Multi-level image data compression device

TL;DR: In this article, the authors proposed a multi-level image data compression device that selects whether multi-layer image data are binary-compressed after dividing the data into planes or the data of pixels are without plane division depending on a feature of the multilevel image data.

Abstract: PROBLEM TO BE SOLVED: To provide a multi-level image data compression device that selects whether multi-level image data are binary-compressed after dividing the data into planes or the data of pixels are binary-compressed as they are without plane division depending on a feature of the multi-level image data so as to enhance the compression rate. SOLUTION: In the case that multi-level image data received via an image data I/F 7 are subjected to image processing to reduce a medium density, for example, in the case of image data where the correlation among bits in pixels is strong and high level bits and low level bits are majority bits, the bits are not divided and a data selection signal set to '0' is given to selector 9, a compression section 10 applies binary compression to the image data without modifying the form of the image data, and when not, the data selection signal set to '1' is given to the selector 9, and the compression section 10 applies binary compression to the image data after being subjected to bit plane conversion by a bit plane conversion section 8.