1D Frequency Transformation- Based Amplitude- Only Images for Copyright- and Privacy- Protection in Image Trading Systems

This paper proposes an effective method of generating amplitude-only images (AOIs) which are inversely transformed amplitude components of images and which are used in the copyright- and privacyprotected digital fingerprinting-based image trading systems. The proposed method applies a one-dimensional frequency transformation to an image for generating the AOI with low intensity range (IR), whereas the IR of the AOI in the conventional method using a two-dimensional transformation is too large to store or transmit. The proposed method is distinct from other IR reduction approaches such as clipping, linear and non-linear scaling, block division, and random sign assignment which require extra-calculations, it reduces the computational complexity while it reduces IRs of AOIs. Moreover, experimental results show that the proposed method enhances the quality of fingerprinted images and fingerprinting performance.