Try to do a search based on the article
is there such a moment
Since our hash is 64битное number requires 32 bytes of descriptor to shrink in 8 bytes and it does not lose much accuracy.
After some tests it was decided to try these 32 bytes are present in the form of a matrix of 16x16-bit. And then this matrix to pass through a perceptual hash PHash. The result was supposed to be just a 64 bit number.
And that's how it is I have no ideas how this matrix to feed in cv::dct from opencv or https://www.phash.org/
Interested in the solution in c++ but it'll do and any other language
In the repository the author of the article (huge respect to him by the way) is not found in the example conversion of the descriptor in the hash https://github.com/valbok/img.chk