improved cloning test
improve decolor tests
fix regressiont ests npr
fix grayscale loading
constness
adds header guards + move impl to proper file
rename stuff, adds logging and replace shitty else if chain by switch
refactor array_product
rename variables
remove useless buffers
backport bug fix
remove some more useless buffers and rename a bunch of variables
remove logging
replace double* by vector<double>
replace 8 loops by 2
this has been submitted to the daily wtf
simplify a line
replace double by float
replace implementation of dst
remove debugging code