Thus, the code length is elevated in accordance with the displacement or norm of motion vector. Information signifying the optimum prediction operate decided as described above is supplied, at the identical time, to the code compressor 7 via line 108b. The code compressor 7 performs compressing transformation in order that data is expressed by a minimized variety of codes by use of knowledge signifying the optimum prediction perform, the prediction error sign which is output from the quantizer circuit 3 when that optimum prediction function is used, and the synchronization signal which becomes needed at the time of decoding. The remodeled sign is then sent out by way of a buffer reminiscence 300 on a line 107 to a transmission line 109 or a storage medium.
Generally talking, a operate that makes smallest the prediction error is defined because the optimum perform. Consequently, the movement compensation inter-frame prediction system may be ib888 gaming considered as an adaptive prediction coding system which adaptably determines a most adaptive prediction function among many prediction capabilities.
The transmission path could include conductive wiring traces or a spatial transmission path. In one other method of utilization, a coded video sign is saved once in a storage or a recording medium and thereafter learn out into a decoder as proven in dotted line in FIG. The present system is especially directed to the former scheme.
The delay time depends on the number of image parts included inside a block. The video sign is equipped from the delay circuit 2a to a subtractor 2b. Here the distinction between the image signal, and the prediction sign supplied by way of a line 105a branching from an output line one hundred and five of a prediction signal generator 5, is produced, and the distinction, i.e. the prediction error sign, is then provided to a quantizer 3 which capabilities to restrict the number of attainable levels.
A fixed generator included within the two-dimensional reminiscence 5-1 is preset to similar to the constant generator 8-11d in FIG. eight, and if (0, -1), for instance, is the prediction vector similar to the optimum prediction perform, x3, x4, x14 and x15 are obtained sequentially as the optimum prediction signals on line 105. While outputting the optimum prediction sign, it's essential for ib888 เครดิตฟรี the two-dimensional memory 5-1 to complement the prediction signal generator reminiscence with an area decoding signal supplied by way of line 106a, in order to generate the optimum prediction sign for the subsequent block. The methodology of supplement is identical as that for the prediction signal generator reminiscence 8-11a within the foregoing arithmetic unit. Accordingly, the prediction sign generator 5 is barely expanded for the function of the read control circuit as compared with the arithmetic unit 8-1. In addition, in processing the above-mentioned two-dimensional blocks, it is advantageous that the video sign which has been remodeled for scanning in advance is used.
This value was obtained when the sampling frequency was eight MHz, in order that information of about zero.8M bits/sec. Was devoted to the movement vector info alone. Accordingly, the place a television sign is transmitted at a transmission speed of 1.5M bits/sec., the motion vector information would occupy slightly more than 50% of the whole thing of knowledge transmitted. A predictive coding systems operates based on a principle that a difference between a signal to be transmitted and a prediction sign is transmitted so as to decrease the quantity of transmission data. This invention contemplates an adaptive predictive coding system whereby a plurality of prediction features that give the prediction indicators are used and an optimum one of the prediction features is used for performing a prediction coding operation. Thus, the controller 301 receives a signal consultant of the occupancy of the buffer reminiscence 300 by way of a line 110, and designates the quantizer three, optimum prediction detector 8 and code compressor 7 by way of line 111, and designates the quantizer 3, the optimum prediction detector eight, the code compressor 7 and the interpolator 302 by way of line 112.
If ib888 any computation in two-dimensional block units had been supposed with out use of the scan conversion, the video sign could be scanned within the order of a11, a12, a13, a14, and so on, in FIG. 6, and computation for a two-dimensional block including a11, a12, a21 and a22 must wait for picture parts a21, a22, a23 and a24 on the subsequent scanning line, leading to many blocks whose computations are left suspended till the following line is scanned. More particularly, in a conference TV, the frequency of prevalence of movement vector is the utmost for a movement vector indicative of a standstill image, that is, similar to a inter-frame prediction, and tends to decrease because the norm of movement vector increases. For this purpose, it's potential to efficiently convert an input vector into a variable length code in accordance with the pattern of variable code size as proven in FIG.