1. A method for assessing image quality value of a distorted image with respect to a reference image, each image comprising pixels or image points, said method comprising the following steps: detecting edges on said reference and distorted images to generate two edge images, an edge strength value being associated with each pixel of coordinates (i, j) in said reference image and an edge strength value being associated with each pixel of coordinates (i, j) in said distorted image; thresholding said edge images to generate two edge maps, each map identifying edge pixels; dividing the reference image into non-overlapping blocks; estimating the level of texture for each block of said reference image by computing the number of edge pixels within each block and associate this value to each pixel within said block; and computing the masking capability of each pixel of coordinates (i, j) in said reference image based on the estimated levels of texture; computing, for each pixel of said distorted image, at least one quality level with respect to said reference image, wherein said computing consists in one or more of the following steps: computing a first quality level based on edge suppression level; or computing a second quality level based on edge apparition level; or computing a third quality level based on blocking effect level; adding, for said distorted image, said quality levels associated with each of said pixels by weighting them by a weight depending on a perceptual interest of said pixel in order to get said image quality value, said weight being lower for a pixel of high perceptual interest.