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Dissertations / Theses on the topic 'RGB to gray scale'
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Mosher, Lance Adams. "Double-exposure gray-scale photolithography." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8592.
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Thesis (M.S.) -- University of Maryland, College Park, 2008.<br>Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Morgan, Brian Carl. "Electrostatic MEMS actuators using gray-scale technology." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3944.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2006.<br>Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Kowalewski, Damian. "Edge-based encoding of gray-scale images." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80305.
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This thesis explores image compression based on visual information contained within the edges. This work is based on an observation that not all the information contained within an image is used by the human brain. Previous works demonstrate methods for reconstructing images adequately using edge information. We exploit the fact that some components of the image can be removed while having little effect on human perception: this is the key basis for the compression developed in this thesis. We first construct compression preserving all the edge information extracted from the image. We then consider the impact of removing some of the edge information to further improve the compression ratio. We direct our attention to two types of information associated with edges: (1) its location and shape, (2) intensity and blur values on each side of the edge. First we propose a method to encode edge location and shape in a most efficient manner. We propose a measure of redundancy to remove edges carrying information already encoded in neighboring edges. Then we consider the compression of intensities and blur associated with each edge. Since the intensity information is quite noisy we show that we can remove the noise and reduce intensity functions to linear functions without significant impact on the quality of a reconstructed image. Finally we introduce a method to encode pattern information not included in edge information to improve the overall quality of the reconstructed image.
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Fetter, Paul. "Heuristics for selecting gray scale morphological structuring elements /." Online version of thesis, 1994. http://hdl.handle.net/1850/11728.
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Kirkpatrick, Erin Jolene. "Green Mind Gray Yard: Micro Scale Assessment of Ecosystem Services." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/884.
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There is a spatial mismatch between the size of the area where people are living and the extent of land needed to ecologically support developed areas. More people are living in urban areas than any time in history, and the resources need to support cities have had to expand to try and meet the demands of increasing urban populations. However, areas of opportunity exist for urban areas to begin to positively contribute towards the available resources in a region. Because a large portion of urban areas is within private control, gaining a baseline understanding of how residents interact with ecosystem services served as basis of this study. Using a survey of residents in the Portland, OR area, correlations between demographic groups and questions regarding their beliefs, attitudes, and behaviors as they relate to vegetation proved that the knowledge of environmental relationships is an important first step in creating pro-environmental behavior. Those reporting a high level of knowledge for ecological system and processes were more likely to value the benefits of vegetation for other associated reasons, such as for recreational activities, aesthetic purposes, and air or water quality. Additionally, survey responses were mapped to spatial data to gain an understanding of the spatial characteristics of neighborhoods in the survey area and how they have changed over time. Overall, the results in the study display trends that can help outreach organizations and municipalities to determine plans to strategically engage the public in a way that could create a net gain in urban ecosystem services.
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Zhou, Zhou. "An advanced gray-scale technology and its applications to micro-devices." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3356395.
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Thesis (Ph. D.)--University of California, San Diego, 2009.<br>Title from first page of PDF file (viewed July 9, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 155-161).
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Boyd, Ashley. "Gray scale assessment of axillary lymph nodes in women suspected of breast cancer." Connect to resource, 2008. http://hdl.handle.net/1811/32194.
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Ganapathiraman, Subburengan. "QUANTIFICATION OF SURFACE DEFECTS USING PRIMARY HIGHLIGHT IN DIFFUSE ANGLE GRAY SCALE IMAGES." UKnowledge, 2005. http://uknowledge.uky.edu/gradschool_theses/348.
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The thesis presented is an effort to gather all possible information of one particular type of common paint defect the seed defect, from gray scale images of highly specular painted surface. The proposed approach in the thesis utilizes a white light source to illuminate the surface and utilizes a camera to capture its gray scale image at different diffused angles. While attempting to explain the physics of highlight formation in terms of location on the surface of a seed defect, the thesis also extends to utilize this information from gray scale images to accurately predict the parameters of seed defects including the height, size and position in real time. Since the primary highlight in a gray scale image is more defined, contrary to the past researches on diffuse angle images that use both primary / seed highlight and mirror highlight to estimate height of the seed, this thesis formulates a theory of highlight translation and estimates the height of seed based on primary / seed highlight. The other common type of surface defect - crater defect, is also addressed in the thesis.
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Summitt, Chris, Sunglin Wang, Soha Namnabat, Lee Johnson, Tom Milster, and Yuzuru Takashima. "Fast fabrication of polymer out-of-plane optical coupler by gray-scale lithography." OPTICAL SOC AMER, 2017. http://hdl.handle.net/10150/625707.
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We report a fabrication process of a polymer, and mirror-based out-of-plane optical coupler. In the process, a pre-formed mirror blank made of a buffer coat material is re-exposed by a laser direct writing tool with low numerical aperture of 0.1. The fabrication process is inherently fast because of the low numerical aperture (NA) process. The surface figure of the mirror is controlled under 0.04 waves in root-mean-square (RMS) at 1.55 mu m wavelength, with mirror angle of 45 +/- 1 degrees. Nominal insertion loss of 8.5dB of the mirror-based coupler was confirmed with polymer waveguides fabricated simultaneously. (C) 2017 Optical Society of America
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Johnson, Jarrett Reed. "Multi-scale investigations of gray treefrong movements patterns of migration, dispersal, and gene flow /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4161.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2005.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 18, 2006) Vita. Includes bibliographical references.
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Su, Po-Chang. "A ROBUST RGB-D SLAM SYSTEM FOR 3D ENVIRONMENT WITH PLANAR SURFACES." UKnowledge, 2013. http://uknowledge.uky.edu/ece_etds/17.
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Simultaneous localization and mapping is the technique to construct a 3D map of unknown environment. With the increasing popularity of RGB-depth (RGB-D) sensors such as the Microsoft Kinect, there have been much research on capturing and reconstructing 3D environments using a movable RGB-D sensor. The key process behind these kinds of simultaneous location and mapping (SLAM) systems is the iterative closest point or ICP algorithm, which is an iterative algorithm that can estimate the rigid movement of the camera based on the captured 3D point clouds. While ICP is a well-studied algorithm, it is problematic when it is used in scanning large planar regions such as wall surfaces in a room. The lack of depth variations on planar surfaces makes the global alignment an ill-conditioned problem. In this thesis, we present a novel approach for registering 3D point clouds by combining both color and depth information. Instead of directly searching for point correspondences among 3D data, the proposed method first extracts features from the RGB images, and then back-projects the features to the 3D space to identify more reliable correspondences. These color correspondences form the initial input to the ICP procedure which then proceeds to refine the alignment. Experimental results show that our proposed approach can achieve better accuracy than existing SLAMs in reconstructing indoor environments with large planar surfaces.
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Morgan, Brian C. "Development of a deep silicon phase Fresnel lens using gray-scale lithography and deep reactive ion etching." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/240.
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Thesis (M.S.) -- University of Maryland, College Park, 2004.<br>Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Ravikumar, Rahul. "Multi-scale texture analysis of remote sensing images using gabor filter banks and wavelet transforms." Thesis, [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3175.
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Valieva, Inna. "Photometric Methods for Autonomous Tree Species Classification and NIR Quality Inspection." Thesis, KTH, Maskinkonstruktion (Inst.), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176266.
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In this paper the brief overview of methods available for individual tree stems quality evaluation and tree species classification has been performed. The use of Near Infrared photometry based on conifer’s canopy reflectance measurement in near infrared range of spectrum has been evaluated for the use in autonomous forest harvesting. Photometric method based on the image processing of the bark pattern has been proposed to perform classification between main construction timber tree species in Scandinavia: Norway spruce (Picea abies) and Scots Pine (Pinus sylvestris). Several feature extraction algorithms have been evaluated, resulting two methods selected: Statistical Analysis using gray level co-occurrence matrix and maximally stable extremal regions feature detector. Feedforward Neural Network with Backpropagation training algorithm and Support Vector Machine classifiers have been implemented and compared. The verification of the proposed algorithm has been performed by real-time testing.
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Fu, Qiang [Verfasser], and Chihao [Akademischer Betreuer] Xu. "New driving schemes of cholesteric liquid crystal display for high speed and uniform gray-scale performance / Qiang Fu. Betreuer: Chihao Xu." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2013. http://d-nb.info/1052909701/34.
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Willingham, Alison N. "Emerging Factors Associated With The Decline Of A Gray Fox Population And Multi-Scale Land Cover Associations Of Mesopredators In The Chicago Metropolitan Area." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1228336802.
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Ström, Bartunek Josef. "FINGERPRINT IMAGE ENHANCEMENT, SEGMENTATION AND MINUTIAE DETECTION." Doctoral thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-11149.
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Prior to 1960's, the fingerprint analysis was carried out manually by human experts and for forensic purposes only. Automated fingerprint identification systems (AFIS) have been developed during the last 50 years. The success of AFIS resulted in that its use expanded beyond forensic applications and became common also in civilian applications. Mobile phones and computers equipped with fingerprint sensing devices for fingerprint-based user identification are common today. Despite the intense development efforts, a major problem in automatic fingerprint identification is to acquire reliable matching features from fingerprint images with poor quality. Images where the fingerprint pattern is heavily degraded usually inhibit the performance of an AFIS system. The performance of AFIS systems is also reduced when matching fingerprints of individuals with large age variations. This doctoral thesis presents contributions within the field of fingerprint image enhancement, segmentation and minutiae detection. The reliability of the extracted fingerprint features is highly dependent on the quality of the obtained fingerprints. Unfortunately, it is not always possible to have access to high quality fingerprints. Therefore, prior to the feature extraction, an enhancement of the quality of fingerprints and a segmentation are performed. The segmentation separates the fingerprint pattern from the background and thus limits possible sources of error due to, for instance, feature outliers. Most enhancement and segmentation techniques are data-driven and therefore based on certain features extracted from the low quality fingerprints at hand. Hence, different types of processing, such as directional filtering, are employed for the enhancement. This thesis contributes by proposing new research both for improving fingerprint matching and for the required pre-processing that improves the extraction of features to be used in fingerprint matching systems. In particular, the majority of enhancement and segmentation methods proposed herein are adaptive to the characteristics of each fingerprint image. Thus, the methods are insensitive towards sensor and fingerprint variability. Furthermore, introduction of the higher order statistics (kurtosis) for fingerprint segmentation is presented. Segmentation of the fingerprint image reduces the computational load by excluding background regions of the fingerprint image from being further processed. Also using a neural network to obtain a more robust minutiae detector with a patch rejection mechanism for speeding up the minutiae detection is presented in this thesis.
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Becer, Huseyin Caner. "A Robust Traffic Sign Recognition System." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612912/index.pdf.
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The traffic sign detection and recognition system is an essential part of the driver warning and assistance systems. In this thesis, traffic sign recognition system is studied. We considered circular, triangular and square Turkish traffic signs. For detection stage, we have two different approaches. In first approach, we assume that the detected signs are available. In the second approach, the region of interest of the traffic sign image is given. Traffic sign is extracted from ROI by using a detection algorithm.
In recognition stage, the ring-partitioned method is implemented. In this method, the traffic sign is divided into rings and the normalized fuzzy histogram is used as an image descriptor. The histograms of these rings are compared with the reference histograms. Ring-partitions provide robustness to rotation because the rotation does not change the histogram of the ring. This is very critical for circle signs because rotation is hard to detect in circle signs. To overcome illumination problem, specified gray scale image is used.
To apply this method to triangle and square signs, the circumscribed circle of these shapes is extracted.
Ring partitioned method is tested for the case where the detected signs are available and the region of interests of the traffic sign is given. The data sets contain about 500 static and video captured images and the images in the data set are taken in daytime.
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Paiva, Maria Stela Veludo de. "Projeto de uma arquitetura de hardware para visualização de imagens digitais." Universidade de São Paulo, 1990. http://www.teses.usp.br/teses/disponiveis/54/54132/tde-19082014-105911/.
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Neste trabalho são apresentadas a implementação e avaliação da aplicação do processador gráfico TMS34010. O objetivo foi o desenvolvimento de um sistema para visualização de imagens com este processador, a ser integrado ao Tomógrafo por Ressonância Magnética, do Departamento de Física e Ciência dos Materiais. A fim de avaliar tanto os aspectos do \"hardware\" quanto às capacidades do processador, foram desenvolvidos dois sistemas: um com 16 cores, e outro com 256 níveis de cinza, ambos contendo uma interface serial para interligação de um \"mouse\" convencional para microcomputadores do tipo PC-AT. Através destes sistemas foram avaliados recursos tais como \"pan\" horizontal e vertical, divisão da tela ao meio, vídeo no modo entrelaçado, transparência, operações lógicas, e instruções de transferência de blocos de \"pixels\"<br>This work describes the implementation and evaluation of a TMS34010 graphics processor based system. The system was developed to be used for the visualization of Magnetic Resonance Images in the MR tomography system under development in our Department. To evaluate the design and the performance of the processor, two systems were developed: one capable to show pictures with 16 simultaneous colors, and a second one able to display pictures with a gray scale of 256 levels. Both systems are equipped with a serial interface supporting a conventional mouse as used for PC compatibles. The hardware developed was used to evaluate implementations of resources such as horizontal and vertical PAN, screen division, interlaced video, transparency, logic operations and pixels block transfer routines
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Baroni, Carina Outi. "Efetividade dos filtros empregados em imagens radiográficas digitais na detecção dos quadros pulmonares de cães e gatos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10137/tde-25092013-151150/.
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A transição do sistema radiográfico convencional para os sistemas radiográficos digitais, ao longo de vinte anos, tem transformado as salas de laudos nos Serviços de Diagnóstico por Imagem tanto na Medicina quanto na Medicina Veterinária. Atualmente, com a introdução do sistema radiográfico computadorizado na rotina de alguns hospitais e laboratório de imagem, o uso das ferramentas do pós-processamento tem se tornado mais freqüente. Diante das vantagens e desvantagens destas ferramentas e da escassez de trabalhos a cerca dos filtros utilizados em imagens radiográficas digitais, o objetivo deste trabalho foi testar o uso dos filtros convencional, realce de borda e invertido, assim como a associação deles na detecção dos padrões pulmonares de cães e gatos. Foram selecionados 40 exames radiográficos do tórax de cães e gatos contendo as três projeções de eleição. Três observadores com diferentes graus de experiência e familiaridade com o sistema radiográfico computadorizado analisaram os filtros individualmente e depois em associação na detecção geral dos padrões pulmanres e individualmente. Obteve-se melhores valores de sensibilidade e especificidade, em geral, quando os observadores experientes utilizaram os três filtros em associação e, para o iniciante, os melhores resultados da sensibilidade e especificidade, em geral, foram no filtro convencional. Os resultados deste trabalho permitiram concluir que houve diferença estatística entre os observadores com distintos graus de experiência e familiaridade com o sistema digital. E que o uso em associação dos filtros pode incrementar o desempenho do radiologista na avaliação radiográfica do parênquima pulmonar.<br>The transition of the conventional radiographic system to the digital one has been transforming the radiographic routine human and veterinary medicine over the last twenty years. Currently, the introduction of the computed radiography system in some hospitals and imaging services has increased the use of post processing tools. Considering the advantages and disadvantages of these tools and the lack of knowledge about the filters used in digital radiographic images, the aim of this study was to test efficacy of the standard, edge enhancement and gray scale reversed filters and their association to detect pulmonary patterns of cats and dogs. This work selected forty canine and feline sets of thoracic radiographs, including three projections. Three different observers with different degrees of experience and familiarity with the computed radiographic system analyzed the filters individually and then associated in order to detect pulmonary patterns. The best results in sensibility and specificity were related to the more experienced observers using the three associated filters. However, for the beginner, the best sensibility and specificity results was reached with the use of the standard filter in general results. In conclusion were statistical differences between more experienced and familiarized observers with the digital system and the use of filters can increase the radiologist performance when evaluating the pulmonary patterns on the radiography.
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Chopra, Sascha Santosh. "Charakterisierung von Lebertumoren nach kontrastverstärkter Sonographie und digitaler Graustufenbestimmung." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2006. http://dx.doi.org/10.18452/15411.
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Charakterisierung von Lebertumoren nach kontrastverstärkter Sonographie und digitaler Graustufenbestimmung Ziel: Die Charakterisierung fokaler Leberläsionen ist Bestandteil des klinischen Alltags und für Patienten von therapeutischer und prognostischer Relevanz. Auf diesem Gebiet wurde bisher die native Sonographie regulär eingesetzt. Eine sichere Artdiagnose bei unklaren Lebertumoren ist jedoch nur selten möglich. Die Einführung der kontrastmittelverstärkten Sonographie hat die differentialdiagnostischen Optionen erweitert. Ziel dieser Studie war es, den Nutzen des kontrastmittelverstärkten Ultraschalls und der anschließenden digitalen Graustufenanalyse bei fokalen Leberläsionen zu bewerten. Methodik: In einer prospektiven Studie wurde bei 50 Patienten mit CT oder MRT gesicherten Lebertumoren eine Sonographie des Oberbauches in nativer Sonographie und in Phaseninversionstechnik mit intravenöser Gabe des Ultraschallkontrastmittels SonoVue® durchgeführt. Nach Kontrastmittelgabe wurden über 120 s digitale Standbilder akquiriert. Mittels Software ermittelte man den dynamischen Graustufenverlauf für jeden einzelnen Tumor. Es folgte der Vergleich der einzelnen bildgebenden Modalitäten untereinander. Ergebnisse: Der Anteil der artdiagnostisch korrekten Zuordnungen belief sich in der CT bzw. MRT auf 78% und in der nativen Sonographie auf 60%. Mit Hilfe des kontrastmittelverstärkten Ultraschalls konnte er auf 86% gesteigert werden. Die digitale Graustufenanalyse lieferte für die einzelnen Tumorentitäten charakteristische Kurvenverläufe. Hierbei erwiesen sich die Zeitpunkte 20 s und 100 s nach Kontrastmittelgabe für die artspezifische Charakterisierung und für die Differenzierung in benigne und maligne Tumoren als optimal. Schlussfolgerung: Die kontrastmittelverstärkte Sonographie und deren digitale Graustufenbestimmung bilden eine Ergänzung der bisherigen Diagnostik von Lebertumoren und ermöglichen eine bessere Charakterisierung der Herde. Dies sollte in zusätzlichen Studien evaluiert werden.<br>Characterization of Hepatic Tumors with Contrast-enhanced Ultrasound and Digital Gray-Scale Analysis Purpose: The characterization of liver tumors is of therapeutic and prognostic relevance. Although ltrasound offers the opportunity to detect hepatic tumors, its previous techniques did not lead towards a definitve differentiation. The purpouse of this study was the evaluation of contrast enhanced ultrasound followed by quantitative digital analysis in patients with focal hepatic tumors. Materials and Methods: In a prospective stuy, 50 patients with liver tumors previously detected by CT or MRI were examined by ultrasound of the upper abdomen using conventional and phase inversion technique after intravenous application of an ultrasound contrast agent. Digital images were stored over 120 s and software powerd digital gray-scale curves were produced for each individual lesion. Results: While the percentage of tumors correctly characterised by CT/MRI amounted to 78%, the percentage increased from 60% using conventional ultrasound to 86% using contrast enhanced ultrasound including gray-scale analysis. Typical graphs were achieved for different tumor entities on digital gray-scale analysis. Time intervals at 20 and 100 seconds showed optimal for differantiation between particualar entities. Conclusion: Quantification of contrast enhanced ultrasound is an addition to the previous diagnostic procedure in hepatic tumors. It offers the possibility of an investigator-independent characterization of lesions and should be evaluated in further studies.
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Huang, Shi-Chuan, and 黃士銓. "Research on Gray Scale Face Recognition." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/88823614922014614502.
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碩士<br>國立交通大學<br>電機與控制工程系<br>90<br>A face recognition algorithm based on a preprocessing units and Eigenfaces approach is proposed in the dissertation. The preprocessing units consist of the following aspects: First, we use Fourier spectrum to detect and compensate the rotation of face image. Second, we apply Sobel edge operator to normalize the face in the image. Third, we utilize homomorphic filter to eliminate the effect of illumination. In the experiments of the dissertation, the ORL database is used as a standard test bench to verify the performance of the proposed face recognition system. By using original ORL database and clipped ORL database we are able to verify proposed algorithm in conjunction with the recognition result. In the present research, both histogram equalization method and homomorphic filter method have been analyzed to compare the effect on the face recognition system. Preliminary results indicated that by using the homomorphic filter to eliminate the illumination effect surely increase the recognition rate of the face recognition system.Note that by applying homomorphic filter to the ORL database can increase 7% in recognition rate . Finally, a two-stage Eigenfaces-based recognition system according to the statistical characteristic of the experiment result and the concept of combining coarse turn and fine turn is established to achieve 95% recognition rate. However, the two-stage system required longer time to obtain higher recognition rate. A future research in building an efficient second stage face recognition is suggested to complete the overall face recognition algorithm.
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Huang, Jhing-Chin, and 黃俊欽. "A Study on Gray Scale Face Recognition." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/82524046368862341001.
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碩士<br>國立交通大學<br>資訊科學學系<br>84<br>An automatic face recognition system is proposed in the
thesis. The system mainly consists of three phases : location,
facial feature extraction and identification. In the face
location phase, we base on the following properties : the
symmetry of human face, the relative positions of hair,
forehead, eyes, nose and mouth in a face, and the
characteristics of the variation of the gray values of those
facial features, to locate the positions of eyes and mouth.
Then, the vertical distance between eyes and mouth is used to
clip out the rough face region. In the second phase, the more
accurate positions of eyeballs and mouth are located. The
rotation effect is adjusted by aligning the center points of
left and right eyes into the equal height. Then, the facial
features are extracted for recognition. In the last phase, we
use the eigenface approach to do recognition. The histogram
equalization is locally used to reduce the effect of
illumination. Experimental results show that the system has a
good recognition rate under complex background, and allowing
translation, small tilt, lighting and scaling changing.
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Liu, Kang-Hung, and 劉康弘. "Design and Fabrication of Gray-Scale Masks." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/53791932178070697866.
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碩士<br>國立交通大學<br>光電工程所<br>88<br>Conventionally, the diffractive optical elements（DOE’s）are produced with a binary multimask lithography-and-etch fabrication process. To generate a multilevel DOE structure with 2n phase level requires n binary masks, n photolithographic processing steps, and n etching steps. The multistep fabrication process is consuming, resulting in a low yield rate, and costly. It also places strict requirements on multimask alignment and etching error. Obviously, the binary multimask-and-etch technique is not practical for fabricating large numbers of DOE phase level for higher diffration efficiencies.
In this thesis we have developed a new technique of gray-scale masks by using halftone techniques. This technique can be applied in micro-optical components fabrication to eliminate the multiple lithographic processes and alignment errors in traditional binary masks fabrication. As a result, the application of micro optical devices should be greatly extended.
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楊忠義. "Decomposition of gray-scale structuring elements with applications." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/03791701902132778925.
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HUANG, HONG-BEN, and 黃宏本. "A study on representations of gray scale images." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/11441015822184322194.
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Pen, Chih-Hsiu, and 賁致修. "The Study of Color to Gray-Scale Image Transform." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/3wpgw5.
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碩士<br>國立中興大學<br>電機工程學系所<br>101<br>Most methods that convert color images to grayscale images use the intensity value directly for the converted grayscale value. When two pixels have different colors but the same intensity values, the conversion causes the original contrast to disappear. In addition, human visual system has a tendency of regarding regions with similar colors or structures as a whole.
To solve the aforementioned problem and incorporating the characteristics of the human visual system into the color conversion, this thesis proposes a color-to-grayscale conversion method that considers the influence between image blocks. The method divides an image into several different blocks to calculate an overall grayscale value for each block. Then, it uses the color of a pixel and the probability that a pixel belongs to each block to better differentiate each pixel after grayscale conversion.
The first step is to divide an image into two blocks. The grayscale value of each block is calculated by minimizing the energy of the difference between the grayscale value after conversion and the color distance before conversion. The second step further divides each block into two subblocks. Each pixel in a subblock is paired with a representative pixel in another subblock. Two weights for the chrominance values are calculated by minimizing the energy of color distances before and after conversion. In the third step, the grayscale value for each block is calculated by combining the grayscale value calculated in the first step, the weighted chrominance values calculated in the second step, and the difference between the intensity values before and after conversion. Finally, the grayscale value for each block is multiplied by the probability that a pixel belongs to each block to form the final grayscale value.
In the experiments, we find that adjusting a parameter in the first step increases the contrasts among different blocks. On the other hand, the probability that a pixel belongs to each block cannot be too small or too large because it makes the influence among block either too weak or too strong. The experimental results show that the method can be adjusted to fit different conversion needs.
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許英傑. "Gray-scale Mircolens Fabricated with Focused-Ion-Beam Mask." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/33102026933574425347.
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碩士<br>國立交通大學<br>電機與控制工程系所<br>94<br>As the progress of information technology, the demand of high capacity and high speed is increasing. Optical data storage technology plays a key role. The application of miniaturization and lightness makes the optical storage system more competitiveness. And Micro-Opto-Electro-Mechanical System (MOEMS) is one of these methods.
MEMS fabrication technology matures by the progress of the semiconductor technology, and micro optical pick-up head fabricated by this technology is one of the methods to realize portable high capacity. In this thesis, the micro optical pick-up head is composed of a micro optical bench and a controllable focusing lens bonded together. The focusing lens is main study in this thesis.
There are two kinds of focusing lens, one is the diffractive type with simple process and low efficiency, and another is the refractive type with complex process and high efficiency. However, as the gray-scale mask progress, the refractive type becomes attractive in micro size. Cause of the limitation of thickness, the hybrid of these two types, Fresnel lens was used. The Fresnel is a special optical component between the refractive and diffractive type.
There are many different mask fabrication process in gray-scale mask, such as the half tone and High Energy Beam Sensitive (HEBS) glass gray-scale mask, and is attractive recently due to the simple lithography process. The gray scale mask to fabricate focusing microlens was made by FIB milling pattern on silicon nitride. The size of the design mircolnes is 100μm, and the numerical aperture is 0.65.
Final target in the thesis is to fabricate microlens by FIB mask, and the size of microlens can reach at least 600μm in diameter. In order to realize the focusing microlens of micro optical pick-up head to integrate the micro optical bench.
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溫亦謙. "Gray Scale Mask Produced by Optical Pick-up Head." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/86124091007715272730.
Full textAbstract:
碩士<br>國立交通大學<br>電機與控制工程系所<br>95<br>There are many different gray scale mask fabrication processes in gray scale mask, such as half tone mask, high energy beam sensitive (HEBS) glass gray scale mask, and laser direct write (LDW) glass gray scale mask. They are attractive recently due to the simple photolithography process. Because the price of the HEBS glass and LDW glass is too expensive, the professional film is used to produce the gray levels by a DVD optical pick-up head.
The DVD optical pick-up head in this thesis is composed of the tracking actuator, the focusing actuator, the objective lens, the photo detector, the laser diode, and so on. The focusing actuator can drive the objective lens in the vertical direction. When the distance is not in focus, the focusing error signal is produced by the photo detector and the PI controller compensates the error. Then, the distance is focused. The tracking actuator driven by the driving circuit actuates the objective lens in the horizontal direction. Because there is no data track in the film, there is no tracking error. Therefore, the movement of the objective just can be controlled by the driving circuit, and the smallest movement is 4.68 μm. The laser diode driven by the driving circuit can emit the different intensity of the laser. Because the numerical aperture of the objective lens is 0.67, the smallest spot size in the film is 0.617 μm. The tracking actuator moves the objective lens to a specific position, and the specific emitting time and power of the laser is emitted by the laser diode. Then, the laser passes through the objective lens, and the spot is focused on the film. The above steps are repeated, and the different value of exposure is received in every position of the film. Gray scale levels are produced in the exposed film through the processing.
The target of the thesis is to produce the gray scale film mask within a 500μm range. the gray scale view can be analyzed by the optical microscope and Matlab.
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Hui, Yu Rong, and 于榮輝. "Adaptive Discrete Cosine Transform Coding of Gray-Scale Images." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/15830412519295635772.
Full textAbstract:
碩士<br>國立中央大學<br>資訊及電子工程研究所<br>82<br>An adaptive cosine transform coding scheme for gray-scale
images based on HVS is proposed in this thesis. Ngan, Leong,
and Singh's approach is adopted in this paper. In our block
adaptive scheme, a new range scale factor function is proposed
to improve the subjective quality of those blocks which contain
edges. Besides, we will propose a new adaptive block-effect
redunction method to reduce the block effect resulting from
block transform coding schemes. This scheme is combined with
perceptual distortion minimization and two-dimensional block
distortion equalization algorithms. Experimental results show
that the subjective quality of the reconstructed images at a
bit rate of 0.4 bit/pixel is very appealing.
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Sheng, Chu Chang, and 曲昌盛. "The Design and Fabricative Technology of Gray-Scale Fresnel Microlens." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/09005451853360614064.
Full textAbstract:
碩士<br>中華大學<br>電機工程學系碩士班<br>87<br>The Fresnel microlens manufactured by gray-scale mask lithography technology is called gray-scale Fresnel microlens. We propose equal-interval quantization in a period to give gray-scale Fresnel microlens the selectivity of linewidth and the controllable quantization phase level. A gray-scale Fresnel microlens is designed, fabricated, and analyzed. At first we infer the optical principles of gray-scale Fresnel microlens from the scalar diffraction theory, and design the gray-scale Fresnel microlens by the use of optical path difference. Secondly, we use near field diffraction theory of circular symmetry to analyze gray-scale Fresnel microlens. The Strehl ratio of the intensity distribution on focal plane, the influences of input wavelength and temperature on gray-scale Fresnel microlens are simulated numerically. Finally, A gray-scale Fresnel microlens is fabricated by gray-scale mask lithography technology, and its specifications: f-number is 30, 240 mm is focal length, 8 mm is lens diameter, and 32 are quantization levels. It is found that the focal length and the spot size on focal plane agree with the numerical results caculated from the near-field diffraction theory of circular symmetry. This proves the focusing properties of the gray-scale Fresnel microlens. In theory, the -1 order diffraction efficiency of the microlens can be 99 %, but the measured value is only 80 %. The degradation is due to the depth and side-wall errors caused by the etching process.
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Lin, Bo-chen, and 林柏辰. "Reflection Vein Recognition System Based on Local Gray-scale Normalization." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/87588580375861322052.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>資訊工程系<br>101<br>Biometrics is a very important research topic in recent years. It is uses unique body feature between different people for identification. The most widely used such as fingerprint recognition, there are other like face, iris, voice, and the most popular of biometrics is vein identification. Vein identification is uses different near-infrared absorption rate of blood hemoglobin and other body tissues, make the vein texture appear for identification. Vein recognition is currently using back, palm and finger vein, the most common is the palm and finger vein. Vein recognition is vital identification so it’s very difficult to forge and fake, and it is also most secure.
This paper will design a finger vein recognition system uses low-cost hardware, expected in the low-quality images can also have higher recognition results. Unlike the general finger vein recognition, this paper uses reflection method to capture vein image. First, decide the ROI from the capture image, then uses local gray-scale normalization for contrast enhancement, and then uses Sobel operator to enhance vein texture. Finally, use SURF for feature extraction and matching.
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Chan, Cheng Che, and 詹政哲. "Feature Extraction Strategy for Face Detection in Gray Scale Image." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/67649605385861151342.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>機械工程系<br>91<br>In recent years, the computer technology is fast developing and advancing. The speed of the computer enables the machine vision can be applied in many areas such as face detection and object tracing. There have been many researches in these fields, but most of them are based on color information. In this study, the technology of image processing aims to detect and trace human face with a web cam in grey scale images.
Most of the previous face detection researches proposed detection methods using skin-color information to find out possible face-like regions. Then recognize face using shape information. In this paper we will propose feature extraction strategy and define the face-features for face detection in grey scale images. Finally, using the simple and fast face survey to filter out surplus regions.
Compared to color image, the information in a grey scale image is less and easilier influenced by the condition of illumination. In order to adapt influence by varied illumination condition, we adjust parameter gains. In this way, the feasibility and the accuracy will not be reduced by poor illumination. The face detection process proposed in this study can detect faces in complex scenes with a fast speed. Our experiments confirm the strength and the reliability of the proposed algorithm. At the end, we discuss the results, and suggestions to future work.
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Leonard, Jeff Jason. "The equal value gray scale applied to laser printer output." 1987. http://catalog.hathitrust.org/api/volumes/oclc/15744319.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 1987.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 38-43).
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Lin, Yu-Hsiang, and 林毓翔. "Material Properties and Stable Gray Scale of Cholesteric Liquid Crystals." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/06636109240622172414.
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碩士<br>國立交通大學<br>光電工程學系<br>100<br>In this thesis, the influence of liquid crystals dielectric anisotropy and viscosity on electro-optical properties are discussed. The stable gray scale can be achieved in the case with surface rubbing. The driving voltage and response time are mainly affected by dielectric anisotropy and viscosity respectively. High dielectric anisotropy and small cell gap will cause low driving voltage, Vth=5.5V, Vsat=9V, Vreset=28V. Decreasing cell gap, however, increases response time from 50 ms to 300 ms due to the strong boundary condition.
In order to achieve gray scale in the case with rubbing, the reflective planar and scattering focal conic state have to be maintained at the same time. Besides, the stability of focal conic state will be affected by surface alignment after removing the driving voltage. 3 multi-level gray scale methods can be achieved via either active or passive driving. The active driving method has the fastest driving time (500 ms) and the most stable gray scale.
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"A new approach to the generation of Gray scale Chinese fonts." Chinese University of Hong Kong, 1993. http://library.cuhk.edu.hk/record=b5887842.
Full textAbstract:
by Poon Chi-cheung.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 1993.<br>Includes bibliographical references (leaves 82-84).<br>Abstract<br>Acknowledgments<br>Preface<br>Chapter Chapter 1: --- Font Systems --- p.1<br>Representations of Character Images --- p.1<br>Characteristics of Chinese Font System --- p.3<br>Large Character Set --- p.3<br>Condensed Strokes --- p.4<br>Low Repetition Rate --- p.5<br>WYSIWYG (What You See Is What You Get) --- p.6<br>Chapter Chapter 2: --- Human Visual System and Gray Scale Font --- p.9<br>Human Visual System --- p.9<br>Physiology --- p.9<br>Spatial Frequencies --- p.10<br>How much resolution is enough --- p.11<br>Screen and Printer --- p.12<br>Raster Display Devices --- p.13<br>Printer --- p.14<br>Resolution --- p.15<br>Gray Scale Font --- p.15<br>Generation of Gray Scale Font --- p.18<br>Chapter Chapter 3: --- Digital Filtering Method for Gray Scale Font --- p.19<br>Filtering Process --- p.19<br>Weighted Functions --- p.21<br>Generation of Gray Scale Character --- p.23<br>Results --- p.24<br>More Experiments --- p.24<br>Problems --- p.26<br>Speed and Storage --- p.26<br>Impression of Strokes --- p.27<br>Thin strokes in the small-size character --- p.30<br>New Approach to Generate Gray Scale Font --- p.30<br>Chapter Chapter 4: --- Rasterization Algorithms --- p.32<br>Outline Font --- p.32<br>TrueType Font --- p.33<br>Scan Conversion --- p.35<br>Basic Outline-to-Bitmap Conversion --- p.35<br>Scan-converting Polygon --- p.36<br>Rasterization of a character --- p.36<br>Intersecting Points and Ranges --- p.37<br>Straight Lines --- p.37<br>Quadratic Bezier Curves --- p.38<br>Implementation Techniques --- p.39<br>Approximation of quadratic Bezier curve by straight lines --- p.39<br>Simplification of the Filling Process --- p.41<br>The Rasterization Algorithm --- p.45<br>Chapter Chapter 5: --- Direct Rasterization with Gray Scale --- p.46<br>Rasterization with Gray Scale --- p.46<br>Determination of Gray Value of Boundary-pixel --- p.50<br>Preliminary Results --- p.54<br>Hinting --- p.56<br>Rasterization with Hinting --- p.56<br>Strokes Migration --- p.57<br>Hints Finding --- p.59<br>Chapter Chapter 6: --- Results and Conclusion --- p.62<br>Quality --- p.66<br>Comparison with Black-and-White Character --- p.66<br>Hinted Against Unhinted --- p.71<br>Generation Speeds --- p.75<br>Discussion and Comments --- p.78<br>Practical Font System --- p.79<br>Conclusion --- p.80<br>Bibliography --- p.82
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陳哲生. "Design of a configurable VLSI chip for gray-scale morphological operations." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/05555799201425972751.
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黃智任. "On the study of gray-scale image segmentation via fuzzy disks." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/78919317925877406755.
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吳育奇. "Gray-scale and color morphological image processing via binary decision diagrams." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/58067306959480891974.
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Jiang, Yao Min, and 江耀民. "A study of face detection in color and gray scale image." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/75944699952213921230.
Full textAbstract:
碩士<br>清雲科技大學<br>電機工程系所<br>96<br>The problem of human face detection has been studied for many years. Although
considerable successes have been achieved, much work remains to be done to devise
improved algorithms. The objectives of this research are proposing a novel scheme
for quasi-skin region face detection in color image and exploring the face detection
reliability of neural network in gray scale image.
In color image, a robust algorithm for face detection based on skin color
segmentation is proposed. A quasi-skin region that connects the human face, neck,
and body is formed while wearing skin color liked clothes. Although we can use
additional eye information, but it will be failed when someone wears a sunglass or
close eyes. The algorithm analyses the distribution curve of the quasi-skin region to
overcome the failure of eye detection. After taking skin color segmentation and
morphological operations of dilation and erosion, statistics curve of binary quasi-skin
region is constructed and the local minimum is found by voting procedures.
Experimental results show the correctness of our algorithm.
In gray scale image, some features of face and eyes are used in training neural
network to perform the face detection. Eye candidates are decided after edge detection
and region growing processes. The face detection results of neural network are
discussed and compared with other algorithms.
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Liu, Che-Wei, and 劉哲瑋. "Automatic Fingerprint Identification System Based on Direct Gray-Scale Image Processing." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/71788007314982342476.
Full textAbstract:
博士<br>淡江大學<br>電機工程學系博士班<br>98<br>Abstract:
Fingerprint is the most popular biometric feature that is widely accepted by the public. Fingerprint is also adopted by the court to be the forensic evidence. Even now, a lot of family and company use a fingerprint recognition system as the access control system. Fingerprints possess two characteristics: Uniqueness and Invariance. The age and the damage on the finger didn’t change the pattern of fingerprint. Therefore, fingerprint can be the identity of individual.
Fingerprint had been researched for several hundred years. The first systematical classifying method of fingerprint was proposed by Henry in 1888. After Henry’s approach, many researchers dedicated on the systematic processing of fingerprint recognition, every kind of theorems and algorithms were developed to solve several fingerprint issues: fingerprint classification, fingerprint orientation fields, fingerprint feature and minutiae, and fingerprint matching.
In this dissertation, we propose a complete automatic fingerprint identification system from the pre-processing: segmentation, normalization, orientation and frequency estimation and singular points extraction. We also propose a new fingerprint classification method, and direct grey scale minutiae detection in fingerprint and the fingerprint matching. We are not only referring some researches in the literature, we also improve the original procedure and propose some new algorithm in the fingerprint processing`.
In the fingerprint pre-processing, we bring up the “Less is More” concept to the fingerprint. The significance of this concept is that pattern possess small portion in the fingerprint block would decide the characteristic of fingerprint texture. As an instance, if a finger pressed too hard on the fingerprint acquiring sensor, we will acquire a smudged fingerprint. The width of ridge lines will become too wide even can connect to other ridges. In this situation, the pixels belong to the ridge line take large portion in the fingerprint pattern. If we trace the ridge lines in the fingerprint, we will extract a lot of false minutiae. Hence, we enhance the information that takes less part of fingerprint which is the valley line in this case, and then we can extract the fingerprint features more correct.
In the fingerprint classification, we illustrate the concept form data-mining to propose a new fingerprint classifying and indexing method. Our method can co-operate with Henry’s classification or work individually. By the statistical data of fingerprints, over 95 percents of fingerprint contain an upper core. We calculate the frequency around the upper core and classify fingerprints to 37 classes. We design a hierarchical structure for fingerprint indexing form the class that has the largest probability of matching to those classes that have smaller probability. Our method improves the traditional classification that we have to search the entire database while the input fingerprint is incorrectly classified. We arrange those classes in the different indexing level from high probability to low. In our fingerprint indexing verification, we can acquire more than 90% of matching rate in the first three levels.
In the fingerprint minutiae extraction, we didn’t use traditional binarizing method to detect the minutiae, but direct extract minutiae on the grey scale image. Because the grey level image contains more information about fingerprint texture and significant amount of information may be lost during the binarization process. The binarization and thinning are time consuming; the thinning process may generate a large number of spurious minutiae. In the absence of an a priori enhancement step, most of the binarization techniques do not provide satisfactory results when applied to low-quality images. We propose two level minutiae extracting process, in the first level; we mark the peak and trough on the fingerprint histogram to indicate the position of ridge lines and valley lines. And we employ the “Less is more” concept that those textures will be enhanced by the pattern that takes fewer portions. In the second level, we link those points to extend the ridge lines and valley lines and then we can extract minutiae form the trace of ridge lines.
In the fingerprint matching process, we proposed the polar coordinate system to represent the minutiae of fingerprint and match those minutiae with a pre-alignment process. This matching algorithm is very fast that we can match more than 10000 fingerprint templates within one second. In the same time, we still can keep good accuracy of fingerprint matching.
In the last chapter, we discuss some issues about the processing of blurred or fragmental fingerprint and the future works. We also share some experience and the strategy that we design this system.
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Guo, Jhih-Peng, and 郭志鵬. "Parallel Gray-Scale Co-occurrence Matrix Algorithm Based on Graphics Processor." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/fnv786.
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碩士<br>靜宜大學<br>資訊工程學系<br>107<br>To analysis Magnetic Resonance images, the initial step is to extract textures from the original images according to a variety of features. However, most of the texture extraction algorithms are computational-consuming approaches. GLRLM is the one of common-used architectures and the computational cost of the extraction functions during the pre-processing phase is very expensive. Recently, GPU technology is booming and also the ideal choice to accelerate the current computing process. In this study, we provide an example of a mature parallel primitive that is used to generate a GLRLM and simultaneously extract multiple features for multiple region of interesting in the image. The proposed algorithm is very easy to implement, and the optimized speed ratio can be increased by more than 5 times compared to GLRLM executing on CPU from experimental results.
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Wang, Shun-Shien, and 王順賢. "Scale- and Orientation- Invariant Product Recognition Using Improved Radial Coding and RGB Histogram Features." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/19514686638306855606.
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碩士<br>國立臺北科技大學<br>機電整合研究所<br>91<br>In order to reduce the cost of manpower on man-made classification of the production line, in the study, we develop an automatic product classification and recognition system equipped with a simple CCD to solve the problem. In the product recognition process, the main problem lies on the product multiplicity and similarity, which involves the size, rotation degree, and location of products. To overcome the problem and to develop an automatic recognition system, we propose several improved algorithms in the thesis.
The developed system includes two steps, One is the product characteristic learning step and the other is product recognition step. In learning step, first we use the moment invariant to compute the product center and size, then we use the improved radial code efficiently to develop the scale- and orientation-invariant characteristics of the product shape, after performing improved radial code processing, we also extract the histogram in the normalized color rgb model to represent the texture on the surface of product; finally, all the product size, shape, color texture information etc, acted as major features, are stored into the database. In the recognition step, we use similarity measures to recognize the product by comparing the features learned in the database.
Several experimental results are included to show the proposed approach is feasible and practical.
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Alhazmi, Manal. "Fabrication and Characterization of Metal- Insulator -Metal Diode and Gray scale Lithography." Thesis, 2013. http://hdl.handle.net/10012/8042.
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The objective of this thesis is to successfully design, fabricate, and characterize an optimum metal-insulator-metal diode that can be used as a fast switching diode in various applications such as solar energy conversion. The improvements of this type of diode will result in rectification of a wider spectrum of AC signals to usable electricity. In this project, several proposed designs of MIM diodes were successfully fabricated and characterized. Pt-Al2O3-Al metal-insulator-metal diode was fabricated to have high asymmetry in I-V curve. Additionally, in an attempt to study the effect of material properties on MIM diode???s performance, four different combinations of MIIIIM diode were compared and discussed. Many processes were involved in the fabrication of these diodes such as E-beam evaporation, photolithography, reactive ion etching RIE, and Atomic Layer Deposition (ALD) technique. The fabricated tunneling diodes are intended to operate in the GHz regime and can also operate at higher frequencies (THz) by changing and scaling the dimensions.
In addition to MIM diode work, this project attempted to engineer the contrast curve of polystyrene as a negative resist used for E-beam lithography using multi layer resist stack. If the resist stack has a very high contrast and its sensitivity differs between the various layers, it can be ideal for the fabrication of multi-level zone-plate/Fresnel lens.
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Shi, Allen, and 施彥任. "A New Fingerprinting System Based on Gray Scale Watermarking and Hamming Code." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/59984088015382296787.
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碩士<br>國立臺中技術學院<br>多媒體設計研究所<br>94<br>As the internet becomes more and more popular, there is also an increased use of digital
images on it. However, protecting intellectual property rights and keeping tracks of
end-users with rights to use similar copies of a digital image have become extremely
important and urgent. To prevent piracies of images, finger printing techniques have been
applied to images before they are being distributed. The fingerprint can be a unique ID that
will be hidden in each image. The fingerprint can be retrieved later on to prove the
ownership of the image or who the legal users are. However users could collude to tamper
with the images to generate copies of tampered images for illegal purposes. One collusion
method is to take parts from different legal copies and pieced them together to form a
newly colluded image. That is the colluded image contained parts from several authentic
fingerprinted images. Another kind of collusion is to average each overlapping pixels from
several legal copies to create a colluded copy. The hidden fingerprints would be corrupted
in the colluded images from being made up of parts from several other fingerprint images
or by averaging, respectively. In this thesis, the proposed fingerprint technique applies the
discrete cosine wavelet transform on the original image whereby a gray fingerprint image
would be hidden in the transformed domain. The gray fingerprint image consists of a
unique ID code. During recovery, Hamming code is used to improve the quality of the
recovered fingerprint ID in the event it is corrupted by collusion. Experimental results
show that the fingerprint technique is resistant to collusion attacks. In fact the IDs of the
colluders could be identified and used to prove the rightful ownership of the image and also
to pinpoint the colluders.
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Hsu, Ting-Wan, and 許婷婉. "The Pixel Gray Scale Evaluation on Breast Density for Constant Digital Mammography." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/65199910959930783209.
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碩士<br>中臺科技大學<br>醫學影像暨放射科學系暨研究所<br>103<br>In recent years, many studies show that the importance of the breast density, because mammographic sensitivity is inversely breast density, that the observed higher relative risk was solely due to mass obscuration by dense tissues at mammography. To retrospectively collect 452 women received two screenings had 904 digital mammography images, the age range of 27 years to 79 year old. There were two ways to measure the breast density, Qualitative estimates determined by a qualified breast radiologist using the BI-RADS Categorical Assessment scale. Quantitative analysis the percentage breast density using computer software ImageJ. The results show that quantitative methods of experimental design in different ages for its two-year breast degree of degradation: <40 years was 9.73%, 40 to 49 years old was 8.95%, 50 to 59 years was 9.32%, 6.83% 60 to 69 years,> 70 years was 5.07%. The student pair t-test was used for the statistics with the aids of SPSS, p=0.001. The results show breast density was significant difference for different age groups at constant digital mammography. It can be also applied to the clinical for breast density follow, as it is a remarkable indication for the risk of breast cancer.
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Lin, Tai-Ming, and 林代明. "PWM GRAY SCALE PIXEL CIRCUIT ANALYSIS AND SIMULATION FOR LTPS AMOLED PANEL." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/53079337094939498514.
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碩士<br>大同大學<br>通訊工程研究所<br>93<br>OLED is the promising flat panel display in the future. In this thesis, we adopt the Cadence simulator to analyze and simulate the proposed PWM gray scale pixel circuit based on Hitachi developed “Clamping Inverter Driving Circuit” to represent full color display, with modification for moving picture performance improvement, moreover a ac-driving method to prolong the OLED lifetime is included.
The separate R, G, B emitters are adopted to display the full color and the pixel driving circuit are implemented by LTPS fabrication process, the component models are set up by CHUNGHWA PICTURE TUBES Ltd. The column driver LSI ( Novatek NT3947) and video processor chip (MXIC, MX88V44.) are now available to make the whole circuit design easily.
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Yu, Ti-Wei, and 尤迪葳. "Quantifying the Echogenicity of Various Gray Scale Levels on B-mode Ultrasound." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/f5c5w9.
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碩士<br>國立交通大學<br>生醫工程研究所<br>105<br>Ultrasonic imaging systems produce images based on the pulse-echo principle. Ultrasound is transmitted in pulses into tissue to be imaged, and returning echoes detected. The intensity of the returning echoes is then converted to gray scale and displayed on ultrasound diagnostic equipment. Due to the large range of echo intensities encountered, and the fact that the majority of the information present is in the weaker echoes, the gray scale conversion process is highly nonlinear. A rough experimental method is described that allows one to estimate the nonlinear conversion process through a series of measurements. Being able to derive this process allows one to estimate relative echo strengths from ultrasonic images alone, and to be able to quantitatively estimate such strengths based solely on image data.
The experimental method of this study, involves, at the outset, the acquisition of a series of ultrasonic images from the equipment. The images include those with two different attenuations (0.5 dB/cm-MHz and 0.7 dB/cm-MHz) and 5 different echogenicities in cylinders differing from the background (-9, -6, -3, +3, and +6 dB). After determining the average value of each cylinder with a custom function, another custom function was developed that mapped each pixel with a relative echo value taking into account attenuation for up to five cylinders under two attenuation levels.
The purpose of this experiment is that to find software mechanism that we can produce a means for quantifying echo intensities from ultrasonic imaging systems.
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Chang, Wen Cheng, and 張文政. "Gray-Scale Measurement and Compensation of Active-Matrix Organic Light-Emitting Diode." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/e62843.
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碩士<br>國立臺北科技大學<br>光電工程系研究所<br>103<br>An external algorithm with sensing circuit are proposed to compensate AMOLED display degradation. The compensation is enabled by first evaluating gray-scale level of OLEDs based on the OLED lightness detected by the photo sensor. According to sensed voltages, the external algorithm selects appropriate value to compensate OLED degradation with the aim to achieve expected OLED emitted luminance.
The models are established based on prior measurements to describe the relations between luminance and voltage of each OLED. In this way of compensation, the proposed method is able to compensate the decay in OLED luminance.
Moreover, another algorithm along with the resistance circuit as presented in prior are adopted to get variation in voltage variation compared with the AMOLED circuit.
Experiments are conducted by combining the external algorithm with sensing circuit and the compensated circuit to validate the performances of compensating and alleviating OLED degradation to 3~7%,about 2~3 gray-scale.
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ZHAO, WEI-GANG, and 趙維岡. "Mesh Editing Via Vertex Insertion and Displacement Based on Gray Scale Images." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/crgtju.
Full textAbstract:
碩士<br>大同大學<br>資訊工程學系(所)<br>107<br>There are many ways to change the appearance of a model in many modeling software. Each method requires different conditions or difficulty. In the case of making a triangular mesh into a desired pattern on the surface of the model, it is usually only in a slow way.
In this paper, the triangular mesh of the model surface is changed to form a graph, and the process is simple and rapid. The paper discusses the establishment of material coordinates, the search for graphic regions, and the reconstruction of triangular meshes.