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Сжатие видео - Format Conversion

Английские материалы
Авторы Название статьи Описание Рейтинг
Osama K. Alshaykh and Homer H. Chen Minimum-Drift Digital Video Downconversion
Abstract—This paper presents a new technique for decoding a full-resolution video bitstream at low memory cost and displaying the signal at a lower resolution. Existing techniques solve the problem by storing the downconverted blocks into memory instead of the full-resolution blocks. While the memory is reduced, these techniques introduce drift errors because the decoder does not have the same pixels as the encoder in performing motion-compensated prediction. The approach proposed here alleviates the problem by tracking the drift at the decoder. It improves the video quality without any increase in decoder complexity. The effectiveness of the approach is evaluated using both objective and subjective tests. This minimum-drift approach is very simple to implement and can also be applied for memory reduction of a full-resolution HDTV decoder.
RAR  573 кбайт
JЁorg Schwendowius and Gonzalo R. Arce Data-Adaptive Digital Video Format Conversion Algorithms
Abstract—With the emergence of advanced display media as well as digital video coding and compression schemes came a variety of new video formats including program content dependent formats, as proposed by the Grand Alliance for their high definition television (HDTV) standard. Digital video down-conversion is a low complexity quality reduction task, whereas the more complex video up-conversion incorporates a tradeoff between computational cost and perceptual quality. Motion-compensated conversion algorithms have the potential for good results, but go in hand with a computational complexity disadvantage, whereas motion-adaptive interpolation methods constitute a compromise between the extremes. This paper presents a general motionadaptive format conversion approach based on a multiresolution decomposition and nonlinear subband interpolation filtering. The class of L` permutation filters feature a flexible, input-signal dependent behavior by exploiting the order statistics of an input signal. Multiresolution approaches are already successfully applied for image coding and filtering. In this paper, such an approach is utilized for interpolation purposes, applicable to any arbitrary format conversion problem. A successful application of L` filter-based interpolators in combination with a hierarchical multiresolution decomposition as a motion-adaptive format conversion method is presented in this paper. As an evaluation of the performance potential, two format conversion case studies are presented as implementations of the proposed algorithm, namely deinterlacing for progressive display media and frame-rate upconversion for the reduction of temporal artifacts.
RAR  535 кбайт
Erwin B. Bellers, and Gerard de Haan, On Coding Eciency and Scan-Rate Conversion
Abstract: This paper examines the coding e- ciency of MPEG-2 coding for interlaced and pro- gressive video, and also compares de-interlacing and picture rate up-conversion before and after coding. We found receiver side de-interlacing and picture rate up-conversion (i.e. after coding) to give better image quality at a given data rate. In contrast with some other publications, we found in- terlaced video coding to be better than progressive video for many relevant sequences, even when com- paring the results on a progressive display.
RAR  567 кбайт
There are now two generations of ICs for MC video format conversion (MC-VFC) 1. Real-time DSP software for MCVFC has recently been demonstrated, with the breakthroughs enabling this progress coming from motion estimation. The paper gives an overview.
RAR  27 кбайт
R. B. Witterbrood and Haan, Second generation digital signal processor software for video format conversion
RAR  484 кбайт
? E.B. Bellers and G. de Haan On scanning format and MPEG-2 coding efficiency
The traditional analogue video broadcast standard is an interlaced format. Interlace was included in the standards for television broadcasting for very good reasons. However, with the introduction of digital video broadcast (MPEG-2), we should reconsider the use of interlace as part of a digital video chain. Moreover, video format conversion in general, may also require a reconsideration as it can be performed either at the studio end (transmitter side) or at the receiver end (television set). Therefore, this paper examines the coding efficiency of MPEG-2 coding for interlaced and progressive video, and also compares de-interlacing and picture rate up-conversion before and after coding. We found receiver side de-interlacing and picture rate up-conversion, i.e. after coding, to give better image quality at a given data rate. Moreover, and in contrast with some other publications, we found interlaced video coding to be better than progressive video for many relevant sequences, even when comparing the results on a progressive display. We explain how these earlier conclusions could be drawn and why our new conclusions are better.
RAR  93 кбайт
Mark J.W. Mertens and Gerard de Haan Motion vector eld improvement for picture rate conversion with reduced halo
The quality of the interpolated images in picture rate upconversion is predominantly dependent on the accuracy of the motion vector elds. Block based MEs typically yield incorrect vectors in occlusion areas, which leads to an annoying halo in the upconverted video sequences. In the past we have developed a cost-e ective block based motion estimator, the 3D Recursive Search ME, and an improved accuracy version for tackling occlusion, the tritemporal ME. In this article we describe how the vector eld from this tritemporal ME is further improved by a retimer, using information from a foreground/background detector. More accurate motion vector elds are of importance to other applications also (e.g. video compression, 3D, scene analysis...
RAR  765 кбайт
Abstract: The eciency of MPEG-2 coding has been studied for interlaced and progressive video. Also de-interlacing and picture rate up-conversion before and after coding are compared. Receiver side de-interlacing and picture rate up-conversion were found to be superior in terms of resulting im- age quality at a given data rate. In contrast to some other publications, we found coding of inter- laced video superior to coding of progressive video for many relevant sequences, even when comparing the results on a progressive display.
RAR  760 кбайт
The number of video formats is increasing rapidly. As a consequence, the conversion of video signals from one format into another is of growing importance. The motion portrayal of up-converted sequences significantly improves using motion compensated interpolation techniques, but artifacts are generally visible at the boundary of moving objects where either covering or uncovering of picture parts occurs. In this paper, a robust method to locate covered and uncovered areas, find the correct motion vector, and interpolate new pictures, is presented. Moreover, the paper provides an overview and an evaluation of some of the more relevant proposals for picture rate up-conversion.
RAR  133 кбайт
We present an MPEG-2 compatible video codec that uses picture-rate up-conversion during decoding. The upconversion autonomously regenerates major parts of frames without vectorial or residual data. Consequently, the bit rate is greatly reduced.
RAR  56 кбайт
Gerard de Haan* and Jeroen Kettenis** System-on-Silicon for high quality display format conversion and video enhancement
Abstract: A new IC for consumer television applies motion estimation/compensation and directional interpolation for high quality video format conversion. Through motion compensation, the chip realizes judder-free motion portrayal for all sources including 24/25/30Hz (film), and 50/60Hz (video) input material, and many interlaced and progressive display output formats, ranging from 50 to 120 Hz. The true-motion vectors are estimated with a sub-pixel resolution and are used to optimally de- interlace video broadcast signals, to perform a motion compensated picture rate conversion and to improve temporal noise reduction. The most advanced video processing algorithms have been combined on a single die using a 0.18-micron embedded memory CMOS technology.
RAR  3152 кбайт
Meng Zhao*, Jorge A. Leitao*and Gerard de Haan+* Towards an overview of spatial up-conversion techniques
Abstract: The introduction of High definition television (HDTV) asks for spatial up-conversion techniques enabling the display of standard definition material (SDTV). The paper provides an overview of some important linear and non-linear methods. We further include a performance evaluation using a Mean Square Error criterion and show relevant screen shots to allow for a subjective impression obtained with the described algorithms.
RAR  1313 кбайт

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