亮色分离的饱和图像校正方法  

A Correction Method for Saturated Images Based on Separation of Luminance and Chrominance

作　　者：符均[1] 牟轩沁[1] 季文博[1] 

机构地区：[1]西安交通大学电子与信息工程学院,西安710049

出　　处：《西安交通大学学报》2014年第10期101-107,共7页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(90920003)

摘　　要：针对图像饱和产生的偏色和细节丢失问题,提出了一种在YCbCr色彩空间进行的饱和图像校正方法。在校正时不仅考虑用邻域颜色去校正饱和像素,同时参考了该像素的不饱和通道信息。在单通道饱和像素校正中,设定校正点位于原饱和通道方向的延长线上,且为该线与邻域加权平均颜色组成的直线的最短距离点。由于校正是在YCbCr三维空间进行的,因此校正像素的亮度值被同时固定。在双通道饱和像素校正中,校正点颜色用邻域颜色相关性恢复,亮度值通过参考不饱和通道原始数值计算恢复。在3通道饱和像素校正时,对校正点颜色使用邻域恢复,而对亮度采用了梯度保持的方法。实验结果表明,该方法能更有效地校正RAW格式图像和处理后图像的颜色和亮度,并尽量保持不饱和区域的图像信息。A correction method for saturation images in YCbCr color space is proposed to solve the problem of chrominance distortion and details lost caused by image saturation. Neighborhood＇s chrominances are used to correct the saturated pixel, and the unsaturated channel information of the pixel is used as a reference. The calibration point is located on the extension line of the original saturated straight, and has the shortest distance between the extension line and the line formed from weighted average of its neighborhood＇ s chrominanees, when 1-channel saturated pixels are corrected. Since the correction is performed in the YCbCr three-dimensional color space, the luminance of the corrected pixels can be fixed simultaneously. The chrominance of the saturated pixel is restored by the correlation of neighborhood chrominance, and the luminance of the saturated pixel is restored by computing original values of unsaturated channels, when 2- channel saturated pixels are corrected. The neighborhood recovery method is used to the ehrominance of the saturated pixels, and the gradient maintenance procedure is employed to the luminance of the saturated pixels, when 3-channel saturated pixels are corrected. Experimental results show that the method is more effective in correcting chrominance and luminance of both RAW images and processed images, and maintains the image information of the unsaturated area as much as possible.

关 键 词：饱和校正 色彩校正 亮色分离 彩色图像处理 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]