in reply to permagick jpg compression

What operations did you perform on $background preceding the Write call? It's likely your quality loss occurs there instead of in the Write.

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Re^2: permagick jpg compression
by Anonymous Monk on Mar 19, 2007 at 21:20 UTC
    nothing

    I have cut out all the code between the read and write:
    $background->Read("$filename"); $background->Write(filename=>"$newfilename", quality=>100);
    whatever the quality setting is set at, or if it is not there at all, I get the same result - the image has gone from 95k to 13k and is clearly less sharp and detailed.
      What's your version of ImageMagick?

      I can't confirm such a big reduction in size. I tried exactly your code on an image of 704104 bytes, and the output was 704085 bytes. The quality reduction wasn't appreciable either.

      FWIW, we use ImageMagick 6.1.5 compiled from source, with the latest libjpeg.

        the package is called PerlMagick-6.24
        (it is on windows if that makes any difference)