Multiresolution motion compensation coding for video compression

Motion estimation using block matching algorithm (BMA) is frequently used to reduced the temporal redundancy found in video coding. The performance of the mean squared error (MSE) is usually better than the mean absolute difference (MAD). However, the computational complexity is higher due to the squaring operations. In this paper, we propose a multiple candidates approach to shorten the gap between the two methods with slight increase in computational complexity. Application of the proposed algorithm to subband motion-estimation is studied and simulation results demonstrate that great improvement in performance can be obtained with similar computational complexity as the MAD measure.published_or_final_versio

Visual assessment for the quantization error in wavelet based monochrome videos

The investigation of the discrete wavelet transform (DWT) based video coder is still undergoing in the literature. One of the open problems to be solved is the perception to the quantization noise in different subbands in the DWT domain. This is a critical issue for the development of a better motion compensation (MC) scheme. An experiment and relevant results analysis are presented in this paper to address the above issue. Monochrome video sequences of natural scenes are used in the experiment therefore the so-called masking effects can be taken into account in the decision of the sensitivity to the noise hidden in the DWT domain. The preliminary results show that the most sensitive subbands are those in the lowest three resolution levels under a five-levels decomposition scheme. The further analysis proves that the distribution of the sensitivity to each individual subband has been shifted by the context of the video

Performance of Wavelet-based Multiresolution Motion Estimation for Inbetweeningin Old Animated Films

This  paper  investigates the  performance  of  wavelet-based multiresolution  motion  estimation (MRME)  for  inbetweening  in  old  animated films  using  three different  MRME  schemes.  The  three  schemes  are:  coarse-to fine with a wavelet-based MRME, one of Zhang's MRMEs, and an MRME in the spatial domain.  In order to make a performance comparison of these MRME  schemes,  two  video  sequences were  used  for  a  simulation.  The  experimental results  show  that  the  coarse-to-fine  method  performed  better  than  Zhang's  MRME  and  the  MRME in the spatial domain. The evaluation results  on block size 9x9 indicate that the coarse-to-fine method had an average peak signal-to-noise ratio (PSNR) of  23.48 dB for the first sequence and 29.84 for the second sequence

Block-classified bidirectional motion compensation scheme for wavelet-decomposed digital video

In this paper the authors introduce a block-classified bidirectional motion compensation scheme for the previously developed wavelet-based video codec, where multiresolution motion estimation is performed in the wavelet domain. The frame classification structure described in this paper is similar to that used in the MPEG standard. Specifically, the I-frames are intraframe coded, the P-frames are interpolated from a previous I- or a P-frame, and the B-frames are bidirectional interpolated frames. They apply this frame classification structure to the wavelet domain with variable block sizes and multiresolution representation. They use a symmetric bidirectional scheme for the B-frames and classify the motion blocks as intraframe, compensated either from the preceding or the following frame, or bidirectional (i.e., compensated based on which type yields the minimum energy). They also introduce the concept of F-frames, which are analogous to P-frames but are predicted from the following frame only. This improves the overall quality of the reconstruction in a group of pictures (GOP) but at the expense of extra buffering. They also study the effect of quantization of the I-frames on the reconstruction of a GOP, and they provide intuitive explanation for the results. In addition, the authors study a variety of wavelet filter-banks to be used in a multiresolution motion-compensated hierarchical video codec

Video Coding with Motion-Compensated Lifted Wavelet Transforms

This article explores the efficiency of motion-compensated three-dimensional transform coding, a compression scheme that employs a motion-compensated transform for a group of pictures. We investigate this coding scheme experimentally and theoretically. The practical coding scheme employs in temporal direction a wavelet decomposition with motion-compensated lifting steps. Further, we compare the experimental results to that of a predictive video codec with single-hypothesis motion compensation and comparable computational complexity. The experiments show that the 5/3 wavelet kernel outperforms both the Haar kernel and, in many cases, the reference scheme utilizing single-hypothesis motion-compensated predictive coding. The theoretical investigation models this motion-compensated subband coding scheme for a group of K pictures with a signal model for K motion-compensated pictures that are decorrelated by a linear transform. We utilize the Karhunen-Loeve Transform to obtain theoretical performance bounds at high bit-rates and compare to both optimum intra-frame coding of individual motion-compensated pictures and single-hypothesis motion-compensated predictive coding. The investigation shows that motion-compensated three-dimensional transform coding can outperform predictive coding with single-hypothesis motion compensation by up to 0.5 bits/sample

Video Super Resolution

Note: appendices for this title available here. Advances in digital signal processing technology have created a wide variety of video rendering devices from mobile phones and portable digital assistants to desktop computers and high definition television. This has resulted in wide diversity of video content with spatial and temporal properties fitting into their intended rendering devices. However the sheer ubiquity of video content creation and distribution mechanisms has effectively blurred the classification line resulting in the need for interchangeable rendering of video content across devices of varying spatio-temporal properties. This results in a need for efficient and effective conversion techniques; mostly to increase the resolution (referred to as super resolution) in-order to enhance quality of perception, user satisfaction and overall the utility of the video content