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% H. R. Sheikh and A. C. Bovik, "Image Information and Visual Quality", IEEE Transactions on 
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This software release consists of an implementation of the algorithm described in the paper:

H. R. Sheikh and A. C. Bovik, "Image Information and Visual Quality"., IEEE Transactions on Image Processing, (to appear).
Download manuscript draft from http://live.ece.utexas.edu in the Publications link.


It consists of the following files:

readme.txt: this file
vifvec.m: main function, call this to evaluate image quality
support .m files: ind2wtree.m, refparams_vecgsm.m, vifsub_est_M.m

Prerequisites: The Steerable Pyramid toolbox. Available at
http://www.cns.nyu.edu/~lcv/software.html

Input : (1) img1: The reference image as a matrix
        (2) img2: The distorted image (order is important)

Output: (1) VIF the visual information fidelity measure between the two images

Default Usage:
   Given 2 test images img1 and img2, whose dynamic range is 0-255

   vif = vifvec(img1, img2);

Advanced Usage:
   Users may want to modify the parameters in the code. 
   (1) Modify sigma_nsq to find tune for your image dataset.
   (2) MxM is the block size that denotes the size of a vector used in the
   GSM model.
   (3) subbands included in the computation


Please read the paper for more details on interpretation of the results.
Email comments and bug reports to hamid.sheikh@ieee.org