Phase Scrambling for Image Matching in the Scrambled Domain
Hitoshi Kiya, Izumi Ito · Signal Processing · 2010
The presented scrambling enables image matching using invisible images. In addition, image matching between phase-scrambled images is performed with the same accuracy as that between non-scrambled images. We have explained how to generate phase-scrambled signals that protect the information in the original image and demonstrated that the presented synchronized phase-scrambling maintains the relative relationship between two signals mathematically. We have shown that the presented scrambling is applicable to both DFT and DCT coefficients, and therefore secure image matching for phase-based correlation is achieved. In particular, DCT-SPC is closely related to the image compression method. Application of the presented scrambling in areas such as image communications and image compression appears promising. In the presented scrambling, the management of keys depends on desired systems. Meanwhile, for visual protection, there is one-time key based phase scrambling which does not require the management of keys (26; 27).