VORRICHTUNG ZUR KOMPRESSION VON BILDDATEN MIT FARBEMPFINDLICHER QUANTISIERUNG

摘要

In a picture data compressing device, picture data is divided by a blocking circuit (1) into plural blocks each consisting of a pre-set number of pixels and shuffled by a shuffling circuit (2). The blocked and shuffled data is transformed by a DCT circuit (3) into data in the frequency domain and re-quantized by a quantization circuit (4) for compressing the picture data. A red detector (6) decides whether or not a block from the shuffling circuit (2) is a red-based block. If the red detector (6) finds the block to be a red-based block, a controller (7) controls the quantization circuit (4) so that the quantization step of the quantization circuit (4) will become finer. The picture data of the red-based block susceptible to block distortion may be quantized with a finer quantization step for improving reproducibility and alleviating block distortion. <IMAGE>