SSIM 3100948 180395056 2007-12-27T09:11:31Z 85.97.64.194 /* External links */ Link moved, updated The '''Structural SIMilarity''' (SSIM) index is a method for measuring the similarity between two images. The SSIM index is a full reference metric, in other words, the measuring of image quality based on an initial uncompressed or distortion-free image as reference. SSIM is designed to improve on traditional methods like [[PSNR]] and [[Mean squared error|MSE]], which have proved to be inconsistent with human eye perception. SSIM is also commonly used as a method of testing the quality of various [[lossy]] [[video compression]] methods. For example, the popular open source [[H.264]] encoder [[x264]] is set by default to display an SSIM value at the end of an encoding operation. The SSIM index is a decimal value between 0 and 1. A value of 0 would mean zero correlation with the original image, and 1 means the exact same image. 0.95 SSIM, for example, would imply half as much variation from the original image as 0.90 SSIM. Through this index, image and video compression methods can be effectively compared. ==References== * Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli, "[http://www.cns.nyu.edu/~zwang/files/papers/ssim.html Image quality assessment: From error visibility to structural similarity]," [[IEEE Transactions on Image Processing]], vol. 13, no. 4, pp. 600-612, Apr. 2004. ==See also== * [[PSNR]] * [[Video quality]] ==External links== * [http://www.ece.uwaterloo.ca/~z70wang/research/ssim/ Home page] * [http://mehdi.rabah.free.fr/SSIM/ C/C++ Implementation] [[Category:Image processing]] {{comp-sci-stub}} [[fr:SSIM]]