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METHODS AND DEVICES FOR PROCESSING OF TRANSFORM COEFFICIENTS, METHODS AND DEVICES FOR REVERSE ORTHOGONAL TRANSFORM OF TRANSFORM COEFFICIENTS, METHODS AND DEVICES FOR COMPRESSION AND EXPANDING OF MOVING IMAGE SIGNAL, RECORD MEDIUM FOR COMPRESSED SIGNAL WHICH REPRESENTS MOVING IMAGE
METHODS AND DEVICES FOR PROCESSING OF TRANSFORM COEFFICIENTS, METHODS AND DEVICES FOR REVERSE ORTHOGONAL TRANSFORM OF TRANSFORM COEFFICIENTS, METHODS AND DEVICES FOR COMPRESSION AND EXPANDING OF MOVING IMAGE SIGNAL, RECORD MEDIUM FOR COMPRESSED SIGNAL WHICH REPRESENTS MOVING IMAGE
FIELD: digital signal processing. SUBSTANCE: local decoders of MPEG compression controllers generate rounding-off errors caused by lack of standard for rounding off such results as *.5, where *. is integer. Such errors appear when set of transform coefficients which are generated by compression, is subjected to reverse orthogonal transform. Described method involves preliminary processing of transform coefficients before their reverse orthogonal transform by means of addition of transform coefficients in set, evaluation of control sum parity. If control sum is even, parity of one of transform coefficients in set is inverted in order to achieve transform coefficient with inverted parity. Then, if set of transform coefficients including transform coefficient with inverted parity is subjected to reverse orthogonal transform, any orthogonal transform coefficient is not equal to *.5. EFFECT: prevention of rounding errors. 50 cl, 30 dwg
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