A New Color Digital Image Scrambling Algorithm Based on Chaotic Sequence

In order to protect color digital image's information, a new scrambling algorithm based on chaotic sequence is proposed. Firstly, according to the key and the size of color digital image m×n, a chaotic sequence with length of 3mn is generated, and a corresponding subscript sequence is generated by sorting it. Then, the image's RGB component is combined to a matrix of pixels, and transforming of pixel coordinates based on the subscript sequence will be realized. Lastly, the scrambling matrix of pixels is decomposed into RGB component, and the scrambling image is generated. The effect of scrambling and security is also analyzed by using the evaluation index. Theoretical analysis and experimental results show that the algorithm has a large space of key, a good scrambling effect, statistical characteristics and security, a strong against damaging and painting ability.