ks26+@andrew.cmu.edu (Kenneth Sykes) (05/19/89)
In working with the Windows StretchBlt function I have come across the problem of scanlines being truncated that are important for the overall definition of an image. For example a bitmap containing a rectangle with one pixel borders can lose one or more of the borders if the stretching algorithm decides to throw away the scanline containing the border (similarly for the vertical edges.) I diddn't think much of this until I mentioned the problem to a friend that programs Macs, and he diddn't notice this problem on the mac. After creating rectangles in two different bitmap editors and noticing the rectangle maintained all the borders as it was shrunk suggests there might be a better way to shrink bitmaps than the algorithm Windows uses. Any Mac gurus have insights as to how the Mac does this? This seems like a hard problem to solve in general. Any help would be greatly appreciated. Sincerely, Ken Sykes