Therefore, the reproduced image signal is remodeled by the scan inverter circuit 14 again to the video signal in original time sequence, then the decoded video signal is shipped out on line 214. 10 is a block diagram showing an embodiment of the predictive decoding system in accordance with the current invention. In the figure, the video sign which has imp source been coded by prediction by the use of the predictive coding system of FIG.
Preferably, the motion vector info is coded right into a variable word length code which has the minimal code size for the inter-frame prediction. Specifically, the code size of the variable word length code is minimal for the inter-frame prediction and increases as the norm of the motion vector will increase. In the previous, a relatively excessive transmission speed was assumed in order that it has been considered that the share of the motion vector information is negligibly small. Consequently, it has been thought of that an optimum prediction which minimizes the quantity of the entirety of knowledge transmitted may be realized by detecting a movement vector which minimizes the quantity of knowledge representing a have a peek at these guys prediction error.
The expanded and separated data representing the optimum prediction operate and prediction error signal are provided to a prediction sign generator 12 and an adder thirteen through traces and 211-1, respectively. The prediction signal generator 12 generates the optimum prediction sign in accordance with information representing the optimum prediction function, and the perform and structure of the generator are the identical as those of the prediction sign generator 5 in the predictive coding system. The generated prediction signal is provided through line 212 to the adder thirteen and added to the prediction error sign equipped by way of line 211-1, so that a video sign is reproduced. The reproduced video signal is then supplied to a scan inverter circuit 14 and a delay circuit 15 by way of an interpolator 16 and contours 213a and 213b branching from line 213. The interpolator sixteen connected to the code expander eleven by way of a line 216 matches the interpolator 302 as shown in FIG.
On the opposite hand, after scan conversion has been carried out, the video sign is arranged within the order of a11, a12, a21, a22, a13, a14, a23, a24 and so on, and computation for a two-dimensional block takes solely four picture component durations corresponding to for a11, a12, a21 or for a13, a14, a23 and a24, and usually M image factor periods. When scan conversion is carried out in advance, computation for each two-dimensional block turns into the identical as that for a one-dimensional block including, for example, a11, a12, a13, and a14, thus greatly simplifying the computation management. Thus, prediction at a location shifted by -Vx in the x-direction and -Vy within the y-direction from a corresponding point within the previous body minimizes and optimizes the prediction error energy P. Therefore, the prediction function expressed by use of the vector (-Vx, -Vy) is the optimum prediction perform, and is referred to herein because the motion vector. As described above, when a movement vector is decided in accordance with both movement vector data and prediction error data, the efficienty of coding could be remarkably improved particularly the place the transmission velocity is low. Accordingly, the invention is very effective the place a television sign undergoes compressive coding and is transmitted at a low speed.
A constant generator included within the two-dimensional memory 5-1 is preset to similar to the fixed generator 8-11d in FIG. 8, and if (0, -1), for instance, is the prediction vector corresponding to the optimum prediction function, x3, x4, x14 and x15 are obtained sequentially because the optimum prediction signals on line a hundred and five. While outputting the optimum prediction signal, it is necessary for the two-dimensional memory 5-1 to complement the prediction sign generator reminiscence with a neighborhood decoding sign provided via line 106a, in order to generate the optimum prediction sign for the next block. The method of complement is identical as that for the prediction signal generator reminiscence 8-11a in the foregoing arithmetic unit. Accordingly, the prediction sign generator 5 is barely expanded for the function of the learn control circuit as in contrast with the arithmetic unit 8-1. In addition, in processing the above-mentioned two-dimensional blocks, it's advantageous that the video signal which has been reworked for scanning prematurely is used.
This worth was obtained when the sampling frequency was 8 MHz, in order that data of about zero.8M bits/sec. Was devoted to the motion vector data alone. Accordingly, where a tv signal is transmitted at a transmission pace of 1.5M bits/sec., the movement vector information would occupy somewhat greater than 50% of the whole thing of knowledge transmitted. A predictive coding techniques operates primarily based on a precept that a difference between a sign to be transmitted and a prediction sign is transmitted so as to decrease the quantity of transmission information. This invention contemplates an adaptive predictive coding system whereby a plurality of prediction capabilities that give the prediction signals are used and an optimum one of the prediction capabilities is used check my blog for performing a prediction coding operation. Thus, the controller 301 receives a signal representative of the occupancy of the buffer memory 300 by way of a line a hundred and ten, and designates the quantizer 3, optimum prediction detector eight and code compressor 7 via 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 components included in a block the shape of the block, the range of movement compensation and time allowed to discover out the optimum prediction function, as within the case of line 106a within the predictive coding apparatus. The reproduced video signal supplied from the interpolator sixteen via line 213a continues to be block-formed and cannot be displayed appropriately on a usually used monitor and display units.