Results of denoising based on discrete cosine transform for a wide class of images corrupted by additive noise are obtained. Three types of noise are analyzed: additive white Gaussian noise and additive spatially corr...
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ISBN:
(纸本)9781628414899
Results of denoising based on discrete cosine transform for a wide class of images corrupted by additive noise are obtained. Three types of noise are analyzed: additive white Gaussian noise and additive spatially correlated Gaussian noise with middle and high correlation levels. TID2013 image database and some additional images are taken as test images. Conventional DCT filter and BM3D are used as denoising techniques. Denoising efficiency is described by PSNR and PSNR-HvS-M metrics. Within hard-thresholding denoising mechanism, DCT-spectrum coefficient statistics are used to characterize images and, subsequently, denoising efficiency for them. Results of denoising efficiency are fitted for such statistics and efficient approximations are obtained. It is shown that the obtained approximations provide high accuracy of prediction of denoising efficiency.
Machine vision has become a key technology in the area of quality control. "vision systems" is primarily focused on computer vision in the context of inspection of the products such as food, pharmaceuticals....
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ISBN:
(纸本)9781479968053
Machine vision has become a key technology in the area of quality control. "vision systems" is primarily focused on computer vision in the context of inspection of the products such as food, pharmaceuticals. The system can consist of a number of cameras all capturing, interpreting and signaling individually with a control system related to some predefined algorithms. The analysis of citrus fruits using various assorted parameters revealing the diseases afflicting Citrus fruits and isolation of the same using imageprocessing and Data Mining Techniques is the core area discussed here with.
This paper considers models and algorithms of normalization of images obtained from geostationary remote sensing systems. And the paper suggests and researches algorithms of geometrical distortion correction and trans...
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This paper considers models and algorithms of normalization of images obtained from geostationary remote sensing systems. And the paper suggests and researches algorithms of geometrical distortion correction and transformation of images into the standard Normalized Geostationary Projection. The algorithm of geodetic connection adjustment with usage of Earth contour points in the image was developed. Practical testing of algorithms in the images obtained from the Russian spacecraft "Elektro-L" was executed.
Synthetic Aperture Radars (SAR) provide high resolution ground images by utilizing the aircraft motion to synthesize a large aperture. The presence of residual phase error in the SAR images causes defocusing in the im...
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ISBN:
(纸本)9781509007752
Synthetic Aperture Radars (SAR) provide high resolution ground images by utilizing the aircraft motion to synthesize a large aperture. The presence of residual phase error in the SAR images causes defocusing in the images. Autofocus algorithm compensates these phase errors to obtain a focused image. In most scenarios a priori information about the type of phase error is known which can be effectively utilized in autofocus techniques. The paper proposes a new autofocus algorithm which is based on Wiener filter theory and implements a multistage Wiener filter to compensate the phase error in SAR images.
Epiretinal prosthesis is a biomedical implant technology currently being developed around the world in hopes of restoring useful vision for patients suffering from retinal degenerative diseases such as Age-related Mac...
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ISBN:
(纸本)9781467391986
Epiretinal prosthesis is a biomedical implant technology currently being developed around the world in hopes of restoring useful vision for patients suffering from retinal degenerative diseases such as Age-related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP). Epiretinal Prosthesis System (EPS) consists of four parts that includes Body Worn image Processor (BWIP), Retinal Implantable Receiver Stimulator (RIRS), wireless telemetry and electrode array. images are captured by BWIP's camera and encoded into a 1 Mbps bit stream by BWIP. The bit stream is modulated on 8.195 MHz carrier and transmitted serially to RIRS through wireless telemetry. RIRS converts the bit stream into electrical pulses and drives 1024 electrode array to stimulate the survival parts of retina electrically with visual cues for understanding the video picture/image. This paper presents the design of flexible high resolution 1024- electrode embedded computer based EPS using embedded computer based efficient control algorithms for better visual prediction. Finally, the integrity of the EPS has been verified visually through video display on LCD/LED array. The experimental results of EPS are enumerated for the object of human face using 1024-electrode/pixel LED array.
This paper describes a novel approach for extraction of multiple objects from a given image of a natural scene. In the proposed approach, multiple objects are extracted by the application of saliency detection on the ...
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ISBN:
(纸本)9781479918232
This paper describes a novel approach for extraction of multiple objects from a given image of a natural scene. In the proposed approach, multiple objects are extracted by the application of saliency detection on the image. We use two distinct approaches for object extraction. One approach uses superpixels on the saliency map. Then the intensity of saliency map in each superpixel is used to compute distance between the centres of superpixels. These act as constraints to extract the objects from the image. The other approach is the application of Active Contour model on the saliency map and estimating a bounding box on the intermediate binary image result extracts the objects in the image. The approach is unique in its way of extracting objects from a scene containing multiple objects as it does not use extensive image search like the existing algorithms and therefore leads to a fast and simple extraction.
A pressure ulcer is a clinical pathology of localized damage to the skin and underlying tissue caused by pressure, shear or friction. Diagnosis, care and treatment of pressure ulcers can result in extremely expensive ...
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A pressure ulcer is a clinical pathology of localized damage to the skin and underlying tissue caused by pressure, shear or friction. Diagnosis, care and treatment of pressure ulcers can result in extremely expensive costs for health systems. A reliable diagnosis supported by precise wound evaluation is crucial in order to succeed on the treatment decision and, in some cases, to save the patient's life. However, current clinical evaluation procedures, focused mainly on visual inspection, do not seem to be accurate enough to accomplish this important task. This paper presents a computer-vision approach based on imageprocessingalgorithms and supervised learning techniques to help detect and classify wound tissue types that play an important role in wound diagnosis. The system proposed involves the use of the k-means clustering algorithm for image segmentation and compares three different machine learning approaches neural networks, support vector machines and random forest decision trees to classify effectively each segmented region as the appropriate tissue type. Feature selection based on a wrapper approach with recursive feature elimination is shown to be effective in keeping the efficacy of the classifiers up and significantly reducing the number of necessary predictors. Results obtained show high performance rates from classifiers based on fitted neural networks, random forest models and support vector machines (overall accuracy on a testing set [95% Cl], respectively: 81.87% [80.03%, 83.61%];87.37% [85.76%, 88.86%];88.08% [86.51%, 89.53%]), with significant differences found between the three machine learning approaches. This study seeks to provide, using standard classification algorithms, a consistent and robust methodological framework as a basis for the development of reliable computational systems to support ulcer diagnosis. (C) 2015 Elsevier B.v. All rights reserved.
visual place recognition has been vastly researched in the last decade. Most of the previous works have concentrated on improvement of performance when the environment changes due to illumination, weather or season at...
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ISBN:
(纸本)9781467390583
visual place recognition has been vastly researched in the last decade. Most of the previous works have concentrated on improvement of performance when the environment changes due to illumination, weather or season at outdoor with abundant features and textures for place recognition. On the other hand, when a robot moves in a home environment, input images sometimes contain less features or textures for place recognition, which in turn degrades the precision and recall performance. This paper presents an efficient place recognition method based on a binary robust independent elementary features gist (BRIEF-Gist) descriptor for indoor home service robot. The proposed method simply extracts multiple BRIEF-Gist descriptors from an input image, which results in a higher performance. A simple data structure for fast comparison between images is also presented. In home environment experiments, the original BRIEF-Gist and the proposed method shows the maximum recall rate of 1.6% and 9.7%, respectively, both with a precision of 100%. On the other hand, local feature based DLoopDetector method shows below 5% of both recall and precision performance. For comparison, computation times, which are the average execution times for processing place recognition algorithms of one image with 2058 places in a map, are measured;the proposed method without the proposed data structure takes 31.4 ms, and the proposed method with the proposed data structure takes 10.5 ms.
Mammographic Computer-Aided Diagnosis systems are applications designed to assist radiologists in diagnosis of malignancy in mammographic findings. Most methods described in the literature do not perform a proper prep...
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ISBN:
(纸本)9781509035694;9781509035687
Mammographic Computer-Aided Diagnosis systems are applications designed to assist radiologists in diagnosis of malignancy in mammographic findings. Most methods described in the literature do not perform a proper preprocessing step in mammographic images prior to classification, which can generate inconsistent results due to the potentially large amount of noise in medical images. This paper proposes a new method based on Information Theory and Data Compression for detection of random noise in image bit planes. In order to validate the efficiency of the proposed noise removal method, we used Machine Learning algorithms to classify mammographic findings from the Digital Database for Screening Mammography. Results using texture features indicate that a reduction in the radiometric resolution of 4 or 5 bit planes in digitized screen film mammographic images result in a better classification performance.
Recent advances in high dynamic range (HDR) capture and display technologies have attracted a lot of interest from scientific, professional, and artistic communities. As in any technology, the evaluation of HDR system...
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Recent advances in high dynamic range (HDR) capture and display technologies have attracted a lot of interest from scientific, professional, and artistic communities. As in any technology, the evaluation of HDR systems in terms of quality of experience is essential. Subjective evaluations are time consuming and expensive, and thus objective quality assessment tools are needed as well. In this paper, we report and analyze the results of an extensive benchmarking of objective quality metrics for HDR image quality assessment. In total, 35 objective metrics were benchmarked on a database of 20 HDR contents encoded with 3 compression algorithms at 4 bit rates, leading to a total of 240 compressed HDR images, using subjective quality scores as ground truth. Performance indexes were computed to assess the accuracy, monotonicity, and consistency of the metric estimation of subjective scores. Statistical analysis was performed on the performance indexes to discriminate small differences between metrics. Results demonstrated that metrics designed for HDR content, i.e., HDR-vDP-2 and HDR-vQM, are the most reliable predictors of perceived quality. Finally, our findings suggested that the performance of most full-reference metrics can be improved by considering non-linearities of the human visual system, while further efforts are necessary to improve performance of no-reference quality metrics for HDR content.
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