Colorization in YCbCr Space and its Application to Improve Quality of JPEG Color Images

This paper presents a colorization method in YCbCr color space, which is based on the maximum a posteriori estimation of a color image given a monochrome image as is our previous method in RGB color space. The presented method in YCbCr space is much simpler than that in RGB space and requires much less computation time, while both methods in YCbCr and RGB space produce color images with comparable PSNR values. The proposed colorization in YCbCr is applied to JPEG compressed color images aiming at better recovery of down sampled chrominance planes. Experimental results show that colorization in YCbCr is usually effective for quality improvement of JPEG color images.