Alteration detection and image recovery using Halftone Replacement Prior Watermark Embedding

This study presents a watermarking scheme, namely Halftone Replacement Prior Watermark Embedding (HRPWE), for medical and surveillance systems applications. The proposed method provides better image quality and higher robustness to withstand attacks. Besides, EDF-based inverse halftoning approach is also proposed to detect alteration region and then recover the original image with low complexity advantage. Hence, it could be used in cooperating with HRPWE for surveillance images to withstand compression or unauthorized modification, and for medical images to detect and recover unauthorized modification. This approach is proved to be of excellent performances with extensive experimental results.