| 摘要 |
The invention concerns a method for evaluating perceptual image quantization distortion in a fixed image. This method takes into account the specific characteristics of the visual processing of an image to obtain the most accurate evaluation, based on the difference between the reference image (9) and the tested image (8) divided into a plurality of image blocks (I). On the basis of each image block (I), the method consists in computing (1) the luminance point Li,j and the adaptation luminance La, in a non-linear processing (2; 10) and in computing the intermediate contrast (2; 11) DELTA Li,j* = Li,j*-La*, in filtering it (3; 12) according to the spatial orientation of the frequencies, in separating (4;13) the frequencies according to orientation, in a second non linear processing (5; 14), and by computing the point-to-point difference weighted by frequency spatial orientation between the obtained intermediate contrast values, in deducing therefrom the value for each tested image block, the local perceptual contrast distortion.
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