Could I impose of some of our members to test this app on bitmaps. I have written a scaling algorithm based on StretchBlt with the HALFTONE setting and it is testing OK on my Win10 box. I have been testing on high res 1920 x 1080 bitmaps and from 100% down to very small the image quality seems to be OK. It will both upscale and downscale and the downscale images look clean and sharp but as expected, an upscaled image never improves on the original.