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Showing papers on "Inter frame published in 1982"


Journal ArticleDOI
TL;DR: The entropy of prediction errors for two types of adaptive intra-interframe prediction algorithms are measured and a new type of variable length encoding in which the locations of the nonzero prediction errors are coded by horizontal run lengths is discussed.
Abstract: Adaptive prediction schemes provide lower transmission rates than those obtained by simple previous frame prediction. In this paper, we measure the entropy of prediction errors for two types of adaptive intra-interframe prediction algorithms. In the first case, that predictor which results in the least prediction error for previously transmitted neighboring pels is selected from a set of predictor functions. In the second case, prediction is a weighted sum of previous frame and intraframe predictions, where the weights are changed from pel to pel by gradient techniques. We also investigate various modifications of the basic methods. Further, a new type of variable length encoding in which the locations of the nonzero prediction errors are coded by horizontal run lengths is discussed. Compared with the pel entropy of previous frame prediction, the run length coding gives a gain of 2 to 16 percent, depending on the scene. Compared to simple previous frame prediction the first type of adaptive scheme in combination with horizontal run length coding provides a gain in entropy of 18 to 29 percent, whereas the second type of adaptive scheme provides a gain of 20 to 32 percent.

40 citations


Patent
06 Mar 1982
TL;DR: In this article, a non-linear circuit is proposed to suppress quantization noise against an estimated error signal including the quantization signal, and the output value at the area where the input value is large, overshoot or undershoot generated at the moving edge is reduced.
Abstract: PURPOSE:To improve picture quality by providing a non-linear circuit so as to suppress a quantization noise against an estimated error signal including the quantization noise. CONSTITUTION:To a quantization typical value, after weighing according to the value of standard deviation is applied at and average value adding circuit 11, an average value is added and to the result of the addition of the average value, a non-linear process is applied at a non-linear circuit 12. The non-linear circuit 12 consists of, for example, a ROM and converts an input value to the prescribed size of output value according to the input value and to the output, the output of a frame memory 3 is added at an adding circuit 13 and a local decoding signal is generated and it is stored at the frame memory 3 and becomes the next frame estimating signal. By suppressing the output value at an area where the input value of the non-linear circuit 12 is small, an S/N at a still area within a block including a moving edge part is improved. Also by suppressing the output value at the area where the input value is large, overshoot or undershoot generated at the moving edge is reduced.

7 citations


Patent
14 Oct 1982
TL;DR: In this paper, the authors propose to reproduce a video signal of good quality with a small amount of tape consumption by reducing the degree of dependance on the information between frames by comparing the coding system at the recording start moment and that at other time point.
Abstract: PURPOSE:To reproduce a video signal of good quality with a small amount of tape consumption, by reducing the degree of dependance on the information between frames by comparing the coding system at the recording start moment and that at other time point. CONSTITUTION:An analog input signal 1 receives an A/D conversion 2 and a coding 3 to be recorded 4 on a recording medium 5. The signal 1 is then reproduced 8 through a recording medium 7 and decoded 9 to receive a D/A conversion 10. These operations are controlled by a controller 12, and an intraframe coder 21 is selected for the first frame at the starting moment of the recording. Then an interframe coder 20 is selected at and after the following frame. Thus the degree of dependance on the information between frames is reduced. In the reproduction mode, a code is added to a part of the recorded code to discriminate the intraframe coding or the inter-frame coding. This added code is reproduced. And based on the result of this reproduction, an intraframe decoder 31 or an interframe decoder 30 is selected.

5 citations