opensource photo matching based on the PhotoDNA concepts. I read about this years ago and thought it was interesting so decided to see what was involved with it. Rotations and mirror/flips will need to be added to reorient the images to have a higher degree of matching success.
Used this as a reference: https://news.microsoft.com/en-gb/2013/11/18/tacklingproliferatio/
IMAGE DNA1: 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,6,174,172,169,4,37,142,144,61,27,38,17,36,118,127,85,7,174,177,174,36,67,161,116,58,32,62,26,9,89,116,113,7,180,178,174,172,193,173,174,55,41,74,14,5,82,98,114,7,182,180,176,205,205,168,189,55,92,42,5,17,90,68,107,7,182,180,182,192,144,196,194,74,128,99,2,1,66,86,113,7,182,182,210,188,197,213,196,158,166,102,39,2,39,105,112,7,181,208,218,181,186,204,188,168,149,173,44,17,25,78,117,7,186,197,150,201,206,202,186,192,161,114,19,28,27,20,102,7,214,198,200,221,205,202,198,190,126,75,51,60,27,47,11,8,217,184,188,206,206,221,200,194,60,148,64,62,28,95,27,7,150,206,213,206,193,204,212,196,45,47,45,80,79,83,27,7,201,220,206,210,205,204,200,194,56,45,52,37,41,38,79,3,186,201,208,222,206,210,201,204,47,46,37,55,74,44,52,8,205,206,176,204,210,204,202,208,58,47,32,45,34,39,42,8,206,206,205,202,205,202,206,218,198,59,35,22,22,25,38 = 28483
IMAGE DNA2: 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,6,174,172,169,5,37,142,144,61,27,38,17,35,118,127,85,7,174,177,174,37,66,161,116,58,33,62,27,9,89,117,114,7,180,178,174,170,193,173,173,54,42,74,14,5,83,98,114,7,182,180,177,204,206,168,190,55,92,42,5,17,90,68,106,7,182,180,182,192,144,196,194,74,128,99,2,1,66,85,113,7,184,182,209,188,197,213,196,158,166,102,39,1,38,105,112,7,181,209,218,181,186,204,188,168,150,173,44,18,25,78,117,7,186,197,150,202,206,202,186,190,160,114,20,27,27,20,101,7,214,198,198,222,204,202,198,190,126,75,51,60,28,47,11,8,218,184,186,206,205,221,198,194,61,148,64,62,28,95,27,7,150,206,213,206,193,204,212,194,44,47,45,80,80,83,27,7,201,220,208,210,205,204,200,194,56,45,52,37,41,39,79,3,186,201,209,222,206,210,201,204,47,46,37,55,74,44,52,8,205,206,176,204,210,204,202,208,58,47,32,45,34,38,42,8,206,206,204,202,205,202,205,218,198,59,35,22,23,25,37 = 28480