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Journal articles on the topic 'Image distortion'

Author: Grafiati

Published: 4 June 2021

Last updated: 6 February 2022

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1

Pollak, C., T. Stubbings, and H. Hutter. "Differential Image Distortion Correction." Microscopy and Microanalysis 7, no. 4 (2001): 335–40. http://dx.doi.org/10.1007/s10005-001-0007-1.

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AbstractImaging techniques often suffer from distortion effects. Former methods of reducing these distortions have been based either on improving the imaging technique (i.e., to avoid distortions) or on the use of reference samples (i.e., to determine the distortion field by imaging of a known structure. We present a novel method of correcting image distortion by evaluating the imaged position changes due to two small sample position shifts. The algorithm allows us to calculate a vector field, which enables us to determine the “undistorted” position of any point of the image. The presented met

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Chen, Xiaohong, Qian Sun, and Jun Hu. "Generation of Complete SAR Geometric Distortion Maps Based on DEM and Neighbor Gradient Algorithm." Applied Sciences 8, no. 11 (2018): 2206. http://dx.doi.org/10.3390/app8112206.

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Radar-specific imaging geometric distortions (including foreshortening, layover, and shadow) that occur in synthetic aperture radar (SAR) images acquired over mountainous areas have a negative impact on the suitability of the interferometric SAR (InSAR) technique to monitor landslides. To address this issue, many distortion simulation methods have been presented to predict the areas in which distortions will occur before processing the SAR image. However, the layover and shadow regions are constituted by active as well as passive subregions. Since passive distortions are caused by active disto

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Ekpar, Frank, Masaaki Yoneda, and Hiroyuki Hase. "Correcting Distortions in Panoramic Images Using Constructive Neural Networks." International Journal of Neural Systems 13, no. 04 (2003): 239–50. http://dx.doi.org/10.1142/s0129065703001601.

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This paper presents a novel approach to the correction of panoramic (wide-angle) image distortions. Unlike traditional methods that separate the distortion of the panoramic image into radial and tangential components and then concentrate on the correction of one type of distortion at a time, the method presented in this paper uses an integrated approach that simultaneously corrects all non-linear distortions of the panoramic image. The system uses data obtained from carefully constructed calibration patterns to automatically build and train a constructive neural network of suitable complexity

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Asatryan, D. G., M. E. Harutyunyan, Y. I. Golub, and V. V. Starovoitov. "Influence of the distortion type on the image quality assessment when reducing its sizes." «System analysis and applied information science», no. 3 (September 25, 2020): 22–27. http://dx.doi.org/10.21122/2309-4923-2020-3-22-27.

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In this paper, the influence of various types of distortion of an image on its quality while reducing its sizes, is investigated. To assess the image quality, it is proposed to use the method of comparison with the standard using a previously developed measure based on the proximity of the values of the parameters of the Weibull distribution, which describes the gradient field of the image. The well-known TID2013 image database was used as the material, which includes 3000 images distorted by 24 types of distorting algorithms with five levels. Each image of the base was reduced by 2, 4 and 8 t

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Jung, Young-Hwa, Gyuho Kim, and Woo Sik Yoo. "Study on Distortion Compensation of Underwater Archaeological Images Acquired through a Fisheye Lens and Practical Suggestions for Underwater Photography - A Case of Taean Mado Shipwreck No. 1 and No. 2 -." Journal of Conservation Science 37, no. 4 (2021): 312–21. http://dx.doi.org/10.12654/jcs.2021.37.4.01.

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Underwater archaeology relies heavily on photography and video image recording during surveillances and excavations like ordinary archaeological studies on land. All underwater images suffer poor image quality and distortions due to poor visibility, low contrast and blur, caused by differences in refractive indices of water and air, properties of selected lenses and shapes of viewports. In the Yellow Sea (between mainland China and the Korean peninsula), the visibility underwater is far less than 1 m, typically in the range of 30 cm to 50 cm, on even a clear day, due to very high turbidity. Fo

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Peng, Fu Qiang, Qiang Chen, and Jun Wei Bao. "Distortion Correction for the Gun Barrel Bore Panoramic Image." Applied Mechanics and Materials 427-429 (September 2013): 680–85. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.680.

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Single Reflector Panoramic Imaging System (SRPIS) has been widely used because of its advantages such as simple structure, fast imaging, integration and miniaturization. It can observe objects around the reflector mirror, which fits for the quality inspection of gun barrel bore. However, its images often suffer from serious distortions in radial and tangential directions. Therefore, to ensure the accuracy of captured images, distortion must be eliminated. In this paper, a distortion correction method is proposed based on the imaging characteristics of SRPIS. Firstly the relationship between th

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Belov, A. M., and A. Y. Denisova. "Scene distortion detection algorithm using multitemporal remote sensing images." Computer Optics 43, no. 5 (2019): 869–85. http://dx.doi.org/10.18287/2412-6179-2019-43-5-869-885.

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Multitemporal remote sensing images of a particular territory might include accidental scene distortions. Scene distortion is a significant local brightness change caused by the scene overlap with some opaque object or a natural phenomenon coincident with the moment of image capture, for example, clouds and shadows. The fact that different images of the scene are obtained at different instants of time makes the appearance, location and shape of scene distortions accidental. In this article we propose an algorithm for detecting accidental scene distortions using a dataset of multitemporal remot

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Saifeldeen, Abdalmajeed, Shu Hong Jiao, and Wei Liu. "Entirely Blind Image Quality Assessment Estimator." Applied Mechanics and Materials 543-547 (March 2014): 2496–99. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.2496.

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Prior knowledge about anticipated distortions and their corresponding human opinion scores is needed in the most general purpose no-reference image quality assessment algorithms. When creating the model, all distortion types may not be existed. Predicting the quality of distorted images in practical no-reference image quality assessment algorithms is devised without prior knowledge about images or their distortions. In this study, a blind/no-reference opinion and distortion unaware image quality assessment algorithm based on natural scenes is developed. The proposed approach uses a set of nove

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Yahanda, Alexander T., Timothy J. Goble, Peter T. Sylvester, et al. "Impact of 3-Dimensional Versus 2-Dimensional Image Distortion Correction on Stereotactic Neurosurgical Navigation Image Fusion Reliability for Images Acquired With Intraoperative Magnetic Resonance Imaging." Operative Neurosurgery 19, no. 5 (2020): 599–607. http://dx.doi.org/10.1093/ons/opaa152.

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Abstract BACKGROUND Fusion of preoperative and intraoperative magnetic resonance imaging (iMRI) studies during stereotactic navigation may be very useful for procedures such as tumor resections but can be subject to error because of image distortion. OBJECTIVE To assess the impact of 3-dimensional (3D) vs 2-dimensional (2D) image distortion correction on the accuracy of auto-merge image fusion for stereotactic neurosurgical images acquired with iMRI using a head phantom in different surgical positions. METHODS T1-weighted intraoperative images of the head phantom were obtained using 1.5T iMRI.

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Archip, Neculai, Olivier Clatz, Stephen Whalen, et al. "Compensation of Geometric Distortion Effects on Intraoperative Magnetic Resonance Imaging for Enhanced Visualization in Image-guided Neurosurgery." Operative Neurosurgery 62, suppl_1 (2008): ONS209—ONS216. http://dx.doi.org/10.1227/01.neu.0000317395.08466.e6.

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Abstract Objective: Preoperative magnetic resonance imaging (MRI), functional MRI, diffusion tensor MRI, magnetic resonance spectroscopy, and positron-emission tomographic scans may be aligned to intraoperative MRI to enhance visualization and navigation during image-guided neurosurgery. However, several effects (both machine- and patient-induced distortions) lead to significant geometric distortion of intraoperative MRI. Therefore, a precise alignment of these image modalities requires correction of the geometric distortion. We propose and evaluate a novel method to compensate for the geometr

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Feng, Liang Shan, Ying Ping Huang, Zhu Kai Xu, and Yong Zhang. "Image Calibration for Machine Vision Inspection System." Applied Mechanics and Materials 556-562 (May 2014): 2841–45. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.2841.

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Machine vision system has been widely used for a variety of applications in industrial testing and measurements. However, image distortion caused by optical system and system re-positioning will bring errors to the machine vision detection system. This paper addresses on three types of image distortions including optical distortion and perspective deformation, image translation and rotation, and image scale change. To rectify optical distortion and perspective deformation, a black and white grid pattern is used as a standard template for finding the multiple matching points between distorted i

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BROWN, MICHAEL S., and YAU-CHAT TSOI. "DISTORTION REMOVAL FOR CAMERA-IMAGED PRINT MATERIALS USING BOUNDARY INTERPOLATION." International Journal of Image and Graphics 05, no. 02 (2005): 311–28. http://dx.doi.org/10.1142/s021946780500177x.

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Camera-based imaging is used to digitize printed materials whose shape and size are not suitable for flatbed and Xerox scanning. Because these materials are not physically pressed flat before imaging, the resulting imaged content often appears distorted due to the material's underlying shape. We present a novel approach to correct common image distortions that arise in camera-imaged printed materials. Our approach uses the boundary information of the imaged material to compute a corrective warp to undo the distortion. Our algorithm is unique in that it simultaneously corrects for a variety of

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Hwang, Alex D., and Eli Peli. "Stereoscopic Three-dimensional Optic Flow Distortions Caused by Mismatches Between Image Acquisition and Display Parameters." Journal of Imaging Science and Technology 63, no. 6 (2019): 60412–1. http://dx.doi.org/10.2352/j.imagingsci.technol.2019.63.6.060412.

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Abstract We analyzed the impact of common stereoscopic three-dimensional (S3D) depth distortion on S3D optic flow in virtual reality environments. The depth distortion is introduced by mismatches between the image acquisition and display parameters. The results show that such S3D distortions induce large S3D optic flow distortions and may even induce partial/full optic flow reversal within a certain depth range, depending on the viewer’s moving speed and the magnitude of S3D distortion. We hypothesize that the S3D optic flow distortion may be a source of intra-sensory conflict that could be a

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Sazzad, Z. M. Parvez, Roushain Akhter, J. Baltes, and Y. Horita. "Objective No-Reference Stereoscopic Image Quality Prediction Based on 2D Image Features and Relative Disparity." Advances in Multimedia 2012 (2012): 1–16. http://dx.doi.org/10.1155/2012/256130.

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Stereoscopic images are widely used to enhance the viewing experience of three-dimensional (3D) imaging and communication system. In this paper, we propose an image feature and disparity dependent quality evaluation metric, which incorporates human visible system characteristics. We believe perceived distortions and disparity of any stereoscopic image are strongly dependent on local features, such as edge (i.e., nonplane areas of an image) and nonedge (i.e., plane areas of an image) areas within the image. Therefore, a no-reference perceptual quality assessment method is developed for JPEG cod

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Del Gallego, Neil Patrick, Joel Ilao, and Macario Cordel. "Blind First-Order Perspective Distortion Correction Using Parallel Convolutional Neural Networks." Sensors 20, no. 17 (2020): 4898. http://dx.doi.org/10.3390/s20174898.

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In this work, we present a network architecture with parallel convolutional neural networks (CNN) for removing perspective distortion in images. While other works generate corrected images through the use of generative adversarial networks or encoder-decoder networks, we propose a method wherein three CNNs are trained in parallel, to predict a certain element pair in the 3×3 transformation matrix, M^. The corrected image is produced by transforming the distorted input image using M^−1. The networks are trained from our generated distorted image dataset using KITTI images. Experimental results

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De, Kanjar, and Masilamani V. "NO-REFERENCE IMAGE QUALITY MEASURE FOR IMAGES WITH MULTIPLE DISTORTIONS USING RANDOM FORESTS FOR MULTI METHOD FUSION." Image Analysis & Stereology 37, no. 2 (2018): 105. http://dx.doi.org/10.5566/ias.1534.

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Over the years image quality assessment is one of the active area of research in image processing. Distortion in images can be caused by various sources like noise, blur, transmission channel errors, compression artifacts etc. Image distortions can occur during the image acquisition process (blur/noise), image compression (ringing and blocking artifacts) or during the transmission process. A single image can be distorted by multiple sources and assessing quality of such images is an extremely challenging task. The human visual system can easily identify image quality in such cases, but for a c

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Reino, Anthony J., William Lawson, Baxter J. Garcia, and Robert J. Greenstein. "Three Dimensional Video Imaging for Endoscopic Sinus Surgery and Diagnosis." American Journal of Rhinology 9, no. 4 (1995): 197–202. http://dx.doi.org/10.2500/105065895781873746.

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Technological advances in video imaging over the last decade have resulted in remarkable additions to the armamentarium of instrumentation for the otolaryngologist. The use of video cameras and computer generated imaging in the operating room and office is invaluable for documentation and teaching purposes. Despite the obvious advantages of these systems, problems are evident, the most serious of which include image distortion and inability to judge depth of field. For more than 6 decades 3D imaging has been neither technically nor commercially successful. Reasons include alignment difficultie

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Zhang, Yin, Xuehan Bai, Junhua Yan, et al. "No-Reference Image Quality Assessment Based on Multi-Order Gradients Statistics." Journal of Imaging Science and Technology 64, no. 1 (2020): 10505–1. http://dx.doi.org/10.2352/j.imagingsci.technol.2020.64.1.010505.

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Abstract A new blind image quality assessment method called No-Reference Image Quality Assessment Based on Multi-Order Gradients Statistics is proposed, which is aimed at solving the problem that the existing no-reference image quality assessment methods cannot determine the type of image distortion and that the quality evaluation has poor robustness for different types of distortion. In this article, an 18-dimensional image feature vector is constructed from gradient magnitude features, relative gradient orientation features, and relative gradient magnitude features over two scales and three

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Dadras Javan, F., F. Samadzadegan, S. Mehravar, and A. Toosi. "A REVIEW ON SPATIAL QUALITY ASSESSMENT METHODS FOR EVALUATION OF PAN-SHARPENED SATELLITE IMAGERY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W18 (October 18, 2019): 255–61. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w18-255-2019.

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Abstract. Nowadays, high-resolution fused satellite imagery is widely used in multiple remote sensing applications. Although the spectral quality of pan-sharpened images plays an important role in many applications, spatial quality becomes more important in numerous cases. The high spatial quality of the fused image is essential for extraction, identification and reconstruction of significant image objects, and will result in producing high-quality large scale maps especially in the urban areas. This paper introduces the most sensitive and effective methods in detecting the spatial distortion

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Pollak, C., T. Stubbings, and H. Hutter. "Differential Image Distortion Correction." Microscopy and Microanalysis 7, no. 04 (2001): 335–40. http://dx.doi.org/10.1017/s1431927601010327.

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Chakraborty, Dev P. "Image intensifier distortion correction." Medical Physics 14, no. 2 (1987): 249–52. http://dx.doi.org/10.1118/1.596078.

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Ponomarenko, Mykola, Oleg Ieremeiev, Vladimir Lukin, and Karen Egiazarian. "An expandable image database for evaluation of full-reference image visual quality metrics." Electronic Imaging 2020, no. 10 (2020): 137–1. http://dx.doi.org/10.2352/issn.2470-1173.2020.10.ipas-137.

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Traditional approach to collect mean opinion score (MOS) values for evaluation of full-reference image quality metrics has two serious drawbacks. The first drawback is a nonlinearity of MOS, only partially compensated by the use of rank order correlation coefficients in a further analysis. The second drawback are limitations on number of distortion types and distortion levels in image database imposed by a maximum allowed time to carry out an experiment. One of the largest of databases used for this purpose, TID2013, has almost reached these limitations, which makes an extension of TID2013 wit

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Mahmoudi, Arshiya, Mehdi Sabzehparvar, and Mahdi Mortazavi. "A virtual environment for evaluation of computer vision algorithms under general airborne camera imperfections." Journal of Navigation 74, no. 4 (2021): 801–21. http://dx.doi.org/10.1017/s0373463321000060.

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AbstractThis paper describes a camera simulation framework for validating machine vision algorithms under general airborne camera imperfections. Lens distortion, image delay, rolling shutter, motion blur, interlacing, vignetting, image noise, and light level are modelled. This is the first simulation that considers all temporal distortions jointly, along with static lens distortions in an online manner. Several innovations are proposed including a motion tracking system allowing the camera to follow the flight log with eligible derivatives. A reverse pipeline, relating each pixel in the output

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Li, Yuan Jin, Hua Zhong Shu, Tao Wang, Yang Wang, and You Yong Kong. "An Integrated Method for XRII Image Distortion Correction." Applied Mechanics and Materials 742 (March 2015): 252–56. http://dx.doi.org/10.4028/www.scientific.net/amm.742.252.

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The distorted X-Ray Image Intensifier (XRII) image can introduce negative effect on following work for C-arm CT imaging system. In this paper, we propose an integrated approach based on least squares and Biharmonic spline interpolation to correct geometric distortions of XRII images. The method first uses morphology operation to extract the coordinate values of control points. Then the least square method fits the extracted coordinate values in every row and computes the more coordinate values by fixing the length in every row. Finally, The Biharmonic spline interpolation is used to interpolat

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Gupta, Praful, Christos Bampis, Jack Glover, Nicholas Paulter, and Alan Bovik. "Multivariate Statistical Approach to Image Quality Tasks." Journal of Imaging 4, no. 10 (2018): 117. http://dx.doi.org/10.3390/jimaging4100117.

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Many existing natural scene statistics-based no reference image quality assessment (NR IQA) algorithms employ univariate parametric distributions to capture the statistical inconsistencies of bandpass distorted image coefficients. Here, we propose a multivariate model of natural image coefficients expressed in the bandpass spatial domain that has the potential to capture higher order correlations that may be induced by the presence of distortions. We analyze how the parameters of the multivariate model are affected by different distortion types, and we show their ability to capture distortion-

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Xing, Ji Sheng, Gang Wang, Shi Gang Wang, Wen Hai Zhuang, and Jin Zhong Wu. "CCD Image Geometrical Distortion Correct and Large Touch Screen." Advanced Materials Research 488-489 (March 2012): 1323–28. http://dx.doi.org/10.4028/www.scientific.net/amr.488-489.1323.

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There are geometric distortions in all the images produced by the CCD camera lens, and the distortions are all nonlinear. Coordinate conversion is an effective method for geometric correction. The calculations will boost as the higher degrees of the polynomial. It is impossible to apply directly in real time correction system. This article introduces a correction according to divided areas through linear polynomial on the base of higher degree polynomial coordinate conversions. In the method the image is divided into uneven loop like areas at first. In each area you can take a linear polynomia

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Liu, Shuang, Ming Cai Shan, and Xiang Jie Kong. "Distortion Analysis in the Axial Offset Parallel Video System." Applied Mechanics and Materials 644-650 (September 2014): 1498–501. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.1498.

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This paper discusses the origins of image distortions in the axial offset parallel video system and how to improve viewing comfort. The types and characteristics of image distortions in some stereoscopic video systems are presented first. The geometry equations of stereoscopic camera and display systems are deduced then. The typical distortions in the axial offset parallel video system can be got and the key factors of image distortions can be found out by the analysis on these equations. These distortions include depth non-linearity, puppet theater effect and cardboard effect, shearing distor

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Kim, J. Y., and J. S. Yoon. "Image Distortion Compensation by Using a Polynomial Model in an X-Ray Digital Tomosynthesis System." Key Engineering Materials 297-300 (November 2005): 2034–39. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.2034.

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X-ray technology has been widely used in a number of industrial applications for monitoring and inspecting inner defects which can hardly be found by normal vision systems as a ball grid array (BGA) or a flip chip array (FCA). Digital tomosynthesis (DT) is one of the most useful X-ray cross-sectional imaging methods for PCB inspection, and it usually uses an X-ray image intensifier. However, the image intensifier distorts X-ray images severely both of shape and intensity. This distortion breaks the correspondences between those images and prevents us from acquiring accurate cross-section image

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Zhang, Jing, and Guang Xue Chen. "Research on the Geometric Distortion Auto-Correction Algorithm for Image Scanned." Applied Mechanics and Materials 644-650 (September 2014): 4477–81. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.4477.

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In the process of gaining digital images whether scanning or photographing, the rugged manuscript or the nonlinear characteristic of the camera lens, etc. may lead to severe geometric distortions of the captured images. Therefore, geometric rectification of the distorted images is necessary before they can be further processed. In this paper, A careful analysis was done on the cases of geometric distortion, and then an auto-correction method is deduced. In the correction process for image scanned, global thresholding was used to extract the feature region which was needed, use Sobel operator t

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Tsukamoto, Naoko, Yoshihiro Sugaya, and Shinichiro Omachi. "Spectrum Correction Using Modeled Panchromatic Image for Pansharpening." Journal of Imaging 6, no. 4 (2020): 20. http://dx.doi.org/10.3390/jimaging6040020.

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Pansharpening is a method applied for the generation of high-spatial-resolution multi-spectral (MS) images using panchromatic (PAN) and multi-spectral images. A common challenge in pansharpening is to reduce the spectral distortion caused by increasing the resolution. In this paper, we propose a method for reducing the spectral distortion based on the intensity–hue–saturation (IHS) method targeting satellite images. The IHS method improves the resolution of an RGB image by replacing the intensity of the low-resolution RGB image with that of the high-resolution PAN image. The spectral character

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Svystun, Olesya, Ann Wenzel, Lars Schropp, and Rubens Spin-Neto. "Image-stitching artefacts and distortion in CCD-based cephalograms and their association with sensor type and head movement: ex vivo study." Dentomaxillofacial Radiology 49, no. 3 (2020): 20190315. http://dx.doi.org/10.1259/dmfr.20190315.

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Objectives: To assess presence and severity of image-stitching artefacts and distortion in lateral cephalograms acquired by CCD-based sensors and their association with movement. Methods: A human skull was mounted on a robot simulating five head movement types (anteroposterior translation/lifting/nodding/lateral rotation/tremor), at three distances (0.75/1.5/3 mm), based on two patterns (skull returning/not returning to the initial position, except for tremor). Three cephalometric units, two ProMax-2D (Planmeca Oy, Finland), one with Dimax-3 (D-3) and one with Dimax-4 (D-4) sensor, and one Ort

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Wu, Jing, and Xiuqin Su. "Method of Image Quality Improvement for Atmospheric Turbulence Degradation Sequence Based on Graph Laplacian Filter and Nonrigid Registration." Mathematical Problems in Engineering 2018 (July 19, 2018): 1–15. http://dx.doi.org/10.1155/2018/4970907.

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It is challenging to restore a clear image from an atmospheric degraded sequence. The main reason for the image degradation is geometric distortion and blurring caused by turbulence. In this paper, we present a method to eliminate geometric distortion and blur and to recover a single high-quality image from the degraded sequence images. First, we use optical flow technology to register the sequence images, thereby suppressing the geometric deformation of each frame. Next, sequence images are summed by a temporal filter to obtain a single blurred image. Then, the graph Laplacian matrix is used

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Brinded, Philip M. J., John A. Bushnell, Jan M. McKenzie, and J. Elisabeth Wells. "Body-image distortion revisited: Temporal instability of body image distortion in anorexia nervosa." International Journal of Eating Disorders 9, no. 6 (1990): 695–701. http://dx.doi.org/10.1002/1098-108x(199011)9:6<695::aid-eat2260090612>3.0.co;2-e.

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Zhao, Yu, Fan Feng Meng, and Jiang Feng. "Unmanned Aerial Vehicle Based Agricultural Remote Sensing Multispectral Image Processing Methods." Advanced Materials Research 905 (April 2014): 585–88. http://dx.doi.org/10.4028/www.scientific.net/amr.905.585.

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In order to provide more flexibility in remote sensing image collection, unmanned aerial vehicle has been used to kinds of agricultural productions. Images acquired from the UAV based RS system were very useful as a result of their high spatial resolution and low turn-around time. This paper discussed general methods to process the multispectral RS data at image process level. The distortion correction caused by sensor was introduced. The geometric distortion comprised sensor distortion and external distortion caused by external parameters. At last, the general image mosaic methods were discus

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Guo, Yingchun, Gang Yan, Cuihong Xue, and Yang Yu. "Blind Assessment of Wavelet-Compressed Images Based On Subband Statistics of Natural Scenes." International Journal of Advanced Pervasive and Ubiquitous Computing 6, no. 1 (2014): 26–43. http://dx.doi.org/10.4018/ijapuc.2014010103.

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This paper presents a no-reference image quality assessment metric that makes use of the wavelet subband statistics to evaluate the levels of distortions of wavelet-compressed images. The work is based on the fact that for distorted images the correlation coefficients of the adjacent scale subbands change proportionally with respect to the distortion of a compressed image. Subband similarity is used in this work to measure the correlations of the adjacent scale subbands of the same wavelet orientations. The higher the image quality is (i.e., less distortion), the greater the cosine similarity

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Huang, ZunYue, Zhen Luo, SanSan Ao, and YangChuan Cai. "Effect of Laser Welding Parameters on Weld Bowing Distortion of Thin Plates." High Temperature Materials and Processes 37, no. 4 (2018): 299–311. http://dx.doi.org/10.1515/htmp-2016-0153.

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AbstractWeld bowing distortions are detrimental to the assembly process, where laser process parameters such as laser power, welding speed, defocusing distance and gas flow rate play a significant role in determining the weld bowing distortion. Herein, weld bowing distortions in 1-mm-thick AA5052 aluminum were measured by the digital image correlation technique following laser welding. Two mathematical response models were developed to predict the laser weld bowing distortion according to the central composite rotatable design method. The optimized process parameters for minimum bowing distort

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Moon, Cho-I., and Onseok Lee. "Adaptive Fine Distortion Correction Method for Stereo Images of Skin Acquired with a Mobile Phone." Sensors 20, no. 16 (2020): 4492. http://dx.doi.org/10.3390/s20164492.

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With the development of the mobile phone, we can acquire high-resolution images of the skin to observe its detailed features using a mobile camera. We acquire stereo images using a mobile camera to enable a three-dimensional (3D) analysis of the skin surface. However, geometric changes in the observed skin structure caused by the lens distortion of the mobile phone result in a low accuracy of the 3D information extracted through stereo matching. Therefore, our study proposes a Distortion Correction Matrix (DCM) to correct the fine distortion of close-up mobile images, pixel by pixel. We verifi

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Inan, Yucel. "Assesment of the Image Distortion in Using Various Bit Lengths of Steganographic LSB." ITM Web of Conferences 22 (2018): 01026. http://dx.doi.org/10.1051/itmconf/20182201026.

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Several methods developed and applied for protecting the information. One of these is the stenography. Steganographic techniques are used to transmit the information in the image to the receiver in a secure manner. There are two main principles in the steganographic process. The first one is to hide the message in the image and the second one is to reduce the distortion on the image caused by information hiding. By making changes on digital images, a lot of information can be placed in the image. Nevertheless, changes in the image should not be noticed. In this paper, the effect of using vario

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Chen, M., Y. Zhao, T. Fang, Q. Zhu, S. Yan, and F. Gao. "GEOMETRIC AND NON-LINEAR RADIOMETRIC DISTORTION ROBUST MULTIMODAL IMAGE MATCHING VIA EXPLOITING DEEP FEATURE MAPS." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences V-3-2020 (August 3, 2020): 233–40. http://dx.doi.org/10.5194/isprs-annals-v-3-2020-233-2020.

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Abstract. Image matching is a fundamental issue of multimodal images fusion. Most of recent researches only focus on the non-linear radiometric distortion on coarsely registered multimodal images. The global geometric distortion between images should be eliminated based on prior information (e.g. direct geo-referencing information and ground sample distance) before using these methods to find correspondences. However, the prior information is not always available or accurate enough. In this case, users have to select some ground control points manually to do image registration and make the met

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Wang, Qiu Yun. "Depth Estimation Based Underwater Image Enhancement." Advanced Materials Research 926-930 (May 2014): 1704–7. http://dx.doi.org/10.4028/www.scientific.net/amr.926-930.1704.

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According to the image formation model and the nature of underwater images, we find that the effect of the haze and the color distortion seriously pollute the underwater image data, lowing the quality of the underwater images in the visibility and the quality of the data. Hence, aiming to reduce the noise and the haze effect existing in the underwater image and compensate the color distortion, the dark channel prior model is used to enhance the underwater image. We compare the dark channel prior model based image enhancement method to the contrast stretching based method for image enhancement.

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Gao, Farong, Kai Wang, Zhangyi Yang, Yejian Wang, and Qizhong Zhang. "Underwater Image Enhancement Based on Local Contrast Correction and Multi-Scale Fusion." Journal of Marine Science and Engineering 9, no. 2 (2021): 225. http://dx.doi.org/10.3390/jmse9020225.

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In this study, an underwater image enhancement method based on local contrast correction (LCC) and multi-scale fusion is proposed to resolve low contrast and color distortion of underwater images. First, the original image is compensated using the red channel, and the compensated image is processed with a white balance. Second, LCC and image sharpening are carried out to generate two different image versions. Finally, the local contrast corrected images are fused with sharpened images by the multi-scale fusion method. The results show that the proposed method can be applied to water degradatio

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Shen, Peng Fei, Jie Yang, and Yuan Yi Xiong. "Image Defogging Based on Improved Guided Image Filtering." Applied Mechanics and Materials 536-537 (April 2014): 121–26. http://dx.doi.org/10.4028/www.scientific.net/amm.536-537.121.

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In this paper, we analyze the principles of the dark channel prior based on guided filtering image algorithm to defog, pointing out the shortcomings and derive an improved method. Dark channel prior principle is established in the absence of bright areas, which not satisfied Dark channel prior, and thus, the transmittance of the bright areas is estimated error, which will case color distortion of defogged image. By introducing a tolerancemechanism refining the transmittance, the algorithm can effectively handle such problem to overcome the color distortion in bright areas using dark channel pr

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Bao, Jun Wei, Qiang Chen, and Fu Qiang Peng. "Nonlinear Image Mosaic of Pipe Inner Surface." Applied Mechanics and Materials 427-429 (September 2013): 1620–24. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.1620.

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The present study is concerned about image mosaic in single reflector panoramic imaging system (SRPIS). A nonlinear image mosaic algorithm is proposed to get the panoramic image of pipe inner surface. Because of nonlinear distortion in the images which are unwrapped from the original images, its practically impossible for traditional image mosaic method based on 2D planar projective transformation to eliminate phenomenon of ghost and blur in the seam. Nonlinear image mosaic algorithm is performed by projecting many pieces of image divided from right image onto the left image. The position-vari

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Siew, Ronian. "Relative illumination and image distortion." Optical Engineering 56, no. 4 (2017): 049701. http://dx.doi.org/10.1117/1.oe.56.4.049701.

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Xiang, Tianzhu, Gui-Song Xia, and Liangpei Zhang. "IMAGE STITCHING WITH PERSPECTIVE-PRESERVING WARPING." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences III-3 (June 3, 2016): 287–94. http://dx.doi.org/10.5194/isprsannals-iii-3-287-2016.

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Image stitching algorithms often adopt the global transform, such as homography, and work well for planar scenes or parallax free camera motions. However, these conditions are easily violated in practice. With casual camera motions, variable taken views, large depth change, or complex structures, it is a challenging task for stitching these images. The global transform model often provides dreadful stitching results, such as misalignments or projective distortions, especially perspective distortion. To this end, we suggest a perspective-preserving warping for image stitching, which spatially c

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Xiang, Tianzhu, Gui-Song Xia, and Liangpei Zhang. "IMAGE STITCHING WITH PERSPECTIVE-PRESERVING WARPING." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences III-3 (June 3, 2016): 287–94. http://dx.doi.org/10.5194/isprs-annals-iii-3-287-2016.

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Image stitching algorithms often adopt the global transform, such as homography, and work well for planar scenes or parallax free camera motions. However, these conditions are easily violated in practice. With casual camera motions, variable taken views, large depth change, or complex structures, it is a challenging task for stitching these images. The global transform model often provides dreadful stitching results, such as misalignments or projective distortions, especially perspective distortion. To this end, we suggest a perspective-preserving warping for image stitching, which spatially c

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Gao, Guangyong, Caixue Zhou, and Zongmin Cui. "Reversible Watermarking Using Prediction-Error Expansion and Extreme Learning Machine." Mathematical Problems in Engineering 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/670535.

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Currently, the research for reversible watermarking focuses on the decreasing of image distortion. Aiming at this issue, this paper presents an improvement method to lower the embedding distortion based on the prediction-error expansion (PE) technique. Firstly, the extreme learning machine (ELM) with good generalization ability is utilized to enhance the prediction accuracy for image pixel value during the watermarking embedding, and the lower prediction error results in the reduction of image distortion. Moreover, an optimization operation for strengthening the performance of ELM is taken to

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LIN, YUE-DER, HEN-WEI TSAO, and FOK-CHING CHONG. "AN IMAGE PROCESSING ARCHITECTURE TO ENHANCE IMAGE CONTRAST." Biomedical Engineering: Applications, Basis and Communications 14, no. 05 (2002): 215–17. http://dx.doi.org/10.4015/s1016237202000310.

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To have a good image contrast is an important issue in medical images. This paper introduces a feedback-type image processing architecture that can enhance image contrast without further digital image processing technique, e.g. histogram equalization. Compared with the conventional open-loop imaging system, the images derived by the proposed method has a full-range histogram without causing image distortion, and this is difficult to attain for open-loop imaging system.

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Kim, Won Gyum, Yong Seok Seo, Hye Won Jung, Seon Hwa Lee, and Won Geun Oh. "Wavelet Based Multi-Bit Fingerprinting Against Geometric Distortions." Key Engineering Materials 321-323 (October 2006): 1301–5. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1301.

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This paper presents a new image fingerprinting scheme which embeds a multi-bits fingerprinting code and is robust against the geometric attack such as rotation, scaling and translation. We construct a 64 bits fingerprinting code and embed into wavelet subband of 512x512 images repeatedly. In order to restore an image from geometric distortion a noise reduction filter is performed and a rectilinear tiling pattern is used as a template. Results of experimental studies show that our method is robust against geometric distortions and JPEG compression.

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Yakno, Marlina, Junita Mohamad-Saleh, Mohd Zamri Ibrahim, and W. N. A. W. Samsudin. "Camera-projector calibration for near infrared imaging system." Bulletin of Electrical Engineering and Informatics 9, no. 1 (2020): 160–70. http://dx.doi.org/10.11591/eei.v9i1.1697.

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Advanced biomedical engineering technologies are continuously changing the medical practices to improve medical care for patients. Needle insertion navigation during intravenous catheterization process via Near infrared (NIR) and camera-projector is one solution. However, the central point of the problem is the image captured by camera misaligns with the image projected back on the object of interest. This causes the projected image not to be overlaid perfectly in the real-world. In this paper, a camera-projector calibration method is presented. Polynomial algorithm was used to remove the barr

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