Robust Image Hashing for Image Authentication Based on DCT-DWT Composite Domain

Image hashing function maps an image into a bit string which can be used to authenticate the originality of the image. In this paper, we propose a perceptual image hashing scheme that is secure and robust to visually insignificant changes but fragile enough to detect and precisely locate malicious attacks. The proposed image hashing method is based on the outlines of one-dimensional signals re-arranged from the 8times8 DCT blocks. The final image hash is obtained by applying binary quantization to the DWT coefficients of the obtained 1-D signals. Experimental results are presented to show the effectiveness of the proposed scheme.