A review on multiple Watermarking techniques in digital photography for Image authentication and encryption

Abstract: A digital watermark is an invisible signature embedded inside an image to show authenticity and ownership. To avoid obstruction of the original image effective digital watermark must be perceptually imperceptible. It should be statistically invisible to prevent detection, and it should also be robust to many image manipulations, such as filtering, additive noise, and compression. Digital watermarking has been invented and researched as a novel, unconventional method to implement the logical possessions privileges and defend digital media from tampering. It consists of a process of embedding into a mass signal a perceptually visible digital signature, message communication. In the proposed watermarking system, the discrete wavelet transform (DWT) is used for embedding watermarks and watermark is generated from the content of the original image and, as it is aclearanalysis technique for evaluatingtime- frequency, which can be well improved for extracting the information pleased of the image.

Keywords: Digital Watermarking, Amold Transform, Transparent Digital Signature, Discrete wavelet transforms (DWT)