lossless jpeg compression

Image compression tool: JPEG imager 2.5.2 If there is reprint, please indicate the source: http://www.cnblogs.com/flydoos/archive/2011/12/26/2301707.html Image compression tool: JPEG imager 2.5.2 The habit of not compressing images when publishing logs. To facilitate the use of a WP plug-in to compress im

A. JPEG compression process JPEG compression is implemented in four steps: 1. Color mode conversion and sampling; 2.DCT transform; 3. Quantification; 4. Code. Two. 1. Color mode conversion and sampling RGB color system is our most common way of representing color. JPEG uses

JPEG compression algorithm steps: Step 1: Convert RGB --> YUV Because of two important features of human vision: Human vision is not sensitive to sharp changes in the edge, human eyes are sensitive to the brightness information of the image, and the color resolution is weak; A large amount of data bit can be used to describe the brightness of an image, and a small amount of information can be used to descri