Converse quantization and converse frequency converting the code

摘要

PPROBLEM TO BE SOLVED: To improve deterioration in image quality due to quantization error at the time of encoding when a subband encoded code data, e.g. JPEG2000 code data, is decoded. PSOLUTION: A coefficient correction means 14 performs the correction of a subband coefficient decoded by an entropy decoding means 12 for a coefficient dequantized by a dequantization means 13. The coefficient correction means 14 corrects a coefficient having a dequantized value of 0, for example, using the value of its neighboring coefficients. Its correction value is determined by averaging the neighboring coefficients in the same subband as that of a remarked coefficient, or by applying a smoothing filter centering the remarked coefficient. PCOPYRIGHT: (C)2005,JPO&NCIPI