Title :
A novel method of lossy image compression for digital image sensors with Bayer color filter arrays
Author :
Xie, Xiang ; Li, GuoLin ; Wang, ZhiHua ; Zhang, Chun ; Li, DongMei ; Li, XiaoWen
Author_Institution :
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Abstract :
Through an analysis of existing compression-first methods, this paper presents a novel method of lossy image compression for digital color image sensors with Bayer color filter arrays (CFAs). In this method, an optimized compression and decompression structure is presented, and the captured CFA raw data is firstly low-pass filtered in RGB space by a smoothing filter followed by the down-sampling operation. Then, the data are transformed from RGB space to YCbCr space. Lastly, the filtered data in YCbCr are compressed directly before full color interpolation that introduces redundancy. The presented method can provide lower compression ratio (bit/pixel) and lower complexity than conventional interpolation-first image compression methods and other existing similar compression-first methods.
Keywords :
image coding; image colour analysis; image sensors; interpolation; low-pass filters; optical filters; signal sampling; smoothing methods; Bayer color filter arrays; CFA; RGB space; YCbCr space; compression ratio; digital color image sensors; down-sampling operation; full color interpolation; lossy image compression; low-pass filtered raw data; optimized compression/decompression structure; quincunx pattern; redundancy; smoothing filter; Digital filters; Digital images; Image analysis; Image coding; Image color analysis; Image sensors; Low pass filters; Optimization methods; Sensor arrays; Smoothing methods; Bayer CFA; lossy image compression; low-pass filter; quincunx pattern;
Conference_Titel :
Circuits and Systems, 2005. ISCAS 2005. IEEE International Symposium on
Print_ISBN :
0-7803-8834-8
DOI :
10.1109/ISCAS.2005.1465755