A novel fast self-restoration semi-fragile watermarking algorithm for image content authentication resistant to JPEG compression

Abstract

In the past few years, semi-fragile watermarking has become increasingly important to verify the content of images and localise the tampered areas, while tolerating some non-malicious manipulations. Moreover, some researchers proposed self-restoration schemes to recover the tampered area in semi-fragile watermarking schemes. In this paper, we propose a novel fast self-restoration scheme resisting to JPEG compression for semi-fragile watermarking. In the watermark embedding process, we embed ten watermarks (six for authentication and four for self-restoration) into each 8 ×8 block of the original image. We then utilise four (4 ×4) sub-blocks' mean pixel values (extracted watermarks) to restore its corresponding (8 ×8) block's first four DCT coefficients for image content recovering. We compare our results with Li et al. and Chamlawi et al. DCT related schemes. The PSNR results indicate that the imperceptibility of our watermarked image is high at 37.61 dB and approximately 4 dB greater than the other two schemes. Moreover, the restored image is at 24.71 dB, approximately 2 dB higher than other two methods on average. Our restored image also achieves 24.39 dB, 22.98 dB 21.18 dB and 19.98 dB after JPEG compression QF =95, 85, 75 and 65, respectively, which are approximately 2.5 dB higher than other two self-restoration methods. © 2012 Springer-Verlag.