In this paper, we present a novel image scaling method that employs a mesh model that explicitly represents discontinuities in the image. Our method effectively addresses the problem of preserving the sharpness of edg...
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ISBN:
(纸本)9781538607008
In this paper, we present a novel image scaling method that employs a mesh model that explicitly represents discontinuities in the image. Our method effectively addresses the problem of preserving the sharpness of edges, which has always been a challenge, during image enlargement. We use a constrained Delaunay triangulation to generate the model and an approximating function that is continuous everywhere except across the image edges (i.e., discontinuities). The model is then rasterized using a subdivision-based technique. visual comparisons and quantitative measures show that our method can greatly reduce the blurring artifacts that can arise during image enlargement and produce images that look more pleasant to human observers, compared to the well-known bilinear and bicubic methods.
Most existing 3D image quality metrics use 2D image quality assessment (IQA) models to predict the 3D subjective quality. But in a free viewpoint television (FTV) system, the depth map errors often produce object shif...
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ISBN:
(纸本)9781479902880
Most existing 3D image quality metrics use 2D image quality assessment (IQA) models to predict the 3D subjective quality. But in a free viewpoint television (FTV) system, the depth map errors often produce object shifting or ghost artifacts on the synthesized pictures due to the use of Depth image Based Rendering (DIBR) technique. These artifacts are very different from the ordinary 2D distortions such as blur, Gaussian noise, and compression errors. We thus propose a new 3D quality metric to evaluate the quality of stereo images that may contain artifacts introduced by the rendering process due to depth map errors. We first eliminate the consistent pixel shifts inside an object before the usual 2D metric is applied. The experimental results show that the proposed method enhances the correlation of the objective quality score to the 3D subjective scores.
Impulse noise is commonly encountered during image transmission and many methods have been proposed to remove it. Although it is now possible to recover the true image reasonably well, even under severe noise (90% pix...
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ISBN:
(纸本)9781479961399
Impulse noise is commonly encountered during image transmission and many methods have been proposed to remove it. Although it is now possible to recover the true image reasonably well, even under severe noise (90% pixel contamination), essentially all methods published so far follow the standard procedure of noisy pixel detection/classification and then noisy pixel value reconstruction, without any further processing. In this paper we show an interesting empirical discovery that the traditionally denoised image tends to have the estimation error with a Laplacian distribution, which makes it possible to add a postprocessing stage to denoise the traditionally obtained result with this new type of noise. We propose a practical algorithm within this new framework and experimental results show that superior results can be obtained over previously published methods.
A framework integrating distributed vision nodes within a transmission control protocol/Internet protocol (TCP/IP) based, anonymous communication environment is introduced. The main system capabilities are central con...
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A framework integrating distributed vision nodes within a transmission control protocol/Internet protocol (TCP/IP) based, anonymous communication environment is introduced. The main system capabilities are central configurability and maintainability of the imageprocessing nodes and the scalability of the framework. Furthermore a watchdog concept and IEC61131 conform signal integration comprising the Modbus/TCP protocol are integrated within the framework. A communication structure based on the tuplespace concept is presented. The possibility of integrating heterogeneous nodes is achieved by a consistent Java(TM) implementation. As a proof of concept, a quality observation task at distributed observation points at a wire rolling mill is introduced. An image-processing algorithm based on least-squares fitting of parallel lines to observe quality relevant parameters is introduced and integrated as an exemplary machine vision implementation within the framework. (C) 2004 SPIE and IST.
In this work we apply techniques originating from classical fractal still-image coding to block-matching motion compensation algorithms for digital video compression. Especially the method of adapting the gray-values ...
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ISBN:
(纸本)0819427497
In this work we apply techniques originating from classical fractal still-image coding to block-matching motion compensation algorithms for digital video compression. Especially the method of adapting the gray-values in image blocks of the current frame to those in blocks of the reference-frame shows promising performance.
imageprocessing and analyzing images of the operation is to always ask about their quality, whether the quality is increased or decreased? image Quality Assessment techniques is required for prediction of quality of ...
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ISBN:
(纸本)9781479933587
imageprocessing and analyzing images of the operation is to always ask about their quality, whether the quality is increased or decreased? image Quality Assessment techniques is required for prediction of quality of the image. Human visual System (HVS) has been widely incorporated in estimating the quality of the image, as human is the ultimate observer of the image. In this work, Author investigated the SSIM index depends upon correlation based filtering like Gaussian low pass filter, averaging filter, Circular averaging filter and motion filter, also mean square error and peak signal to noise ratio is used.
This paper presents an energy efficient VLSI architecture for motion estimation using imageprocessing assisted voltage overscaling (VOS). Motion estimation is the most computationally expensive block inside any video...
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ISBN:
(纸本)9780819469946
This paper presents an energy efficient VLSI architecture for motion estimation using imageprocessing assisted voltage overscaling (VOS). Motion estimation is the most computationally expensive block inside any video encoder, typically consuming 40-60% of the total power. This work focuses on using VOS to reduce power consumption at the expense of marginal loss of visual quality. Some imageprocessing techniques are used to assist VOS so that a better trade-off between power and visual quality can be achieved. The design is demonstrated using full search and three step search algorithms. Simulation results in 65mn CMOS technology show that the proposed technique can save up to 30% power at the cost of 0.5dB loss of PSNR.
We proposed in this paper a retina model based approach for image quality assessment. The retinal model is consisted of an optical modulation transfer module and an adaptive low-pass filtering module. We treat the mod...
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ISBN:
(纸本)9781479902880
We proposed in this paper a retina model based approach for image quality assessment. The retinal model is consisted of an optical modulation transfer module and an adaptive low-pass filtering module. We treat the model as a black box and design the adaptive filer using an information theoretical approach. Since the information rate of visual signals is far beyond the processing power of the human visual system, there must be an effective data reduction stage in human visual brain. Therefore, the underlying assumption for the retina model is that the retina reduces the data amount of the visual scene while retaining as much useful information as possible. For full reference image quality assessment, the original and distorted images pass through the retinal filter before some kind of distance is calculated between the images. Retina filtering can serve as a general preprocessing stage for most existing image quality metrics. We show in this paper that retina model based MSE/PSNR, though being straightforward, has already state of the art performance on several image quality databases.
Correct assessment of image fidelity is fundamental to the development of efficient image compression schemes especially to that of the schemes taking characteristics of the human visual system into account. In this p...
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ISBN:
(纸本)9781424412501
Correct assessment of image fidelity is fundamental to the development of efficient image compression schemes especially to that of the schemes taking characteristics of the human visual system into account. In this paper, a fidelity metric for assessing the visual quality of color images is presented. The proposed fidelity metric is designed to measure the perceivable distortion in the quasi-uniform color space of CIELAB. To evaluate the perceptibility of distortion, a color visual model is employed to estimate the visibility threshold of distortion for each color pixel. The visibility threshold of each color is measured as the size of the sphere of just-noticeable color difference and is modeled as a function of chroma, local luminance gradient and background uniformity. Simulation results show that the assessment of the proposed fidelity metric is more correspondent with the subjective assessment than other metrics using PSNR and CIELAB Delta E.
The demand for human face enhancement in pictures is increasing. This paper describes an effort to utilize state-of-the-art signal processing technologies for the enhancement of the human face in pictures. First, seve...
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ISBN:
(纸本)9781479961399
The demand for human face enhancement in pictures is increasing. This paper describes an effort to utilize state-of-the-art signal processing technologies for the enhancement of the human face in pictures. First, several non-linear filters are examined, and it is demonstrated that the total variation regularization filter (TV filter) shows the remarkably best effect for skin smoothing including the removal of wrinkles, stains, moles, and freckles. The reason is analyzed in detail. Then, super-resolution technology is utilized to enhance the image quality for specific parts of the face, such as the eye line, pupil, eyelashes, and hair. Facial part extraction technology is also utilized for the enhancement of selected face parts. Interestingly, we found that the super-resolution technology not only improves the clarity of the image but also increases the brilliancy in the pupil and hair. The super-resolution technology used in this paper is based on the non-linear filtering method developed for 4K high-definition television.
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