Internet has affected our everyday life drastically. Expansive volumes of information are exchanged over the Internet consistently which causes numerous security concerns. Issues like content identification, document and image security, audience measurement, ownership, copyrights and others can be settled by using digital watermarking. In this work, robust and imperceptible nonblind color image watermarking algorithm is proposed, which benefit from the fact that watermark can be hidden in different color channel which results into further robustness of the proposed technique to attacks. Given method uses some algorithms such as entropy, discrete wavelet transform, Chirp z-transform, orthogonal-triangular decomposition and Singular value decomposition in order to embed the watermark in a color image. Many experiments are performed using well-known signal processing attacks such as histogram equalization, adding noise and compression. Experimental results show that the proposed scheme is imperceptible and robust against common signal processing attacks.

Ozet(;e -internet iizerinden dagllan saYlsal ortam bilgisinin artmasl, giivenlik ve gizlilik endi�elerini de beraberinde getirmi�tir. Uretilen saYlsal ortamm miktan ve oynamasl, tatmin edici damgalama yontemlerine olan ihtiyaci da dogurmu�tur. Bu �ah�mada, yiiz sezimine dayah giirbiiz gri diizeyi damgalama teknigi onerilmektedir. Viiz sezimi algoritmasl imgedeki yiizii bulmak i�in kullaDllml�tlr. imgenin bu klsml Aynk Dalgaclk Donii�iimii kullaDllarak frekans bOigesine aktanlml�tlr. Bir onceki dii�iik frekans altbandma z-donii�iimii (CZT), sonu� klsmma ise LU ayn�tlrma metodu uygulanml�tlr. LU ayn�tlrma yonteminden �Ikan ko�egen matris Tekil Deger Ayn�tlrma metodu kullaDllarak daha fazla ayn�tlrllml�tlr ve tekil degerlere damga gomiilmii�tiir. Algoritma bir�ok deneyle test edilmi� ve sonu�lar en geli�kin ozgiin yontemlerle kar�lla�tlnlml�tlr. Gozlenen sonu�lar, onerilen metodun iyi derecede goriilmezlik i�erdigini ve giirbiiz karakteristiginin oldugunu ortaya koymaktadlr. Anahtar Kelimeler: Z Donii�iimii, Aynk Dalgaclk Donii�iimii, yiiz sezimi, LU ayn�tlrma, Tekil Deger Ayn�tlrma, damgalama. Abstract-Due to increase of usage of digital media distributed over the Internet, concerns about security and piracy have emerged. The amount of digital media reproduction has brought a need for content watermarking. In this paper robust grayscale watermarking technique based on face detection is proposed. Face detection algorithm is used to find a face on host image and this part of image is transformed into frequency domain using Discrete Wavelet Transform. Chirp z-transform is applied on low-frequency subband from previous step and LU decomposition is used on the outcome. Diagonal matrix from LU decomposition is further decomposed using Singular Value Decomposition and watermark is embedded into singular values. Numerous experiments are run on that algorithm and results are compared with novel and state-of-the-art techniques. The resultsshow that proposed method has good imperceptibility and robustness characteristics.