Analysis of the robustness of wavelet-based perceptual signatures

Perceptual image hashing maps an image to a fixed length binary string based on the image´s appearance to the human eye, and has applications in image indexing, authentication, and watermarking. In this paper, we analyze the robustness of perceptual signatures generated by the known SHA1 hash function in the DWT domain. This is achieved by generation signatures from the coefficients of the subband LL after a DWT transformation. Experiments on large-scale database show that the proposed method is efficient, robust against common content-preserving manipulations.