Decoding a block of quantized transform coefficients, wherein an even parity of the sum of the inversely quantized transform coefficients is set to an odd parity

DISADAPTATION ERROR OCCURS IN LOCAL DECODER OF A STANDARD MPEG COMPRESSOR FOR A MOVING PICTURE SIGNAL, AND OF A STANDARD MPEG EXPANDER FOR A COMPRESSED MOVING PICTURE SIGNAL. THIS IS BECAUSE OF THE LACK OF A STANDARD FOR ROUNDING RESULTS OF *, 5 (* IT IS AN INTEGER) OBTAINED WHEN A GROUP OF TRANSFORMATION COEFFICIENTS THAT RESULT FROM COMPRESSING THE MOVING IMAGE SIGNAL ARE INVERSONALLY ORTOGONALLY TRANSFORMED. THE INVENTION AVOIDS MISADEMANTATION ERRORS BY PREPROCESSING THE GROUP OF TRANSFORMATION COEFFICIENTS BEFORE TRANSFORMATION (15) REVERSE ORTHOGONAL. THE TRANSFORMATION COEFFICIENTS OF THE GROUP ARE SUM (23A) AND THE PARITY (ODD OR EVEN) OF THE SUM IS JUDGED (21). WHEN PARITY IS DECIDED TO BE PAR, THE PARITY OF ONE OF THE GROUP'S TRANSFORMATION COEFFICIENTS IS INVERTED (28) TO PROVIDE AN INVERTED PARITY TRANSFORMATION COEFFICIENT. THIS MAKES THE PARITY OF THE ODD SUM. THEN, WHEN THE GROUP OF TRANSFORMATION COEFFICIENTS INCLUDING INVERTED PARITY TRANSFORMATION COEFFICIENTS ARE TRANSFORMED (15) ORTOGONALLY INVERSONLY, NONE OF THE RESULTS OF ORTHOGONAL TRANSFORMATION WILL HAVE A VALUE OF *, 5.