Abstract: An encoding noise reduction filter is described which is applicable to a decoded video signal produced from a digital video signal encoding and decoding apparatus of a type in which variable values of quantization step size are utilized within each video signal frame and in which orthogonal transform coefficients for respective picture element values are quantized and encoded. Low-amplitude high-frequency components of the decoded video signal are eliminated to achieve encoding noise reduction, with high-frequency emphasis processing of the resultant signal then being applied, and with the operations for eliminating low-amplitude high-frequency components and executing high-frequency emphasis being respectively controlled in accordance with the picture quality of the frame that is currently being processed, as expressed by an average value of quantization step size that was used in encoding processing of the frame.

Abstract: A motion compensated prediction interframe coding system which first measures characteristics regarding the fineness of a pattern or texture of a picture, which is represented by an input television signal and is divided into a group of continuous blocks each quantized by using a quantization step size, and changes the quantization step size into a smaller one if quantizes a block having a picture pattern or texture finer than patterns of the other blocks. Thereby, an amount of generated codes can be limited but a motion compensated prediction frame coding operation can be performed without degrading the fineness of the texture of the original input picture.

Abstract: A motion compensated prediction interframe coding system which includes a first checking portion for judging whether a motion compensation of a coding block is effective and outputting a motion compensation control signal representing the result of the judgement, a storage portion for storing motion vectors of the coding block and adjacent blocks and the motion compensation control signal, a second checking portion for comparing the motion vector of the coding block, of which the motion compensation should be effected, with each of the motion vectors of the adjacent blocks, of which the motion compensation should be effected, and judging that the intra-loop filtering processing to be performed after the motion compensation is ineffective if the number of the adjacent blocks, of which the motion vectors are identical with that of the coding block, is equal to or more than a predetermined number and that the filtering processing performed after the motion compensation is effective in another case, a motion-comp

Abstract: An apparatus for coding a moving-picture signal comprises a first memory temporarily memorizing an input picture signal of one frame. A block of the picture signal, which corresponds to a central portion of the frame, is firstly read out from the first memory and then other blocks of the picture signal are sequentially read out from the first memory in a predetermined order. Each of the blocks of the picture signal has a predetermined number of adjacent pixels. A transform device transforms each block of the picture signal read out from the first memory into transmission information. A second memory stores the transmission information and has a capacity which adaptively varies with a position of the block relative to the frame. A quantizer adaptively quantizes an output from the transform device in accordance with a quantity of the transmission information stored in the second memory and with the position of the block relative to the frame.

Abstract: In a band compression method using an adaptive prediction system preferably applicable to facsimile transmission, a method of selecting picture elements to be referred (hereinafter defined as reference picture elements) for predicting an information value of a picture element wherein the reference picture elements are not selected uniformly and continuously from the neighborhood of the predicted picture element, but a group of picture elements (the first order picture elements) adjacent to the predicted picture element and further a group of picture elements of equal or higher order than the third order are selected as reference picture elements by excluding those shaded picture elements which lie on lines connecting the predicted picture element and the first order picture elements.