Color image encryption in non-RGB color spaces

To protect the contents of images in the mobile internet era during image storage and transmission, image encryption has achieved a tremendous success during the last decades. Traditional color image encryption method often use the RGB color space. We have the observation that in non-RGB color spaces, the luminance channels often contain more information for content recognition than the chroma channels do. Thus, in this paper we propose to use high level encryption schemes in more informative channels and low level encryption schemes in less informative channels. The 2D Arnold’s cat map followed by the 3D Lu chaotic map are conducted in the luminance channel. The less complicated DNA coding and 1D logistic map based encryption scheme is leveraged in the chroma channels. We use this strategies in 4 typical non-RGB color spaces, i.e., YCbCr, YIQ, HSV, L*a*b*. We evaluate and compare the performances and the time consumptions of the methods in the 4 Non-RGB color spaces. The experimental results reveal that the encryption methods in Non-RGB color spaces can achieve similar results as the method that conducts the same encryption level in each channel of the RBG color space, including the resistance to several attacks such as brute-force attack, statistic attack, correlation attack, while consuming less time. The method in YCbCr color space performances the best in the time consumption.