Performance analysis of a content authentication semifragile watermark

One design challenge for content authentication watermarks is to achieve a good balance between robustness against mild incidental image distortions and fragility to tampering attacks. A content authentication watermark should protect the integrity of the image content rather than its exact representation. We present performance analysis of a wavelet-based semifragile watermark in terms of its resistance to mild incidental distortions. Based on our experimental results, we analyze the watermark detection rates for each wavelet decomposition level. Simulation results are also used to study how the features of an image might affect the performance of watermarking algorithms. We also present an evaluation technique that allows for choosing the proper algorithm parameters for embedding the watermark bits, hence maximizing watermark robustness to mild distortions while maintaining good visual quality of watermarked images.