An Error-Detecting Code Based Fragile Watermarking Scheme in Spherical Coordinate System

In this paper, an error-detecting code based public fragile watermarking scheme that enables the authentication of 3D models for detecting unauthorized alterations is presented in spherical coordinate system. Initially, the three dimensional (3D) model is translated from the Cartesian coordinate system to the spherical coordinate system. Then normalization technique is adopted to produce the normalized 3D cover model. An adaptive watermark is generated from each cover model by using the hamming code technique, and a simple least significant bit (LSB) substitution technique is employed for watermark data embedding. The verification data is absent in this paper because the verification task can be achieved by using the hamming code technique. The experiment results show that 100% vertices of the three dimensional (3D) model can be watermarked and verified. Moreover, the verification task can be achieved without the verification data in the proposed method.