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Re: Poor "scale" results

From: William Kern (
18125@xyz.molar.is)
Date: Sat 23 Feb 2008 - 04:11:47 GMT

  • Next message: Tony Cook: "Re: Poor "scale" results"

    Ask Bjørn Hansen wrote:
    > Hi everyone,
    >
    > I'm using Imager to scale basically random pictures (user uploaded
    > things) to various small sizes.
    >
    > I can never make it look good though! I seem to either have it too
    > blurry or too "sharp" -- either way it's losing details.
    >
    > I put up some examples at
    > http://tmp.askask.com/2008/02/imager/
    >
    > The original file:
    > http://tmp.askask.com/2008/02/imager/6-23lHGG_o.jpg
    >
    > With stddev 1.25 and scale 1:
    > http://tmp.askask.com/2008/02/imager/6-1NPnEW_s.jpg
    >
    > stddev 1.8 and scale 0.7:
    > http://tmp.askask.com/2008/02/imager/6-1NPnEW_s_18_07.jpg
    >
    > stddev 1.1 and scale 0.3:
    > http://tmp.askask.com/2008/02/imager/6-1NPnEW_s_1103.jpg
    >
    > As a test I scaled the image with Preview.app (too dark, but nice
    > detail):
    > http://tmp.askask.com/2008/02/imager/6-23lHGG_preview.jpg
    >
    > and with photoshop (similar filesize to the Imager files), much more
    > detail in the asphalt:
    > http://tmp.askask.com/2008/02/imager/6-23lHGG_ps.jpg
    >
    > In a blind test my coworkers here preferred the Photoshop version
    > (grrh). They tell me to just get over it and use Image-Magick, but
    > I've never done that and not regretted having to maintain the
    > ImageMagick/PerlMagick installation. :-)
    >

    yep. I love the simple Imager install/maintenance.

    > My code for doing this below -- anything obvious I'm doing wrong?
    >
    > my $data;
    > $img->write(data => \$data,
    > type => 'jpeg',
    > jpegquality => 82,
    > )
    > or die $img->errstr;
    >
    >
    >

    What happens when you leave the jpegquality at a higher level?

    Also I have a higher unsharp mask with stddev of 2 and a higher scale of 10.
    I am not sure why, we did that years ago when working with a picky
    designer.
    I may have to review those settings.

    -bill



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