Image data compression device, compression method, program, and image data decompression device, decompression method, and program

Abstract

A quantizer quantizes ''a prediction error'' as a difference between a pixel X to be compressed and a prediction value X'. A variable-length encoder inputs a quantization number obtained from a quantization table of the quantizer and outputs a variable-length code (compressed code). A prediction value candidate calculation module calculates prediction value candidates (1 to k) according to peripheral pixels A, C, B and transmits them to a multiplexer (MPX). A prediction value decision module decides which of the prediction value candidates (1 to k) is to be a predicted value according to an intermediate value correspondence table based on the image format and an intermediate value / image format correspondence table and transmits a control signal to a multiplexer (MPX). The multiplexer (MPX) outputs one of the decided prediction value candidates (1 to k) as a prediction value X'. Thus, by deciding a prediction value in accordance with the image format, it is possible to reduce the prediction error for each image format.

Description

technical field [0001] The present invention relates to an image data compression device, a compression method, and a program for performing the compression, which are capable of efficiently and high-quality real-time processing of both two types of images (natural images such as movies and CG images such as digital maps) with different characteristics, And an image data restoration device for restoring compressed image data, a restoration method, and a program for performing the restoration. Background technique [0002] In order to transmit image information including a huge amount of information, data compression is required. In particular, in the case of moving images, about 30 to 60 frames of image data are transmitted and received per second, so data compression is indispensable. [0003] However, as image information, natural images represented by video images or movies, etc., and CG images (digital images) represented by maps of car navigation systems, etc. are gene...

AI Technical Summary

Problems solved by technology

[0011] Therefore, as an image data compression device for in-vehicle terminals that processes both natural images and CG images, it is necessary to compress CG images with high quality , and must not degrade the compression efficiency for interlaced images or horizontally long images seen in natural images such as movies

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