点评：一种基于Contourlet变换的质降参考图像质量评价方法，该方法利用Contourlet变换对图像的方向信息进行捕捉，有效地提取反映参考图像和测试图像的纹理结构信息的图像Contourlet变换域子带的变换系数矩阵的均值和标准差作为图像的统计特征值，通过比较参考图像和测试图像之间纹理结构信息的相似度，最终获得测试图像的质量分值，利用图像之间纹理结构信息的相似度进行图像质量评价可以不要求参考图像具有相当好的视觉质量，图像质量评价结果只单纯地反映参考图像与测试图像之间的相似度，即评价结果可以客观地反映图像处理或压缩算法对图像质量变化的影响。

Comment: The invention discloses a degraded reference image quality evaluation method based on Contourlet transformation. The method utilizes Contourlet transformation to catch the direction information of an image, effectively extracts the average value and the standard deviation of a transform coefficient matrix of an image Contourlet transformation domain sub-band reflecting the texture structure information of a reference image and a tested image as statistical attribute values of the image; by comparing the similarity of the texture structure information between the reference image and the testedimage, the quality value of the tested image is finally obtained; image quality evaluation carried out by utilizing the similarity of the texture structure information between images does not requirethe reference image of very good visual quality, and the result of image quality evaluation purely reflects the similarity between the reference image and the tested image, namely, the result of evaluation can objectively reflects the influences of image processing or compression algorithm on the change of image quality.