Showing papers on "Inter frame published in 1981"
TL;DR: The motion compensation is applied for analysis and design of a hybrid coding scheme and the results show a factor of two gain at low bit rates.
Abstract: A new technique for estimating interframe displacement of small blocks with minimum mean square error is presented. An efficient algorithm for searching the direction of displacement has been described. The results of applying the technique to two sets of images are presented which show 8-10 dB improvement in interframe variance reduction due to motion compensation. The motion compensation is applied for analysis and design of a hybrid coding scheme and the results show a factor of two gain at low bit rates.
1,883 citations
01 Apr 1981
TL;DR: A non-adaptive scheme for encoding an image sequence is described that yields better results than any previous comparable interframe image coding method and uses a full image DFT and an optimal quantization algorithm.
Abstract: A non-adaptive scheme for encoding an image sequence is described that yields better results than any previous comparable interframe image coding method. The scheme uses a hybrid of two-dimensional transform coding for the spatial dimension and DPCM for the time dimension similar to some previous works [e.g., 1]. Unlike the previous efforts, which use discrete cosine transforms (DCT's) of image subblocks and suboptimal quantization, we utilize a full image DFT and an optimal quantization algorithm. The results with the standard sixteen frame sequence of Walter Cronkite are visually superior to previous transform coding efforts, especially at rates lower than 1 bit/pixel/ frame. The signal-to-noise ratios are higher than those of nonadaptive hybrid DCT/DPCM in [1] by 2.6 to 10.5 dB depending on rate.
3 citations
TL;DR: It has been shown that the amount of the active picture elements of the proposed method has been reduced to about 50 - 60% of that of the simple frame-to-frame prediction method, and the average log prediction error has been decreased to about50%.
Abstract: An interframe coding system is most promising when a high coding rate is required. However, it is disadvantageous in that the coding rate for the moving picture is not very high. To eliminate this disadvantage, it is effective to compensate for motion displacement. To do this, we propose a method whereby an image is segmented into many blocks. Each block which contains many motion-displaced pixels compared with that of the previous frame, is selected. A motion vector is considered as a shift vector contained in correlated blocks which is detected by calculating the correlation between the preceding frame and the current frame for each block. A simple application of this idea to interframe coding requires a vast amount of calculation, and the realization of the above real-time operation device is difficult. This problem is solved by using a system which modifies sequentially the detected motion displacement in the preceding field, and an experimental device for a motion compensated prediction system is built to test its performance. As a result of an experiment on an actual broadcasted moving image, it has been shown that the amount of the active picture elements of the proposed method has been reduced to about 50 - 60% of that of the simple frame-to-frame prediction method, and the average log prediction error has been decreased to about 50%.
2 citations
07 Dec 1981
TL;DR: In this oa7Der, in order to improve the hybrid system performance, another hybrid optical/digital adaptive IDPCWconditional re plenishment interframe compression architecture is proposed and simulated and reconstructed images with an excellent image quality are obtained.
Abstract: The feasibility of optical processing for interframe image compression has been demon-strated by hybrid optical/digital IDPCM/Frame-to-Frame DPCM interframe compression architecture and its simulation [1]. However, the subjective image quality of the reconstructed 14th frame for 1.5 bits/pixel or 1.75 bits/pixel are not excellent enough to meet a broadcasting standard. Also, the transmission rate performances per second with the frame rate: 30 frames/sec and 256 x 256 lines of the images are 2.9 14bits/sec or 3.4 Abits/sec, resoectively, which are not quite competitive against the 1.5 lbits/sec monochrome videoteleohone system performance [2]. In this oa7Der, in order to improve the hybrid system performance, another hybrid optical/digital adaptive IDPCWconditional re plenishment interframe compression architecture is proposed and simulated. As a result of simulating 14 sequences of Walter Cronkite images with 256 x 25, lines and 6 bit intensity, reconstructed images with an excellent image quality are obtained with 1.2 libits/sec for the frame rate 30 frames/sec, and the average compres-sion ratio performance is 18.13, and the average bit rate is 0.67 bits/pixel.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
1 citations