Legacy ImageMagick Discussions Archive

Dear all,

Imagemagick implements the PHASH (percetual hash) algorithm in the compare command. It is not clear, however, how the PHASH was specifically implemented. Does anyone have a reference to an article or publication that was used as the basis for the implementation?

Thank you!

For references, see Fred's paper http://www.fmwconcepts.com/misc_tests/p ... index.html

Since he wrote that, the IM implementation has changed to allow for different colorspaces to be used, instead of sRGb and HCL.

The reference in the link to my web site that was used is http://www.naturalspublishing.com/files ... g3omq1.pdf