Binomial Transform Based Image Authentication (BTIA)

Abstract

In this paper, a fragile watermarking technique based on Binomial transform (BT) has been proposed for color image authentication (BTIA). An initial adjustment is applied to adjust the pixel values. The Binomial transform (BT) is applied to convert each pair of pixel components into transform domain in row major order. Two bits of the authenticating watermarks, starting from the least significant bit position are embedded into each component of transformed pair. A post-embedding adjustment has also been incorporated to keep the embedded component values closest to the original without hampering the embedded watermark bits. The inverse Binomial transform (IBT) is applied on each adjusted pair to regenerate the pixel components which successively produce the watermarked image. At the receiving end, the whole watermark can be extracted by the reverse procedure which can be verified for authentication by obtaining a message digest. Experimental results conform that the proposed technique offers a higher payload and PSNR over existing techniques [7, 9].