Our Windows Color Picker tool has an inbuilt magnifier and allows you to save full palettes of colors.
Posted in the ColorPic Forum.
Currently ColorPic v5.1 does calculate the "sum" of 3x3 or 5x5 pixel areas as the arithmetic mean value. That is nonsense and gives the wrong result.
This because you have to convert the nonlinear sRGB values first to linear numbers. Then you can calculate the average and after this you have to convert back to sRGB. Only this does result in the correct perceived color and brightness as defined with the transfer function of IEC 61966-2-1:1999. See https://en.wikipedia.org/wiki/SRGB
Take a white/black checkerboard with sRGB=000/255. Color picker does not show the correct value of 188 (50 %), but something around 128 (21 %) which is wrong.
I would like to purchase an updated version of ColorPic for a good price, when this correction is taken into account.