Tampering Detection and Content Recovery for Digital Images Using Halftone Mechanism

In this paper, an effective self-embedding fragile watermarking method for tampering detection and content recovery is proposed. The halftone mechanism and the extension operation are utilized to generate recovery bits from the resized original image. Watermark bits including recovery bits and authentication bits only occupy one LSB plane of the original image. The located, tampered blocks can be recovered by the correctly extracted recovery bits, the reserved blocks, and the spatial correlation of the halftone image. Experimental results demonstrate that the proposed method can achieve satisfactory visual quality of watermarked image and recovered image even though the tampered area is larger.