A hybrid digital image watermarking algorithm based on DCT‐DWT and auto‐thresholding

Abstract

AbstractMultimedia evolution in the current era has given digital images security and privacy a great concern. Digital image watermarking is used to produce highly protected images in order to promote secure and protected exchange over the network and between individuals. In this paper, a robust algorithm for digital image watermarking is proposed based on a hybrid watermarking and auto‐thresholding. This algorithm is designed to embed the watermarks in the transform domain using both discrete cosine transform and discrete wavelet transform (DCT‐DWT). Image is transformed to DCT then to DWT and the algorithm trains itself to choose the best embedding threshold. This threshold must satisfy a performance trade‐off and at the same time attains high imperceptibility and robustness. The algorithm performance is evaluated under various attacks and showed high‐performance level. Imperceptibility evaluation showed peak signal‐to‐noise ratio above 42.96 dB and similarity percentage above 99.27%. The algorithm proved high resistance to noising, scaling, cropping, rotation, and compression attacks. Copyright © 2015 John Wiley & Sons, Ltd.