On Thu, 5 Apr 2001, Stephan E. Schlierf wrote:
> Hm, more and more I come to the point that this is a problem with gs 6.50.
Ah! Now I know exactly what is the problem. The images in your PDF are
compressed using a lossy compression, you could think as if they are
converted to JPEGs.
You must configure gs to NOT compress the images lossy. Use lossless
compression or no compression at all. I don't know how to tell that to gs,
but read the documentation.
Some background: JPG uses DCT-transform on 8x8 blocks and quantizes the
coefficients. This will be very bad for computer-generated images that
have sharp edges, like your screen captures. When you examine some text
label on the grey background, you can see that the text causes noise
inside the whole 8x8-pixel block where it resides.
You might think about using less compression to have better quality
pictures. This doesn't work very well. JPEG-compression style is just
completely unsuited for this kind of images, and you must not to use it at
all.
