I want to shrink monochrome images in high quality. I have tried to use StretchBlt and set stretch mode to HALFTONE. The effect is very good but the HALFTONE mode doesn't support WIN9x. And I also tried to apply convolution algorithm to smooth images before shrinking, when the shrinking rate is not very high, say 0.4, the effect is acceptable, but if the rate is high, less than 0.3, the effect is bad. To improve the shrinking quality, I have convert the monochrome images from 1 bit to 8 bit format. Is there anyone know how do I shrink images in high quality?