Thus, the code length is elevated in accordance with the displacement or norm of motion vector. Information signifying the optimum prediction operate determined as described above is supplied, at the similar time, to the code compressor 7 via line 108b. The code compressor 7 performs compressing transformation so that data is expressed by a minimized variety learn more here of codes by use of knowledge signifying the optimum prediction function, the prediction error sign which is output from the quantizer circuit three when that optimum prediction function is used, and the synchronization sign which becomes necessary at the time of decoding. The transformed signal is then sent out by way of a buffer reminiscence 300 on a line 107 to a transmission line 109 or a storage medium.
In this case, image components in a two-dimensional block throughout a quantity of scanning strains are rearranged, and picture elements in each block are remodeled in order that image components in a single block click here proceed to these in the subsequent block and all image parts in a two-dimensional block are aligned serially. Accordingly, presence of scanning strains need not be of concern when finishing up prediction coding for image elements in a two-dimensional block, and a two-dimensional block could be treated identically to a one-dimensional block produced from M image parts on a single scanning line. As could be seen from the above, when scan conversion is carried out upfront, predictive coding by use of two-dimensional blocks may be no extra than predictive coding by use of one-dimensional blocks. According to the present invention, the above course of is achieved for dedication of the optimum predictive operate by repetitive use of M arithmetic items for N occasions, thus, hardware can be made small when the number of image components M included in a block is small. Moreover, the prediction error energy for a block for every function can be obtained by single computation, permitting the number of an prediction function to be compared subsequent while finishing up the computation. It means that all of N-times computations are not always necessary for determining the optimum prediction perform.
An adaptive coding system learn more here in accordance with declare 2 whereby said prediction operate for dedication of the analysis by said second analysis means is managed in accordance with buffer reminiscence occupancy of the system. 11B shows one example whereby a differential vector signal produces twenty-five vectors on the x-y coordinates, during which digits in circles present the magnitudes, that is, absolutely the values of the vectors. 11A, the pattern of the the length of variable word length code illustrated in connection with the first quadrant is utilized to the remaining quadrants however not depicted for simplicity of illustration. The above patterning of the size of variable word length code is grounded on the next. 4A, parts as designated by 2b, 3, 4, 5 and 6 constitute a typical predictive coder which might schematically be illustrated as shown in FIG. 4B. The provision of the quantizer as shown at dotted line is not essential.
The delay time is dependent on the variety of image parts included within a block. The video sign is equipped from the delay circuit 2a to a subtractor 2b. Here the difference between the picture signal, and the prediction sign provided 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 difference, i.e. the prediction error sign, is then supplied to a quantizer three which capabilities to restrict the variety of potential levels.
5, a sign for scanning line S1 including image elements a11 to a14 is saved in a line reminiscence 1-1 and a signal for scanning line S2 together with a21 to a24 is saved in a line reminiscence 1-2 sequentially. Subsequently, when scanning traces S3 and S4, a31 to a34 and a41 to a44 are saved in line reminiscences 1-3 and 1-4, respectively, line reminiscences 1-1 and 1-2 are learn out within the order of blocks, that's, a11, a12, a21, a22, a13, a14, a23, a24, and so forth. Since studying of scanning lines S1 and S2 in such converted type takes the identical time as that for studying the scanning lines without scan conversion, S1 and S2 may have been learn when the S4 line sign has just been stored in the line reminiscence 1-4. Then, the line recollections 1-3 and 1-4 are read out within the above-mentioned converted kind, whereas succeeding signals for scanning strains S5 and S6 are stored within the line memories 1-1 and 1-2 sequentially.
This value was obtained when the great post to read sampling frequency was eight MHz, in order that info of about zero.8M bits/sec. Was devoted to the motion vector information alone. Accordingly, the place a tv signal is transmitted at a transmission speed of 1.5M bits/sec., the motion vector data would occupy a little greater than 50% of everything of information transmitted. A predictive coding techniques operates based mostly on a principle that a distinction between a sign to be transmitted and a prediction sign is transmitted so as to lower the quantity of transmission info. This invention contemplates an adaptive predictive coding system whereby a plurality of prediction functions that give the prediction indicators are used and an optimum one of many prediction functions is used for performing a prediction coding operation. Thus, the controller 301 receives a signal consultant of the occupancy of the buffer reminiscence 300 via a line a hundred and ten, and designates the quantizer 3, optimum prediction detector 8 and code compressor 7 by way of line 111, and designates the quantizer three, the optimum prediction detector 8, the code compressor 7 and the interpolator 302 through line 112.
The variety of parallel lines for line 215 is decided by the number of image parts included in a block the form of the block, the range of motion compensation and time allowed to find out the optimum prediction function, as in the case of line 106a within the predictive coding apparatus. The reproduced video signal supplied from the interpolator 16 via line 213a is still block-formed and can't be displayed accurately on a typically used monitor and display units.