Due to the very fast growth of data in the last few decades, it is very important to provide new methods to secure these data. In this paper, we propose a new approach which will be able to mark digital images with an invisible and undetectable information, known as “watermark”. The originality of our approach, is based on orthogonal polynomial basis transform which consists of decomposing an image into two components: texture and structure, by projecting the original image into a bivariate polynomial basis. This transformation is based on a mathematical model as close as possible to human visual system model, for the purpose of texture extraction of an image. A watermark is embedded into the texture component in order to obtain the best compromise between imperceptibility and robustness of watermarked image. Our experimental results and comparison analysis for the proposed method achieved good results, compared to existing methods, in terms of robustness and imperceptibility of the inserted watermark.