE with targeted biopsies for the detection of suspicious lesions and dysplasia during surveillance colonoscopy in long standing ulcerative colitis patients.
Methods
In this study 158 patients were prospectively randomized and examinated by WLE with random biopsies ( n 78 ), by CE (n 41) and by FICE (n 39) with targeted biopsies. We compared the number of suspicious lesions detected per patient in every group and histopathology of all detected lesions was confirmed by evaluation of biopsy specimens.
Results
In the WLE group we detected suspicious lesions in 17 patients ( 22%), in 30 patients (73%) in the CE group and in 21 patients(54%) in FICE group (p<0,0001). More suspicious mucosal areas per patient was detected by CE and FICE (51 and 28 %) vs WLE (4%); no significative difference was observed in detection of DALM/polyps or neoplasia ( 1 patient in WLE group). Histopathology evaluation of biopsy specimens detected dysplasia o neoplasia in 11 patients of WLE group (14%), in 10 patients of CE group (24%), in 7 patients in FICE group (18%), with no significant difference in the 3 groups but comparable with WLE with fewer biopsies.
Conclusions
The use of CE and FICE improved significantly the number of suspicious lesions detected during surveillance colonoscopy in long standing ulcerative colitis patients, almost for suspicious mucosal areas. The detection of dysplasia with CE and FICE was comparable to WLE with fewer biopsies taken.
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McDonnell, William Francis. "DIGITAL ENHANCEMENT OF COLOR IMAGERY." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275337.
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Thomas, Bruce Allen. "New aspects of digital color image enhancement." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/289128.
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The spatial and chromatic dimensions of digital color image information exhibit unique interrelationships that invite new, color-image-specific, processing strategies. A quantitative exploration of these interrelationships is performed. The resulting data reveals key traits that lead to two new methods of color image enhancement. The first is a method of color image contrast enhancement that exploits the existence of high-pass spatial energy in certain chromatic color components. We present a new, spatially adaptive approach that acknowledges the spatially varying nature of cross-component correspondences. This new approach is suitable for use in any color space. The second is a method of color image denoising that exploits the unique correspondences of polychromatic multiscale edges at fine scales of analysis. The multiscale edges are derived using wavelet methods. This approach preserves image details and noticeably outperforms wavelet thresholding methods of denoising in images containing natural foliage.
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de, Silva Manawaduge Supun Samudika. "An Approach to Utilize a No-Reference Image Quality Metric and Fusion Technique for the Enhancement of Color Images." University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1470049079.
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Mlsna, Phillip Anthony 1956. "Color image enhancement by three-dimensional histogram modification." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278247.
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Histogram-based color image enhancement is usually accomplished by transforming from RGB coordinates to another coordinate system, modifying the components represented in that system, and converting the results back to RGB. Although a few methods function directly in RGB space, they also attempt to reduce dimensonality from the histogram's original three dimensions. Such methods seldom yield images that use the full extent of RGB color range. A new method called "histogram explosion" has been developed to perform true multivariate enhancement directly in RGB color space. Discussed are the algorithm's operational parameters, behavior, implementation, and possible improvements. Results show histogram explosion to be very effective and flexible in enhancing color images. Finally, two iterative methods are suggested as possible approaches for the extension of the histogram equalization algorithm to operate upon three dimensional histograms.
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Hague, George Eric. "Color image enhancement using both chromatic and luminance components." Master's thesis, University of Central Florida, 1994. http://digital.library.ucf.edu/cdm/ref/collection/RTD/id/20326.
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University of Central Florida College of Engineering Thesis<br>A vast amount of work has been published regarding grayscale processing of digital images. Although some of this work has been adapted for color images, many of the resulting algorithms neglect the correlation that exists between the individual RGB color components. Consequently, they introduce color artifacts. Attempts have been amde to decouple the RGB components through color space transformations that isolate the luminance from the chromatic information. Color image enhancement is then considered a two step process, where the luminance and the chromatic components are processed independently. However, the RGB color space only has a finite numer of available colors, which limits the attainable chromatic values for any given luminance level. This recoupling of the chromatic and luminance components constrains the independent processing of these two components. This thesis investigates this coupling and how it effects a number of color image processing algorithms. Specifically, new algorithms for color histogram equalization, automatic white balance and color filtering are presented using the C-Y (color difference) color model. Coupling the chromatic components to the luminance produces improved white balanced results and enhances the ability of histogram equalization to increase saturation contrast. Furthermore, several adaptive filters are implemented using the C-Y color space. Because this color model closely matches the human concept of color, the noise is filtered from color components that closely match the perceptually significant quantities. This improves the results for these adaptive filters, but also requires special attention when filtering the hue component. Improper filtering of the hue component can often lead to color artifacts.<br>M.S.;<br>Electrical and Computer Engineering<br>Engineering;<br>Computer Engineering<br>182 p.<br>viii, 182 leaves, bound : ill. ; 28 cm.
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KIM, CHEOL-SUNG. "DIGITAL COLOR IMAGE ENHANCEMENT BASED ON LUMINANCE & SATURATION." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184228.
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This dissertation analyzes the different characteristics of color images compared to monochromatic images, combines these characteristics with monochromatic image enhancement techniques, and proposes useful color image enhancement algorithms. Luminance, hue, and saturation (L-H-S) color space is selected for color image enhancement. Color luminance is shown to play the most important role in achieving good image enhancement. Color saturation also exhibits unique features which contribute to the enhancement of high frequency details and color contrast. The local windowing method, one of the most popular image processing techniques, is rigorously analyzed for the effects of window size or weighting values on the visual appearance of an image, and the subjective enhancement afforded by local image processing techniques is explained in terms of the human vision system response. The digital color image enhancement algorithms proposed are based on the observation that the enhanced luminance image results in a good color image in L-H-S color space when the chromatic components (hue, and saturation) are kept the same. The saturation component usually contains high frequency details that are not present in the luminance component. However, processing only the saturation, while keeping the luminance and the hue unchanged, is not satisfactory because the response of human vision system presents a low pass filter to the chromatic components. To exploit high frequency details of the saturation component, we take the high frequency component of the inverse saturation image, which correlates with the luminance image, and process the luminance image proportionally to this inverse saturation image. These proposed algorithms are simple to implement. The main three application areas in image enhancement: contrast enhancement, sharpness enhancement, and noise smoothing, are discussed separately. The computer processing algorithms are restricted to those which preserve the natural appearance of the scene.
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Reddy, Manoj Kumar M. "A new adaptive edge enhancement algorithm for color laser printers /." Online version of thesis, 2007. http://hdl.handle.net/1850/5535.
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Tian, Qi-Chong. "Color Correction and Contrast Enhancement for Natural Images and Videos." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLED020/document.
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L'amélioration d'image est une sorte de technique pour améliorer la qualité visuelle d'image, qui joue un rôle très important dans les domaines du traitement d'image et de la vision d'ordinateur. En particulier, nous considérons la correction de couleur et l'amélioration de contraste pour améliorer la qualité d'image.Dans la première partie de cette thèse, nous nous concentrons sur la correction des couleurs pour les images naturelles. Tout d'abord, nous donnons un examen simple de la correction des couleurs. Deuxièmement, nous proposons une méthode efficace de correction des couleurs pour la couture d'images via la spécification d'histogramme et la cartographie globale. Troisièmement, nous présentons une approche de cohérence des couleurs pour les collections d'images, basée sur la spécification de la gamme conservation histogramme.Dans la deuxième partie, nous prêtons attention à l'amélioration du contraste pour les images et les vidéos naturelles. Tout d'abord, nous donnons un simple examen de l'amélioration du contraste. Deuxièmement, nous proposons une méthode de préservation du contraste global de naturalité, qui peut éviter une survalorisation. Troisièmement, nous présentons une méthode de fusion à base de variation pour l'amélioration de l'image d'illumination non uniforme, qui peut éviter la sur-amplification ou la sous-amélioration. Enfin, nous étendons le cadre basé sur la fusion pour améliorer les vidéos avec une stratégie temporellement cohérente, qui n'entraîne pas de scintillement des artefacts<br>Image enhancement is a kind of technique to improve the image visual quality, which plays a very important role in the domains of image processing and computer vision. Specifically, we consider color correction and contrast enhancement to improve the image quality.In the first part of this thesis, we focus on color correction for natural images. Firstly, we give a simple review of color correction. Secondly, we propose an efficient color correction method for image stitching via histogram specification and global mapping. Thirdly, we present a color consistency approach for image collections, based on range preserving histogram specification.In the second part, we pay attention to contrast enhancement for natural images and videos. Firstly, we give a simple review of contrast enhancement. Secondly, we propose a naturalness preservation global contrast enhancement method, which can avoid over-enhancement. Thirdly, we present a variational-based fusion method for non-uniform illumination image enhancement, which can avoid overenhancement or under-enhancement. Finally, we extend the fusion-based framework to enhance videos with a temporally consistent strategy, which does not result in flickering artifacts
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Machado, Gustavo Mello. "A model for simulation of color vision deficiency and a color contrast enhancement technique for dichromats." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/26950.
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As Deficiências na Percepção de Cores (DPC) afetam aproximadamente 200 milhões de pessoas em todo o mundo, comprometendo suas habilidades para efetivamente realizar tarefas relacionadas com cores e com visualização. Isto impacta significantemente os âmbitos pessoais e profissionais de suas vidas. Este trabalho apresenta um modelo baseado na fisiologia para simulação da percepção de cores. Além de modelar visão de cores normal, ele também compreende os tipos mais predominantes de deficiências na visão de cores (i.e., protanopia, deuteranopia, protanomalia e deuteranomalia), cujas causas são hereditárias. Juntos estes representam aproximadamente 99.96% de todos os casos de DPC. Para modelar a percepção de cores da visão humana, este modelo é baseado na teoria dos estágios e é derivado de dados reportados em estudos eletrofisiológicos. Ele é o primeiro modelo a consistentemente tratar visão de cores normal, tricromacia anômala e dicromacia de modo unificados. Seus resultados foram validados por avaliações experimentais envolvendo grupos de indivíduos com deficiência na percepção de cores e outros com visão de cores normal. Além disso, ele pode proporcionar a melhor compreensão e um feedback sobre como aperfeiçoar as experiências de visualização por indivíduos com DPC. Ele também proporciona um framework para se testar hipóteses sobre alguns aspectos acerca das células fotoreceptoras na retina de indivíduos com deficiência na percepção de cores. Este trabalho também apresenta uma técnica automática de recoloração de imagens que visa realçar o contraste de cores para indivíduos dicromatas com custo computacional variando linearmente com o número de pixels. O algoritmo proposto pode ser eficientemente implementado em GPUs, e para imagens com tamanhos tipicos ele apresenta performance de até duas ordens de magnitude mais rápida do que as técnicas estado da arte atuais. Ao contrário das abordagens anteriores, a técnica proposta preserva coerência temporal e, portanto, é adequado para recoloração de vídeos. Este trabalho demonstra a efetividade da técnica proposta ao integrá-la a um sistema de visualização e apresentando, pela primeira vez, cenas de visualização recoloridas para dicromatas em tempo-real e com alta qualidade.<br>Color vision deficiency (CVD) affects approximately 200 million people worldwide, compromising the ability of these individuals to effectively perform color and visualizationrelated tasks. This has a significant impact on their private and professional lives. This thesis presents a physiologically-based model for simulating color perception. Besides modeling normal color vision, it also accounts for the hereditary and most prevalent cases of color vision deficiency (i.e., protanopia, deuteranopia, protanomaly, and deuteranomaly), which together account for approximately 99.96% of all CVD cases. This model is based on the stage theory of human color vision and is derived from data reported in electrophysiological studies. It is the first model to consistently handle normal color vision, anomalous trichromacy, and dichromacy in a unified way. The proposed model was validated through an experimental evaluation involving groups of color vision deficient individuals and normal color vision ones. This model can provide insights and feedback on how to improve visualization experiences for individuals with CVD. It also provides a framework for testing hypotheses about some aspects of the retinal photoreceptors in color vision deficient individuals. This thesis also presents an automatic image-recoloring technique for enhancing color contrast for dichromats whose computational cost varies linearly with the number of input pixels. This approach can be efficiently implemented on GPUs, and for typical image sizes it is up to two orders of magnitude faster than the current state-of-the-art technique. Unlike previous approaches, the proposed technique preserves temporal coherence and, therefore, is suitable for video recoloring. This thesis demonstrates the effectiveness of the proposed technique by integrating it into a visualization system and showing, for the first time, real-time high-quality recolored visualizations for dichromats.
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Erbay, Fulya. "A Comparative Evaluation Of Super." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613253/index.pdf.
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In this thesis, it is proposed to get the high definition color images by using super &ndash<br>resolution algorithms. Resolution enhancement of RGB, HSV and YIQ color domain images is presented. In this study, three solution methods are presented to improve the resolution of HSV color domain images. These solution methods are suggested to beat the color artifacts on super resolution image and decrease the computational complexity in HSV domain applications. PSNR values are measured and compared with the results of other two color domain experiments. In RGB color space, super &ndash<br>resolution algorithms are applied three color channels (R, G, B) separately and PSNR values are measured. In YIQ color domain, only Y channel is processed with super resolution algorithms because Y channel is luminance component of the image and it is the most important channel to improve the resolution of the image in YIQ color domain. Also, the third solution method suggested for HSV color domain offers applying super resolution algorithm to only value channel. Hence, value channel carry brightness data of the image. The results are compared with the YIQ color domain experiments. During the experiments, four different super resolution algorithms are used that are Direct Addition, MAP, POCS and IBP. Although, these methods are widely used reconstruction of monochrome images, here they are used for resolution enhancement of color images. Color super resolution performances of these algorithms are tested.
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Hsiao, Hui-Chun. "ANTHOCYANIN COLOR ENHANCEMENT BY USING CATECHIN AS COPIGMENTS AND STABILITY DURING STORAGE." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397748937.
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Kim, Jongmyon. "Architectural Enhancements for Color Image and Video Processing on Embedded Systems." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6948.
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As emerging portable multimedia applications demand more and more computational throughput with limited energy consumption, the need for high-efficiency, high-throughput embedded processing is becoming an important challenge in computer architecture.
In this regard, this dissertation addresses application-, architecture-, and technology-level issues in existing processing systems to provide efficient processing of multimedia in many, or ideally all, of its form. In particular, this dissertation explores color imaging in multimedia while focusing on two architectural enhancements for memory- and performance-hungry embedded applications: (1) a pixel-truncation technique and (2) a color-aware instruction set (CAX) for embedded multimedia systems. The pixel-truncation technique differs from previous techniques (e.g., 4:2:2 and 4:2:0 subsampling) used in image and video compression applications (e.g., JPEG and MPEG) in that it reduces the information content in individual pixel word sizes rather than in each dimension. Thus, this technique drastically reduces the bandwidth and memory required to transport and store color images without perceivable distortion in color. At the same time, it maintains the pixel storage format of color image processing in which each pixel computation is performed simultaneously on 3-D YCbCr components, which are widely used in the image and video processing community. CAX supports parallel operations on two-packed 16-bit (6:5:5) YCbCr data in a 32-bit datapath processor, providing greater concurrency and efficiency for processing color image sequences.
This dissertation presents the impact of CAX on processing performance and on both area and energy efficiency for color imaging applications in three major processor architectures: dynamically scheduled (superscalar), statically scheduled (very long instruction word, VLIW), and embedded single instruction multiple data (SIMD) array processors. Unlike typical multimedia extensions, CAX obtains substantial performance and code density improvements through direct support for color data processing rather than depending solely on generic subword parallelism. In addition, the ability to reduce data format size reduces system cost. The reduction in data bandwidth also simplifies system design.
In summary, CAX, coupled with the pixel-truncation technique, provides an efficient mechanism that meets the computational requirements and cost goals for future embedded multimedia products.
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Pekkucuksen, Ibrahim Ethem. "Edge directed resolution enhancement and demosaicing." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42734.
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The objective of the proposed research is to develop high performance, low computational complexity resolution enhancement and demosaicing algorithms. Our approach to both problems is to find creative ways to incorporate edge information into the algorithm design. However, in contrast with the usual edge directed approaches, we do not try to detect edge presence and orientation explicitly. For the image interpolation problem, we study the relationship between low resolution and high resolution pixels, and derive a general interpolation formula to be used on all pixels. This simple interpolation algorithm is able to generate sharp edges in any orientation. We also propose a simple 3 by 3 filter that quantifies local luminance transition and apply it to the demosaicing problem. Additionally, we propose a gradient based directional demosaicing method that does not require setting any thresholds. We show that the performance of this algorithm can be improved by using multiscale gradients. Finally, we address the low spectral correlation demosaicing problem by proposing a new family of hybrid color filter array (CFA) patterns and a local algorithm that is two orders of magnitude faster than a comparable non-local solution while offering the same level of performance.
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Mlsna, Phillip Anthony. "Color sets with morphological and B-spline enhancements for content-based image retrieval." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280430.
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Databases of color images have become increasingly important in recent years. The text-based retrieval of images in such databases is practical only if descriptive text annotations accompany each image. Creating such text descriptions is a labor intensive process requiring human interpretation of each image. Except for relatively small, static collections of images, the cost of generating text annotations is prohibitive. The desire to avoid the use of text-based image descriptors has therefore led to the investigation of feature-based descriptors that can automatically be extracted from images and indexed in the database. The definitions of these features and the algorithms for their automated extraction from a given image are the foci of most of the current research into Content-Based Image Retrieval (CBIR). This work focuses on improving the computational efficiency of the well-known color set algorithm for content-based image retrieval. The color set concept is a useful and efficient approach to image indexing and query in a way that combines color and spatial information. By indexing relatively important regions based on both their color content and their spatial locations, the color set method allows rapid retrieval of images matching a specified color-spatial query. Several refinements of the color set approach are presented in this dissertation. First, the process of determining the relevant color combinations for color sets to be indexed has been made approximately one to two orders of magnitude more efficient than the original algorithm. Second, a B-spline descriptor of region shape, size, and position has been incorporated to supplement the original method's rectangular bounding box. Describing contours as closed B-spline curves provides an accurate and storage-efficient means of indexing region location and shape. During image query, the convex hull property of B-spline curves is exploited to enable efficient determination of region containment of a specific point. Finally, an idea for improving the computational efficiency of approximating region contours with periodic, quadratic B-spline curves is briefly discussed.
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PLUTINO, ALICE. "NOVEL APPROACHES IN COLOR ASSESSMENT: FROM POINT-WISE COLORIMETRY TO FILM RESTORATION." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/816787.
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Colorimetry is the science which studies the quantification, reproduction and management of color from its optical, chemical, physical, but also physiological and perceptual point of view. Today, colorimetry has been standardized and color management can count on a robust workflow in point-wise conditions, thus when a color stimulus is considered under specific constraints (e.g., standard illumination and observation). As a consequence, the rigorous application of standard colorimetry is insufficient to reproduce and manage color in real conditions with non-uniform illumination and with complex spatial arrangements. This work of research is organized into three threads of work, which follow the standard pipeline of color signal evaluation: color assessment, color acquisition and processing, and quality assessment.
In the first Part of this study, the assumptions and constraints of standard colorimetry are recalled, together with specific comments on their limits in non-standard and practical applications. The open problems and misuses of colorimetry discussed from the theoretical point of view are supported by preliminary tests and experiments, aiming at highlighting the limits of the application of standard colorimetry in cultural heritage field.
In the second Part of this work, the standard digitization workflow is analyzed, and the issues and effects which could affect the acquisition of contrast and tones in imaging systems are discussed. In particular, the limits of hyperspectral imaging have been tested and examined, in order to assess the main source of noise in the acquisition and to evaluate the reliability of the acquired data. Subsequently, an implementation of the digitization protocol for film restoration is proposed and different methods to perform image enhancement and processing have been examined. For this aim, the family of Spatial Color Algorithms (SCAs), derived from Retinex, has been found successful for cultural heritage applications and a novel approach to film restoration is proposed. This specific family of algorithms, enhance colors according to the spatial distribution of pixel values in the scene, thus include the visual spatial mechanisms in color computation, overcoming the main constraints of standard colorimetry. Nevertheless, SCAs present high computational costs. To address this problem, in this Thesis a new speed-up algorithm is presented in order to allow the enhancement of video streams.
Regarding quality assessment thread, an overview of image quality metrics is presented, and different metrics and measures have been examined and tested, to define which metrics could be the most effective and usable for cultural heritage applications. In this context, a new framework of image quality measures has been presented and applied on historical images and videos.
The field of cultural heritage has been particularly suitable to underline the limits in the application of standard colorimetry, because, in this context, color is never observed as isolated phenomenon, but always inside a spatial arrangement. In this work, film digital restoration has been the main field of application and different approaches and alternative methods have been proposed to overcome the limits of standard color analysis. Anyway, the highlighted limits and solutions are applicable to film restoration, as well as to many other fields, where color sensation cannot be limited to point-wise colorimetry.
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Kim, Yuan Hwan. "Lactate dehydrogenase regulation of the metmyoglobin reducing system to improve color stability of bovine muscles through lactate enhancement." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2966.
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Grobbel, Jeannine Patricia. "Effects of packaging atmospheres and injection enhancement on beef postmortem proteolysis, instrumental tenderness, sensory traits, and display color." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/361.
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SINGH, ISHA. "SOME STUDIES ON IMAGE ENHANCEMENT AND FILTERING." Thesis, DELHI TECHNOLOGICAL UNIVERSITY, 2020. http://dspace.dtu.ac.in:8080/jspui/handle/repository/18449.
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Images are one of the best sources for research & communication. Proper analysis of image data is essential for various fields like satellite images & remote sensing, Biometrics, Criminology, military surveillance, astrology & many more. Requirements of the users vary according to the nature of application in use.Image processing plays a critical role in the analysis of data and is an integral part for various applications.
Image denoising is one of the challenging branches of image processing. Impulse noise is among the prevalent noises that degrade the image quality and its subsequent noise suppression plays a pivotal role in the enhancement of images. The presence of impulse noise cannot be averted during the digitization, acquisition, and transmission of images. Many state of art filters are available in the literature to deal with impulse noise encountered in images. Filters having dual modes of detection and restoration exhibit superior performance in removing noise and thereby keeping the original information of the images intact. In real world sometimes the user is uncertain about his requirements therefore the characteristics of the employed filter for impulse noise removal should be adaptable to the indecisive features of an image.The denoising filter should be robust enough to handle the varying amounts of noise density and should be intuitive in nature.
This thesis work tries to cater to all the essential features required for an efficient filter. Incorporation of fuzzy logic makes the filter more versatile.Investigations performed in this thesis show that the proposed work excels in the quantitative as well as qualitative manner. Four schemes introduced in this thesis are :
(i) High-density impulse noise detection using FCM algorithm (HDIND)
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(ii) Edge preserving fuzzy filter for the suppression of impulse noise in images (EFFSIN)
(iii) Heuristic analysis of neighboring pixels for impulse noise detection (SPHN)
(iv) Impulse noise removal in color image sequences using Fuzzy logic (INFL)
The initial three schemes namely HDIND, EFFSIN, and SPHN focus on the grayscale images and INFL is proposed for color image sequences. All the schemes incorporate an efficient detection criterion and after proper classification of noisy and noise-free pixels, performs the restoration procedure. The use of fuzzy logic in the methods has enhanced the decision making aspect of the algorithms to classify the noisy pixels present in an image. The simulation results are done in isolation for all the schemes deduce that HDIND and EFFSIN are robust in nature and their performance does not deteriorates with a rise in noise density. The edge-preserving nature of EFFSIN preserves the original image data and false alarm rates are reduced. SPHN provides good PSNR and MSE results. INFL is a Spatio-temporal filter that gives excellent performance. SSIM, PSNR, MSE, False alarm and Miss detection rates are used as quality measures to analyze the proposed mechanisms.
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MACIEL, WALTHER ALEXANDRE GIGLIO LOURENCO. "A STUDY ABOUT THE ENHANCEMENT OF FAULT ATTRIBUTES IN SEISMIC DATA BASED ON ANT COLONY MODELS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=23544@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO<br>BOLSA NOTA 10<br>A interpretação de falhas sísmicas é uma tarefa complexa e trabalhosa, que está sujeita à experiência do geólogo. Normalmente ela é auxiliada pela análise de atributos sísmicos, que podem não ser suficientes para uma clara visualização das falhas. Este trabalho realiza uma análise dos métodos atuais que utilizam ACO para o realce de atributos de falha, de forma a entender a contribuição de cada etapa para o resultado. Com base nessa análise, um novo método é proposto, o qual elimina as fraquezas encontradas de forma a buscar uma convergência mais estável e rápida ao resultado.<br>The interpretation of seismic faults is a complex and labourious task, which is dependent on the experience of the geologist. The interpretation is normally aided by seismic attributes. However, they may not be enough for a clear visualization nor to be used in automatic extraction methods. This dissertation accomplishes an examination of the state of the art ACO algorithms for fault enhancement. This study reveals the importance, contributions and weaknesses of each step of these methods. From there, a new method is proposed, which eliminates some of the problems found, acquiring a more stable and quick convergence of the end result.
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Alrowili, Mohammed F. H. "Capacity Enhancement Approaches for Long Term Evolution networks: Capacity Enhancement-Inspired Self-Organized Networking to Enhance Capacity and Fairness of Traffic in Long Term Evolution Networks by Utilising Dynamic Mobile Base-Stations." Thesis, University of Bradford, 2018. http://hdl.handle.net/10454/17322.
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The long-term evolution (LTE) network has been proposed to provide better network capacity than the earlier 3G network. Driven by the market, the conventional LTE (3G) network standard could not achieve the expectations of the international mobile telecommunications advanced (IMT-Advanced) standard. To satisfy this gap, the LTE-Advanced was introduced with additional network functionalities to meet up with the IMT-Advanced Standard. In addition, due to the need to minimize operational expenditure (OPEX) and reduce human interventions, the wireless cellular networks are required to be self-aware, self-reconfigurable, self-adaptive and smart. An example of such network involves transceiver base stations (BTSs) within a self-organizing network (SON).
Besides these great breakthroughs, the conventional LTE and LTE-Advanced networks have not been designed with the intelligence of scalable capacity output especially in sudden demographic changes, namely during events of football, malls, worship centres or during religious and cultural festivals. Since most of these events cannot be predicted, modern cellular networks must be scalable in terms of capacity and coverage in such unpredictable demographic surge. Thus, the use of dynamic BTSs is proposed to be used in modern and future cellular networks for crowd and demographic change managements.
Dynamic BTSs are complements of the capability of SONs to search, determine and deploy less crowded/idle BTSs to densely crowded cells for scalable capacity management. The mobile BTSs will discover areas of dark coverages and fill-up the gap in terms of providing cellular services. The proposed network relieves the LTE network from overloading thus reducing packet loss, delay and improves fair load sharing.
In order to trail the best (least) path, a bio-inspired optimization algorithm based on swarm-particle optimization is proposed over the dynamic BTS network. It uses the ant-colony optimization algorithm (ACOA) to find the least path. A comparison between an optimized path and the un-optimized path showed huge gain in terms of delay, fair load sharing and the percentage of packet loss.
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Enokihara, Cyro Teiti. "Estudo do quartzo verde de origem hidrotermal tratado com radiação Gama." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-18022014-133514/.
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Uma variedade específica de quartzo de cor verde, seja natural ou induzida pela radiação é muito rara. Trata-se de um mecanismo de formação de cor completamente diferente daqueles conhecidos e amplamente discutidos na literatura, que são responsáveis pela formação do quartzo fumê, do citrino e da ametista, incluindo a prasiolita produzida pelo aquecimento da ametista de Montezuma (MG). Somente duas ocorrências, conhecidas até o momento, tem o quartzo incolor, uma no pequeno distrito em Thunder Bay Amethist Mine, no Canadá e a outra na Bacia do Paraná ( Brasil) , ao longo de uma faixa de 600 km, com ocorrências dispersas de geodos, que se estende da região de Quaraí (RS) até a localidade de Uberlândia (MG). Estas duas ocorrências foram formadas sob fortes atividades hidrotermais, a de Thunder Bay é devido ao tectonismo e a da Bacia do Paraná está relacionada às atividades da água meteórica e hidrotermal do Aquífero Guarani. Estes cristais de quartzo hidrotermal apresentam um histórico de crescimento muito rápido, permitindo a formação dos defeitos de crescimento como as geminações, o crescimento em mosaico, as formações com pequenos ângulos inclinados e as estrias que facilitam a absorção da água na forma de água molecular, silanol (Si-OH), hidroxila (OH) e como micro inclusões. Este tipo de quartzo pode ser considerado como quartzo hidratado (wet quartz) semelhante ao quartzo sintético. O teor em água, com até 3200 ppm em massa, é superior à concentração das impurezas estruturais como o Fe, Al e Li. Não existe uma correlação entre o conteúdo da água e a quantidade de impurezas, como ocorre em outras variedades de cor do quartzo. No quartzo hidrotermal de geodos são formados complexos de silanol que quando são irradiados geram os centros de cor NBOHC (Centro de cor do oxigênio com elétron desemparelhado que não participa da ligação) que apresenta absorção no intervalo de 590 nm a 620 nm e formando uma janela de transmissão a 550 nm aproximadamente, responsável pela cor verde. Várias técnicas de análises químicas e de espectroscopia foram empregadas para caracterizar estas amostras de quartzo verde. A determinação do teor de água por meio dos espectros de infravermelho FTIR mostraram menos água (até 2300 ppm em massa), em comparação com os resultados das análises de aquecimento (3200 ppm) decorrente provavelmente, ao complexo silanol remanescente. Para documentar a influência da água na formação da cor verde foram realizadas análises por espectroscopia de infravermelho FTIR em amostras de quartzo de 3 diferentes grupos de ambientes geológicos, o quartzo pegmatítico com Al e Li formado à alta temperatura da região de Santana do Araguaia, o quartzo de veios hidrotermais com Al, mas sem água originado à média temperatura, da região de Curvelo e a ametista com muito Fe, pouco Al e pouco silanol da região de Brejinho e o quartzo de geodos hidrotermais formado a baixa temperatura com alto conteúdo de água molecular e silanol, e com muito Fe e pouco Al. As análises e as comparações permitiram diferenciar e determinar a formação do centro de cor NBOHC (Centro de cor do oxigênio com elétrons desemparelhados que não participam da ligação) para o quartzo hidrotermal de geodos da Bacia do Paraná. Assim, somente cristais de quartzo com alta concentração de água molecular e silanol são apropriados para desenvolver a cor verde por meio da radiação gama. Pode-se mencionar que no mesmo geodo podem coexistir cristais de quartzo com diferentes teores de água. Cabe ressaltar também que o quartzo verde tratado com radiação gama é sensível à radiação ultravioleta e ao aquecimento, levando à perda parcial ou total da cor verde.<br>A specific variety of quartz showing a green color in nature or induced artificially by radiation is quite rare. This can be explained by the fact that the mechanism of formation of this color is very different from the ones widely discussed in the literature and responsible for the formation of the fumée, citrine and amethyst types of quartz, including the prasiolite (leak green quartz) formed by heating amethyst from Montezuma, Brazil. Only two occurrences are known today, where this type of quartz can be found: Canada, at the Thunder Bay Amethyst Mine, Ontario, a small district, and Brazil, at widely scattered geode occurrences along a 600 km stretch from Quaraí at Brazils southernmost tip to Uberlandia in Minas Gerais. These two occurrences have been formed by strong hydrothermal activities, at Thunder Bay due to tectonics and in Brazil by meteoric and hydrothermal waters of the Guarani aquifer. That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects (twinning, small angle tilting, mosaic growth, striations) and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. This type of quartz can be considered ¨wet quartz¨, similar to synthetic quartz. The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). There is no correlation between water content and cations as in other color varieties. Instead, silanol complexes are formed, which by radiation due to gamma rays form the color center NBOHC (non-bonding oxygen hole defect), showing absorption between 590 to 620 nm and leaving a transmission window at about 550nm, responsible for the green color. To characterize samples which will be colored green by gamma rays analyses by ICP, NAA, Electron microscopy, water loss techniques and UV-VIS and NIR-FTIR spectroscopic have been made. The spectroscopic water determination showed less water (up to 2300 ppm by weight) compared with heating techniques (3200 ppm), probably due to remaining silanol complexes.To trace the influence of water on color formation, samples from 3 different geological settings (high temperature pegmatitic quartz with Al and Li, from Santana de Araguaia; intermediate temperature vein quartz with Al but without water from Curvelo; amethyst with more Fe, less Al and small silanol content from Brejinho, and low temperature regimes from geodes, high silanol and high molecular water, cations similar to the above mentioned) have been analised by NIR spectroscopy.The former will not show green color, only the latter one. It may be mentioned that even in geodes one has crystals with high and intermediate water content coexisting. The crystals with high silanol and molecular water are the ones to treat by radiation. The radiation induced color is heat and UV sensible with bleaching by longer exposure to these factors.
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Pierre, Fabien. "Méthodes variationnelles pour la colorisation d’images, de vidéos, et la correction des couleurs." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0250/document.
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Cette thèse traite de problèmes liés à la couleur. En particulier, on s’intéresse à des problématiques communes à la colorisation d’images, de vidéos et au rehaussement de contraste. Si on considère qu’une image est composée de deux informations complémentaires, une achromatique (sans couleur) et l’autre chromatique (en couleur), les applications étudiées consistent à traiter une de ces deux informations en préservant sa complémentaire. En colorisation, la difficulté est de calculer une image couleur en imposant son niveau de gris. Le rehaussement de contraste vise à modifier l’intensité d’une image en préservant sa teinte. Ces problématiques communes nous ont conduits à étudier formellement la géométrie de l’espace RGB. On a démontré que les espaces couleur classiques de la littérature pour résoudre ces types de problème conduisent à des erreurs. Un algorithme, appelé spécification luminance-teinte, qui calcule une couleur ayant une teinte et une luminance données est décrit dans cette thèse. L’extension de cette méthode à un cadre variationnel a été proposée. Ce modèle a été utilisé avec succès pour rehausser les images couleur, en utilisant des hypothèses connues sur le système visuel humain. Les méthodes de l’état-de-l’art pour la colorisation d’images se divisent en deux catégories. La première catégorie regroupe celles qui diffusent des points de couleurs posés par l’utilisateur pour obtenir une image colorisée (colorisation manuelle). La seconde est constituée de celles qui utilisent une image couleur de référence ou une base d’images couleur et transfèrent les couleurs de la référence sur l’image en niveaux de gris (colorisation basée exemple). Les deux types de méthodes ont leurs avantages et inconvénients. Dans cette thèse, on propose un modèle variationnel pour la colorisation basée exemple. Celui-ci est étendu en une méthode unifiant la colorisation manuelle et basée exemple. Enfin, nous décrivons des modèles variationnels qui colorisent des vidéos tout en permettent une interaction avec l’utilisateur<br>This thesis deals with problems related to color. In particular, we are interested inproblems which arise in image and video colorization and contrast enhancement. When considering color images composed of two complementary information, oneachromatic (without color) and the other chromatic (in color), the applications studied in this thesis are based on the processing one of these information while preserving its complement. In colorization, the challenge is to compute a color image while constraining its gray-scale channel. Contrast enhancement aims to modify the intensity channel of an image while preserving its hue.These joined problems require to formally study the RGB space geometry. In this work, it has been shown that the classical color spaces of the literature designed to solve these classes of problems lead to errors. An novel algorithm, called luminance-hue specification, which computes a color with a given hue and luminance is described in this thesis. The extension of this method to a variational framework has been proposed. This model has been used successfully to enhance color images, using well-known assumptions about the human visual system. The state-of-the-art methods for image colorization fall into two categories. The first category includes those that diffuse color scribbles drawn by the user (manual colorization). The second consists of those that benefits from a reference color image or a base of reference images to transfer the colors from the reference to the grayscale image (exemplar-based colorization). Both approach have their advantages and drawbacks. In this thesis, we design a variational model for exemplar-based colorization which is extended to a method unifying the manual colorization and the exemplar-based one. Finally, we describe two variational models to colorize videos in interaction with the user
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Mao, Fei. "Réalisation des nanostructures désirées en or et en argent par effet thermique local induit optiquement : Application au stockage de données et à l’imprimante couleur." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASN011.
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This work focuses on the investigation of plasmonic Gold (Au) and Silver (Ag) nanoparticles (NPs) by using optically induced local thermal dewetting technique and their applications. Firstly, Au and Ag NPs are fabricated by a thermal annealing method using a hot oven. This technique allows obtaining Au and Ag NPs, which are randomly distributed in a large area. The NPs sizes and properties are controlled by annealing conditions, such as annealing temperature and duration. Plasmonic properties of Au and Ag NPs are experimentally characterized and compared with the simulation ones performed by the FDTD method. These large-area Au and Ag NPs are demonstrated to be useful for applications in fluorescence enhancement and random laser. Secondly, we demonstrate a robust way to realize desired plasmonic nanostructures by using a direct laser writing method. This technique bases on optically induced local thermal effect allowing the realization of NPs at a small area, i.e. focusing area. By moving thus the laser spot, any desired plasmonic structure can be realized. The NPs sizes and distributions can be controlled by exposure doses (laser power and exposure time) and moving trajectory of the focusing spot resulting in different reflection or transmission colors. By focusing a continuous-wave laser at 532 nm on Au films having 50 nm thickness, we demonstrated for the first time the direct fabrication of plasmonic nanoholes array. These fabricated structures are demonstrated to be very potential for many applications such as data storage, color nanoprinter, fluorescence enhancement, and plasmonics based random laser<br>This work focuses on the investigation of plasmonic Gold (Au) and Silver (Ag) nanoparticles (NPs) by using optically induced local thermal dewetting technique and their applications. Firstly, Au and Ag NPs are fabricated by a thermal annealing method using a hot oven. This technique allows obtaining Au and Ag NPs, which are randomly distributed in a large area. The NPs sizes and properties are controlled by annealing conditions, such as annealing temperature and duration. Plasmonic properties of Au and Ag NPs are experimentally characterized and compared with the simulation ones performed by the FDTD method. These large-area Au and Ag NPs are demonstrated to be useful for applications in fluorescence enhancement and random laser. Secondly, we demonstrate a robust way to realize desired plasmonic nanostructures by using a direct laser writing method. This technique bases on optically induced local thermal effect allowing the realization of NPs at a small area, i.e. focusing area. By moving thus the laser spot, any desired plasmonic structure can be realized. The NPs sizes and distributions can be controlled by exposure doses (laser power and exposure time) and moving trajectory of the focusing spot resulting in different reflection or transmission colors. By focusing a continuous-wave laser at 532 nm on Au films having 50 nm thickness, we demonstrated for the first time the direct fabrication of plasmonic nanoholes array. These fabricated structures are demonstrated to be very potential for many applications such as data storage, color nanoprinter, fluorescence enhancement, and plasmonics based random laser
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Yeh, Hsiu-ming, and 葉修銘. "COLOR IMAGE SEGMENTATION BASED ON COLOR ENHANCEMENT AND COLOR QUANTIZATION." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/06079814044429919725.
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碩士<br>大同大學<br>電機工程學系(所)<br>93<br>In order to improve the quality of imagery, digital image enhancement techniques have been developed. In general, the image enhancement is applied in the RGB color space that can be implemented simply and effectively without computationally intensive.
In previous research is to increase the directional resolution using a concept that calls Vector Amplification, increasing the magnitude of color vectors close to the direction of the color of interest (COI) to enhance image. The vector amplification may need more computationally intensive. Furthermore, the image enhancement doesn’t have qualified result in RGB color space.
Due to advantages of color differences in uniform color space such as Lab, Euclidean distance has close correlation with the perceptual color difference in the uniform color space. Therefore, based on the algorithm of Vector Amplification, the image can be enhanced by reducing the Euclidean distance with specified multi-color of interest in uniform color space.
Another interesting issue is how to generate COIs for image segmentation. First, cluster of colors are generated by the color quantization from the original image. Then representational COIs are generated by merging color element of cluster within the region of color difference. Hence, image can be segmented by iterating color enhancement and color quantization in uniform color space without any overflow color information and color distortion.
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Yi-Mei, Chiu. "Color Deficiency Aid Process and Color Image Enhancement." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1507200512131100.
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Chiu, Yi-Mei, and 邱逸玫. "Color Deficiency Aid Process and Color Image Enhancement." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/65278153718249963051.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>93<br>Approximately one man out of twelve has some degree of color deficiency. There is no cure for color vision deficiency. Though there are some techniques trying to help them distinguish color, such as tinted spectacles and monocular contact lenses, however, these devices might boil down to further serious situation, such as impaired visual acuity, visual distortions, and diminishing the depth perception. However, vision is the one that we rely on most to access information. Nowadays, for the development of technology, people acquire quite many facts from multimedia. Hence, color also play a role in conveying information and hence obstruct some color deficient people to some degree. Hence, this thesis offers assistance processes to help color deficient people distinguish colors. This assistance algorithm is based on utilizing the color gamut seen by color deficient people. The effect of the proposed assistance process is proved by examine the enhanced image through the color deficient vision simulation in [4]. Besides, other assistance processes are compared with the proposed one.
In the later of the thesis, we focus on contrast enhancement on ordinary images. We proposed the saturation enhancement methods without hue and luminance changes in CIE xyY and CIE L*u*v*. The main contribution of this part is that we take the dependence of luminance and chromaticity into consideration. Hence, the image artifacts and color distortion, which other saturation enhancement would results in, are not produced through the proposed saturation enhancement. Furthermore, the proposed saturation enhancement methods are quite useful and could be applied to many fields, such as gamut calculation, and clipping after luminance processing. We also proposed a background adjustment approach cooperates with the proposed saturation enhancement methods to virtually restore the ancient Chinese paintings.
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黃和村. "Edge-enhancement Color Interpolation scheme for Color Filter Arrays." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/01145582274623565501.
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碩士<br>長庚大學<br>電機工程研究所<br>90<br>The color interpolation is the process of deciding the unknown values of a cell at the position lying between some pre-known samples in Color Filter Arrays (CFA). In the past, many interpolation methods such as nearest neighbor, linear, bilinear, edge-sensitive, cubic B-spline, effective color signal correlation, and weighting-based effective color signal correlation, etc. has been proposed. However, they are not suitable to the color interpolation for the digital still camera with single charge-couple-device and CFA. The main drawbacks of these interpolation approaches are the color-alias and the blurred-edge effects. Although edge-sensitive, cubic B-spline, effective color signal correlation, and weighting-based effective color signal correlation color interpolations straightened out these problems more or less, they have either high complexity or utilize much of near neighboring signals.
To sharpen the edge and reduce the color—alias, a novel interpolation scheme with the characteristics of edge-sensitive and color filtering is proposed. From the simulation results, it is shown that the proposed scheme not only obtain the same image quality as the methods using effective color signal correlation, and weighting-based effective color signal correlation color interpolations, but also reduce the computational complexity and then achieve the goal of cost-down for practical applications. The computational complexity of the proposed method is acceptable compared with the other color interpolations.
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Huang, Yen-Chao, and 黃彥超. "Image Enhancement and Color Transfer Techniques." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/93686374360834703505.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>101<br>In this thesis, we study two image processing techniques including image enhancement and color transfer. With the development of technology, people can use digital camera or cell phone to capture the photo in daily life. However, the results of these easily captured images are often not as good as expected. In order to make images clear and pleasing, one can use image enhancement techniques to adjust images. Contrast correction and sharpness enhancement are the two common methods of image enhancement. Traditional contrast enhancement is global correction. Global correction provides good results for either overexposed or underexposed images. But it produces disappoint results for images which have both bright region and dark region. Local correction can make both bright region and dark region clearer. To enhance sharpness, traditional unsharp masking uses low pass filter and usual addition and multiplication. However, traditional unsharp masking suffers from halo artifact and out-of-range problem. A general unsharp masking adopts edge preserving filter and generalized addition and multiplication to resolve above problems. After studying kinds of image enhancement techniques, we implement and compare these methods.
In the applications of post-production industry and image composition, the color characteristic should be consistent between two or more images. Color transfer plays an important role in those of applications. Traditional method uses statistical matching to perform color transfer. When two images are too different, this method produces unnatural results. Histogram-based method improves the color similarity between the synthetic image and target image, but it suffers from grain artifact. We analyze and compare the methods as mentioned above, then provide an improvement of color transfer. Furthermore, we apply our color transfer method to perform image re-coloring for colorblindness. Hopefully to make a color-blind can enjoy more beautiful images. Finally, we apply our color transfer method to perform enhancement for underwater images. Ocean engineering researchers can get a clearer underwater image by our method.
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Jen, Tzu-Cheng, and 任慈澄. "Contrast Enhancement, Sharpness Enhancement and Color Temperature Adjustment over LCD Displays." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/53093135097214365215.
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碩士<br>國立交通大學<br>電子工程系所<br>92<br>Nowadays, liquid crystal display (LCD) has become one of the most popular electronic products in consumer electronics. LCD’s have been widely used in mobile phones, personal digital assistants (PDA), and TV’s. Advantages of LCD’s include low power consumption, light weight, lower radiation, and so on. However, due to some physical limitations of liquid crystal, the quality of displayed images on LCD’s is inferior to that on cathode ray tubes (CRT). In this thesis, we aim to construct some image processing techniques for LCD. These techniques include contrast enhancement, sharpness enhancement and color temperature adjustment. About contrast enhancement, the edge information of the image is used and a corresponding expansion force is generated to enhance contrast. For sharpness enhancement, we propose a new approach for enhancement based on some characteristics of human visual perception. For color temperature adjustment, we propose a new approach for color temperature estimation based on gray world assumption.
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Ko, Chia-Chieh, and 柯佳伽. "Color Image Quality Enhancement Using Retinex Algorithm." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/565fvu.
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碩士<br>世新大學<br>資訊管理學研究所(含碩專班)<br>96<br>This study aims the visual image contrast enhancement of the color images. Amongst of them, Retinex is the most significant enhancement for human visual system, taking into account in both color component of the rendering and the image contrast enhanced that makes the choices. Because of the Retinex absence use images histogram information distribution, image histogram distribution in deriving Quartile Sigmoid Function (QSF) is proposed. By combining the QSF mapping and Retinex theory, the resulting has shown well in both the rending and contrast enhancement.
Sets of images to be used for proposed images enhancement model. As for bands of information of Histogram equalization is employed, integration of both MSR and the Retinex with Quartile Sigmoid Function (QSF) demonstrates the effectiveness of the algorithm in terms of the image quality
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Weng, Feng-Shen, and 翁豐盛. "A Real-Time Automatic Color Image Enhancement." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/vmvhg4.
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碩士<br>國立臺灣科技大學<br>電機工程系<br>99<br>In the digital photographing, the quality of the images may be affected due to the lack or the
changes of the ambient light. In the past, many image enhancement schemes for the image
enhancement are proposed. However, those schemes focus on either the brightness or the contrast of
the image. In the thesis, proposed method to be proposed a scheme for automatic image enhancements,
including the contrast enhancement, the brightness enhancement, and the image classification. First, the
image classification categorize input images according to the standard deviation and the average
luminance, and then take the corresponding schemes to enhance the contrast or the brightness of the
images. In the luminance enhancement, the propose method modified the scheme of the color image
enhancement based on the space variant luminance map, which is proposed by Lee et al. In the contrast
enhancement, our propose method modified the scheme based on the weighted histogram equalization,
which is proposed by Yun et al. Proposed method overcome the challenge that the input image is not
easy to enhance when the input image contrast is extreme poor condition. The proposed scheme of
automatic image enhancements is validated by a Borland C++ program. It should be noted that the
quality of images is better than that of the schemes proposed by Yun et al. and Lee et al.
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Ching-Hua, Chang, and 張慶華. "Color Image Interpolation and Contrast Enhancement Techniques." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/64860044896181981407.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>91<br>Color interpolation plays an important role in the image processing of digital still cameras (DSCs). DSCs use a single charge-coupled device (CCD) sensor and a color filter array (CFA) to sample images. At the location of each pixel, only one color sample is caught, and the full-color images should be reconstructed by resorting to CFA interpolation algorithm. On the other hand, image enhancements have been widely applied in multimedia, medical science, and so on. Some of them focus on emphasizing the local intensity or color variations in an image in order to increase the perceptual visibility.
In this thesis, we further discuss blurs and distortions in reconstructed images according to the theory of digital signal processing and the color correlation between channels. Based on a well-performed reconstructed image of green channel, we have efficiently used the information of green channel to compensate the high frequency of red and blue channels. Further, it can also help us extent the filters to cancel the aliases while the green image has less distortion since the color signals are strongly correlated. All of the filters we choose are compose of 1-D high-pass or low-pass filters, and thus, it is easier to optimize that the implementation involves only the use of linear filters.
In the later half of the thesis, we introduce an improved color contrast enhancement. We propose to choose the more uniform coordinates, u′,v′ chromaticity diagram. We adopt the concept of saturation and de-saturation base on the center of gravity law for color mixture in the u′v′ chromaticity domain. The main contribution is that we define a well achromatic region, named ‘achromatic triangle’. It can eliminate the distortions and false colors among images. Hence, it is a suitable algorithm for more general images in color contrast enhancement and better virtual restoration in the Chinese paintings.
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Li, Yun-Ju, and 李昀儒. "Color Image Enhancement Using Hybrid Retinex Algorithm." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/21207789503399867611.
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碩士<br>世新大學<br>圖文傳播暨數位出版學研究所(含碩專班)<br>93<br>An image enhancement model based on the Human Visual System is proposed. Image enhancement processing normally decreases image quality in some aspects, because the representation of color space is not linear.
The Retinex algorithm can be generally used in mamy kinds of images by considering human visual perception. The existing Retinex algorithm both Single-Scale Retinex or Multiple-Scale Retinex, do not take into account the local variations of the contrast within an image scence. Therefore the performance of those models are limited.
A modified Retinex algorithm by using non-isotropic Gaussian kernel filters to fit the human visual system and add the the image quality is proposed.
A number of experiments are conducted to demonstrate the performance of the proposed algorithm.
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Hsieh, Chang-Hsi. "Multiple Color Transfer: Example-Based Photo Enhancement." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2607200710404200.
Full text
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Hsieh, Chang-Hsi, and 謝昌熹. "Multiple Color Transfer: Example-Based Photo Enhancement." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/22239749441668911443.
Full textAbstract:
碩士<br>臺灣大學<br>資訊工程學研究所<br>95<br>One of the most common situations in photo editing is that users want some specific effects but don’t know how to achieve them. Nevertheless, they have an image in their mind about how the photo should be, which is derived from a better photo on similar subjects, or from their imagination. With this user motivation in mind, this thesis proposes a method for altering a photo’s color based on the coloring of another exemplary photo. Users simply set the requirement by drawing some pairs of brush strokes in corresponding regions and then the tool will perform the editing automatically.
The goal of our tool is to enable the photo editor to easily alter the dissatisfied photo by referring the other acceptable photo. A suitable user interface have designed for drawing the corresponding regions between a source and one or more targets to transfer the desired color. Besides, in most general cases, users are just dissatisfied with a part of the photo, so our system allow users to edit their photo completely or partially by the same work flow, and our algorithm can preserve the satisfying or ex-editing region successfully.
In this thesis, we find the region the user expect to edit by a graph cut optimization algorithm, and we have designed a new energy function which can consider the color and positional information simultaneously in this process. Additionally, a multiple color transfer method is developed to estimate the different influence of a set of transfer functions on a pixel and accumulate the influences to alter the pixel. Moreover, a image-guide optimization is used to increase the coherence in regions and eliminate the artifacts near edges in the result.
We also display a variety application of our tool in this thesis, and Our system can produce accurate results that match users’ expectations. More importantly, the tool is very easy to learn; no photography or photo editing knowledge is required, and users don’t need to change their habit of taking photos.
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Su-ShiaWang and 王素霞. "Low-complexity Defogging Algorithm with Color Enhancement." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/86834180314643460233.
Full textAbstract:
碩士<br>國立成功大學<br>資訊工程學系碩博士班<br>100<br>In some computer vision applications, such as monitors and obstacle detection systems, the visibility and color of the scene taken by these devices might be severely degraded due to bad weather conditions such as fog or haze. Therefore, defogging technology has becomes an important issue. Nowadays, there are a lot of papers that discuss how to recover a clear image from a foggy one, but these methods are often so complex that they need much more time to process an image. For this reason, a good image defogging technique that is low-complexity is crucial.
In this paper, we bring up a low-complexity defogging algorithm with color enhancement. There are three main steps to this method. First, we calculate an the value of atmospheric light from the lighter group and the darker group of an input image. Second, we use differential transmission estimation to detect edges and ease the halo effect. Finally, we employ tone mapping and illumination adjustment to optimize restored images. The execution time of our method is faster than other papers. It only takes about 0.2 sec for processing a 600×400 image. Furthermore, we know our resulting images are better in both visibility and color enhancement from comparison.
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Huang, Shan-Shih, and 黃善詩. "Enhancement, Clipping, and Rearrangement of Color Document Images." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/91343735333727174692.
Full textAbstract:
碩士<br>國立交通大學<br>資訊科學學系<br>86<br>In this study, a color document analysis system, including
color picture quality improvement, document understanding, and
article rearrangement isproposed. First, a full color
hierarchical moment preserving technique is proposed to
eliminate distortion caused by printing or scanning.
Importantcolors can be preserved automatically and color
reduction can be achieved.If the number of colors is small, a
modified k-means clustering is proposedto preserve th most
important colors, which is based on the observation
thatimportant colors in common color documents tend to form
clusters. Noise comefrom color reduction can be eliminated be
the region growing method and someoperations of morphology. For
document understanding and article rearrangement,we extract
document blocks by vertical and horizontal projections and
classifyblocks using some features of blocks. And then, global
and local projections are used again to segment the lines and
characters of blocks. Different processes are designed for
segmenting characters in headlines and article contents. In
finding the reading order of blocks, the knowledge of general
layout rules, the composition techniques in Chinese documents,
and the relationship of blocks are utilized. Finally, for the
article rearrangementphase, users can choose serveral formats
designed for manual or automatic rearrangement. Good
experimental results prove the feasibility and practicability of
the proposed approaches.
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Chou, Ching-Yao, and 周敬堯. "Medical Image Enhancement Using Modified Color Histogram Equalization." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/bdpgee.
Full textAbstract:
碩士<br>國立中正大學<br>醫療資訊管理研究所<br>103<br>Image enhancement represents a crucial application in medical imaging. Histogram equalization is one of the image enhancement techniques employed to enhance image contrast, which has become an vital part of general and medical image processing, and has been widely studied and applied. However, traditional histogram equalization achieves poor image enhancement results because it does not consider hue preservation. This study proposes a novel image enhancement method that incorporates hue preservation to address the problem of unpreserved hue in traditional approaches. In addition, this study use the Gabor filter to enhance image details. The results indicated that both methods achieved satisfactory results. Finally, this study proposed methods are applied to retinal and prostate cancer images. This can effectively assist physicians in making professional judgment.
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王維綱. "Color Image Contrast Enhancement Using Image Fusion Technique." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/85252293683372085640.
Full textAbstract:
碩士<br>國立交通大學<br>多媒體工程研究所<br>100<br>There are more and more digital images in our daily life thanks to the popularity of photograph capturing equipments, such as digital cameras and mobile phones. In addition, as the Internet and social networks have been well developed, it’s easier for people to share images with their friends. However, not all people are satisfied with the photos they taken due to the limitations of the image capturing devices. The improper luminance condition may cause under-exposed and over-exposed images. To solve this problem, plenty of researches are proposed for contrast enhancement. However, they often cannot afford to produce pleasing images for a broad variety of low contrast images or cannot be automatically applied on all images. Hence, in this thesis, we propose a classified image fusion (CIF) method for image contrast enhancement. First several virtual images having different intensities are generated. Second, the input image pixels are classified to several classes according to their luminance values. Finally, CIF was proposed to combine these exposure images to produce a fused image in which every region is well-exposed.
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Chen, Jue-lei, and 陳建澧. "Color image enhancement using Bilateral and GDDRC algorithms." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53595834806152629731.
Full textAbstract:
碩士<br>世新大學<br>資訊管理學研究所(含碩專班)<br>98<br>Mainly due to the Bilateral filter itself is the use of dynamic range compression is not in itself the main use of the advantages, so the present study, GDDRC significantly improved the ability to be Bilateral filter of the deficiencies and, through detailed images of the detachable Bilateral filter usefulness, combined with GDDRC to use, the details of the Detachable a more complete image, so that the final result image of the details of the lines can be a complete presentation, so that Bilateral filter and GDDRC algorithms on a combination of a more effective use of its advantages
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楊國昌. "Application of Neural Networks in Image Color Enhancement." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/93726722486366171708.
Full textAbstract:
碩士<br>建國科技大學<br>自動化工程系暨機電光系統研究所<br>104<br>This paper neural network application in image color design, a picture of the major improvements in color RGB primary colors, let the picture image to have a good image quality, the use of the three primary colors to enhance color picture image acuity, but also let the picture clearer. Traditional image found poor quality image processing, are involved RGB color image is caused by the uneven distribution, this article is designed to MATLAB software simulation tools, using competitive neural network for image classification for the study of the RGB color components, and improve the quality of the bad image do RGB color adjustments can be restored to optimize image quality of the video image.
Keywords: Neural network, Competitive neural network, Video image, RGB Trichromatic
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Lee, Chen-Yu, and 李丞祐. "Color Space-based Digital Image Detection and Enhancement." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/47383271046236131192.
Full textAbstract:
碩士<br>國立臺灣大學<br>電信工程學研究所<br>101<br>In the procedure of capturing and processing a photo, there are always a lot of problems in the course. For example, when we want to take a picture for someone, we usually want to focus on the people. Finding the position of the faces in the photo by features such as skin color will play an important role in the procedure. At the time taking a photo in the water, we will find that the ambient light becomes blue instead of white. The intensity of the photos taken in the water will have the highest average value in the blue plate. When we take a picture in the raining or snowing day, the photographs are disturbed by the rain or snow streaks which appear in the range of the scene. It will let the photographs having a lot of steak-shape noise. The methods to solve these kinds of problems will severely affect the time consumption.
We will discuss the methods of skin-color detection, underwater image enhancement and rain/snow removal in single image in this thesis. In the part of skin color detection, we will introduce the methods of detecting the skin color in different color spaces [1]-[6]. Besides, we propose a new method for skin color detection which is based on image normalization. In the part of underwater image enhancement, we introduce two methods to fix the photograph. One of the method is based on the colour model [7] and the other is based on wavelength compensation and dehazing [8]. Besides, we also propose a method based on color transfer [17] and dark channel prior-based [10], [11]. In the part of rain/snow removal in single image, we will introduce the methods based on guided filter [19], [21], [29]. We propose a new method based on frequency analysis [20] and object recognition to solve the problem of rain and snow in the photograph.
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GUPTA, KRITI. "IMAGE ENHANCEMENT USING EVOLUTIONARY COMPUTING." Thesis, 2014. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15442.
Full textAbstract:
A new method for the enhancement of color images is presented which uses the fuzzy logic and
differential evolution. With the application of an objective measure known as exposure the image
is divided into underexposed and overexposed regions. The V component or the luminance
component of the HSV color space is exploited for the enhancement process. However, the hue
component is kept intact so that the color constitution of the original image remains the same. The
under exposed and the over exposed regions are enhanced using two different schemes. The
enhancement of the underexposed region is done using a parametric sigmoid function whereas the
enhancement of the overexposed region is done using power law transformation. For good
enhancement results, the appropriate values of the parameters of the sigmoid function and the
gamma used in power law transformation function are required. These are optimized using
differential evolution. Moreover, two separate membership functions are used to characterize the
underexposed and the over exposed regions of the image, i.e., Gaussian membership for the
underexposed areas and triangular membership for the overexposed areas. This method becomes
universal for implementation upon all types of contrast degradations because of the use of
separate membership functions and enhancement operators for the two regions. The selfadaptation
of the parameters, based on differential evolution, makes the whole method automatic.
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Hu, Kuo-Jui, and 胡國瑞. "The Study of Color Image Enhancement for Display Device." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54360790272140540794.
Full textAbstract:
博士<br>國防大學理工學院<br>國防科學研究所<br>99<br>The field of imaging technology is currently growing and expanding rapidly. The importance of color image quality therefore is gradually increasing. A color image would have different color appearance and image quality on different displays. The aims of this study are to develop a method to improve the color image quality for displays and to find a way to assess the image quality of the displays with high efficiency.
There are three main contributions in this thesis. The first is to optimize display color quality by means of a color conversion method for preferred color tones to convert original color in a color image into the preferred one with improvement of reducing false contours. Second, an effective and convenient method to enhance the color image quality is developed in the aspects of high dynamic range color processing allowing the displaying magnitude to be compressed by adaptive tone mapping function with preserving the salient features in the scene. Third, an energy consumption issue being studied. One serious challenge preventing color sequential displays replacing conventional liquid crystal display is the color break-up issue. A novel method is developed to reduce the color break-up phenomenon in this thesis.
A number of experiments have been conducted to demonstrate the efficacy of the proposed schemes from color preference treatment, high dynamic range color processing, and color enhancement technology. The results strongly show the promising performance.
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Huang, Da-Yuan, and 黃大源. "Face Beautification and Color Enhancement with Scene Mode Detection." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73998g.
Full textAbstract:
碩士<br>國立臺灣大學<br>資訊工程學研究所<br>98<br>Auto photo beautification such as automatic white balance, noise reduction, and automatic human face beautification play important roles of promoting the quality of photograph because of the popularity of digital image production such as digital camera and printer.
However, due to input image variety, algorithms such as automatic human face beautification and photo color enhancement are hard to automate. Parameters of algorithm usually have to be adjusted manually, and users have to learn how to adjust them. That increases the difficulty of using those products.
In this thesis, we develop a pipeline which combines automatic human face beautification and automatic color enhancement. The goal of this thesis is to beautify human faces and enhance the detail and color of the background of photos. The enhancement methods must produce steady and harmonious results quickly, so that our methods can be implemented on printer and used by users.
Finally, we will select the best-match scene mode based on the color distribution of input image. The printer can use the corresponding profile with the information of the scene; it will make the print-out photos more colorful and vivid.