A SVD- and quantization based semi-fragile watermarking technique for image authentication

With the popularity of digital images applied in journals, hospitals and courtrooms, it has become easier to modify or forge information using widely available editing software. Digital watermarking techniques have been proposed as an effective solution to the problem of image authentication. This paper presents a semi-fragile watermarking technique based on block singular value decomposition (SVD). It embeds the binary watermark image of pseudo-random permutation into the biggest singular value by quantization process. The scheme can extract the watermark without the original image. Experimental results show that the proposed scheme can prevent malicious attacks but allow JPEG lossy compression and can locate alterations made on the image.