Integration of a digital watermarking system into a Morphological Scene Change Detector (MSCD) for tamper prevention and detection

Abstract

Digital image watermarking is the process of embedding information into a digital image which may be used to verify its authenticity or the identity of its owners. This is the same as paper bearing a watermark for visible identification such as in money for example. In digital watermarking, if the signal is copied, then the information also is carried in the copy, proving that the data has been copied. In this paper, a digital watermarking approach is investigated using the DSP Builder methodology in order to provide the Morphological Scene Change Detector (MSCD) with a means by which if it detects an intruder, a watermarked copy of the triggering image is produced. This is so that if the image is required as proof in a court case; it can help show that the image has not been tampered with by means of the watermark. The system uses an 8-bit greyscale image and maps a binary watermark image onto the lowest bit level; this is then used when the MSCD is triggered. For simplicity in this case, the watermark image is the same size and the target image to be watermarked, future variations with foresee a variable watermark image size. The result will be a watermarked image that if a section is copied and pasted into another file and that file is then analysed, the watermark will be visible. The process of integrating the watermarking process into the MSCD will also be discussed as this system originally used binary images to speed up the process. Finally, this watermark system can be used with any system designed as all that is required is to insert the sub-system into a larger system meaning that it is extremely interchangeable. Keywords: Digital Watermarking, Scene Change Detection, FPGA, DSP Builder.