Stamping techniques in digital image processing and a new approach based on chaos

One of the most crucial issues that have occurred in recent years is the copyrights on digital images. One of the most effective approaches of preserving digital images is digital watermarking. Digital watermarking is the process of signing the image as your own. There are two kinds of this process, one of which visible and the other one is invisible digital watermarking. Visible digital watermarking is the printing of videos and images in such a way that the watermarked is clearly visible. In this sort of watermarked, the objective is not only copyright, but also to unearth the owner of the image while spreading the image. In invisible digital watermarking, it is aimed that the stamp added to the image is not realized by the watchers. In this genre of stamping, QR codes of different sizes are mostly used. In this study, an invisible digital watermarking technique tested with a total of 12 QR codes in 3 different sizes is recommended. Initially, the image and the digital watermarking are transformed into the binary system. The lower 4 bits of each 8-bit pixel in the image are then used for watermarked. Hence the change in the watermarked image is tried to be minimized. When applying the digital watermarking to the image, pixel positions are mixed with a newly proposed chaotic map so that it is not easily removed. Besides, the newly proposed chaotic map is also used when placing a digital watermarking on the image. In addition, in this study, a new one-dimensional chaotic map is proposed for use in digital watermarking and image encryption. This newly proposed chaotic map has displayed high success in all tests. As a result, while the proposed digital watermarking technique places the digital watermarking on the image, the distortion in the image was also measured by the peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) tests. Most PSNR and SSIM results are greater than 50 and very close to 1, respectively. This shows that the proposed watermarked method is very successful.