Program image data restoration device and program image data compression apparatus, and compression method, and how to restore

摘要

Quantizer is to quantize the "prediction error" is the difference value of the predicted value X 'and compression target pixel X. As an input a quantization number obtained from the quantization table of the quantizer, a variable length encoder outputs the variable-length code (compressed code). Predicted value candidate calculation module sends a multiplexer (MPX) to calculate the predicted value candidate 1~k based peripheral pixels A, C, and B. Then determined based on the intermediate value and the image format correspondence table and intermediate values ​​correspondence table according to the image format whether to predicted value which of the predicted value candidate 1~k, predicted value determination module, a multiplexer (the control signal I want to send to the MPX). The multiplexer (MPX) outputs as a prediction value X 'to either of the predicted value candidate 1~k determined. By selectively using prediction value according to the image format in this way, it becomes possible to reduce the prediction error for each image format.