Сжатие видео - Displays Adaptation
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Английские материалы |
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| Авторы | Название статьи | Описание | Рейтинг |
| Soo-Chang Pei, and You-Shen Lo | Color Image Compression and Limited Display Using Self-Organization Kohonen Map |
Abstract—Limited color displays are popular nowadays. Several methods have been proposed to do color quantization for limited color displays. Self-organization of Kohonen feature map (SOFM) is a very useful tool for data clustering. By extracting a special butterfly-jumping sequence from an image, a neural network was fed in that sequence of image data for SOFM training, and a fairly good color table was present to represent that image. The peak signal-to-noise ratio of the decoded image is high (about 35 dB in average for 256 color image), and the perceptual quality is good as well, even with a small set of color table (for example, 32 or 64 colors). Furthermore, the training process is fast. For encoding, we also propose an efficient algorithm based on the Kohonen map ordering property. By considering that the neighboring image pixels are closely related and by setting some acceptable thresholds, we can quickly get an encoded image. For further compressing on the color indexed image with the limited color palette, we cut the indexed images into 4 . 4 blocks and send the block vectors into another SOFM neural network for training. Under the two-dimensional (2-D) mesh neural structure, SOFM vector quantization on an indexed image could largely reduce the color shift artifacts and avoid the requantization problem. About 0.5 b per pixel of coded image can be easily obtained and has a fairly good perceptual quality. More importantly, the decoded color indexed images can be readily displayed. This will reduce the decoder complexity greatly. RAR 476 кбайт |
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| Soo-Chang Pei, Fellow, Ching-Min Cheng, and Lung-Feng Ho | Limited Color Display for Compressed Image and Video |
Abstract—Many display devices nowadays still allow a limited number of colors, called color palette, to be displayed simultaneously. Besides, images and videos in most World Wide Web databases are in compressed formats. Therefore, it becomes an important issue to retrieve a suitable color palette from compressed domain in order to have fast and faithful color reproduction for these devices. In this paper, the color-palette design methods for compressed images and videos are presented. The proposed approaches use the reduced, rather than the whole, image for the color palette design to avoid the heavy computation in image or video decompression. Also, for compressed videos, a shifting-window scheme is proposed to smooth out color variations in the change of color palette. In these methods, we extend the dependent scalar quantization algorithm of a single image to accomplish the color palette design. Experimental results show that output image quality of proposed methods is acceptable to human eyes. In addition, empirical results show that the proposed shifting-window scheme can reduce the main problem of displaying quantized image sequences, screen flicker. RAR 2577 кбайт |
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| M. A. Klompenhouwer and G. de Haan | Optimally Reducing Motion Artifacts in Plasma Displays |
Plasma Display Panels (PDPs) suffer from motion artifacts caused by the subfield driving method. Motion compensation helps to prevent motion blur and dynamic contouring artifacts. Our new algorithm for motion compensation is very regular, inherently avoids rounding errors, and outperforms the earlier methods. RAR 111 кбайт |
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| E.B. Bellers and G. de Haan | TOWARDS AN OPTIMAL TELEVISION DISPLAY FORMAT |
The techniques for video format conversion recently have reached a maturity, where they no longer prohibit application in the consumer domain because of high price or clear picture degradation. Given the resulting new freedom, the question arises how to optimally choose a display format, i.e. free from the television history. In this paper, we present an evaluation of various realistic display formats, all using the same pixel frequency, obtained from a subjective assessment of critical image material originated either for television, or obtained from Internet pages. RAR 47 кбайт |
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| Michiel A. Klompenhouwer and Gerard de Haan | Color Error Diffusion: Accurate Luminance from Coarsely Quantized Displays |
A video signal should use as many bits (gray levels) as possible, to obtain sufficient amplitude resolution for high quality images. However, (digital) displays use a limited number of bits. We propose a modification to the error diffusion algorithm that enables a decrease in the number of bits, without a decrease in luminance accuracy. RAR 305 кбайт |
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| Gerard de Haan and Michiel Klompenhouwer | TEMPORAL ASPECTS OF EMERGING TELEVISION DISPLAYS |
New display principles aim at supreme image quality. The temporal aspects of these devices sometimes remain underexposed, and the paper presents an overview of new artifacts and possible remedies with signal processing. variation, ?t, resulting from the scanning mismatch as a linear function of the position on the screen: RAR 49 кбайт |
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| Erwin B. Bellers, Inge de Weerdy, Gerard de Haany, and Ingrid E.J. Heynderickxy | OPTIMAL TELEVISION SCANNING FORMAT FOR CRT-DISPLAYS |
Current consumer-level priced and state-of-the-art scanrate converters enable a spatio-temporal decoupling of the received video and the displayed video. This paper presents the results of a subjective assessment indicating the preferred CRT-display format. RAR 16 кбайт |
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| Prof. dr. ir. Gerard de Haan | Signal processing for enhanced image representation |
The introduction of digital signal processing in consumer video equipment enabled various techniques to enhance the image representation. This paper provides an overview of techniques developed for high-end television sets in Philips Research Laboratories Eindhoven over roughly the last decade. Three categories of enhancement are distinguished: enhancements required to improve poor input video streams, to repair unfavourable display properties, and to cope with mismatches between source and display format. There will be some emphasis on the enhancements in the last category, as Philips Research took the lead in this area. Also the developments in an important enabling technology, motion estimation, are briefly discussed. RAR 2981 кбайт |
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| Gerard de Haan, Senior Member IEEE and Michiel A. Klompenhouwer | AN OVERVIEW OF FLAWS IN EMERGING TELEVISION DISPLAYS AND REMEDIAL VIDEO PROCESSING |
New display principles aim at supreme image quality. The temporal aspects of these devices sometimes remain underexposed in the literature, and the paper presents an overview of new artifacts and possible remedies with signal processing. RAR 650 кбайт |
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| Erwin B. Bellers, Ingrid E.J. Heynderickxy, Gerard de Haany, and Inge de Weerdy | OPTIMAL TELEVISION SCANNING FORMAT FOR CRT-DISPLAYS |
At the time of introduction of the television, the video format was optimized given both economical and technological constraints. The resulting video format is not necessarily optimal for the current display technology. Moreover, current consumer-level priced and state-of-the-art scan-rate converters enable a spatio-temporal decoupling of the received video and the displayed video. This paper presents the results of a subjective assessment indicating the preferred CRT-display format. RAR 1554 кбайт |
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| Gerard de Haan, and Michiel A. Klompenhouwer | Flaws in emerging displays and remedial video processing |
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| Michiel A. Klompenhouwer and Gerard de Haan | Subpixel Image Scaling for Color Matrix Displays |
The apparent resolution of matrix displays is increased when the relative position of the color subpixels is taken into account. This paper shows that a general method to achieve this for any subpixel arrangement, can be incorporated in an image scaler at low additional cost, allowing simple quality trade-off control. RAR 456 кбайт |
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Подготовили Сергей Гришин и Дмитрий Ватолин