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[SOLVED] IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:13:48-07:00
by NicolasRobidoux
Bleeding edge, up to date, IM6 and IM7: svn rev 9368, both compiled in HDRI mode on up to date Linux Mint 12.

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convert rose: input_rose.jpg
convert input_rose.jpg -resize 500% IM6rose.jpg
magick input_rose.jpg -resize 500% IM7rose.jpg
The max difference between the two images is 39, which is huge.
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I'll try to narrow down the problem.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:15:46-07:00
by NicolasRobidoux
I think IM7 is the broken one.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:22:02-07:00
by NicolasRobidoux
It's not a JPEG issue: Same if I use png.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:23:54-07:00
by NicolasRobidoux
It's not a negative lobe issue: Same with -filter Triangle.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:25:44-07:00
by NicolasRobidoux
Just to make sure it's clear:

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convert -version
Version: ImageMagick 6.7.9-6 2012-09-15 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP  HDRI
magick -version
Version: ImageMagick 7.0.0-0 2012-09-15 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP  HDRI

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:32:19-07:00
by NicolasRobidoux
Not so sure it's IM7 that's broken.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:50:40-07:00
by NicolasRobidoux
The bleeding edge IM6 compiled with everything default (make clean && ./configure && make && sudo make install) gives the exact same result as shown in http://www.imagemagick.org/Usage/resize ... _sigmoidal (IM v6.7.9-1) with the following command:

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convert rose: -colorspace RGB  -filter Lanczos  -resize 200x \
           -colorspace sRGB rose_resize_RGB.new.png
(And an extremely different result when compiled in HDRI, which is not surprising given the negative lobes.)
I don't know what is going on.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T09:53:23-07:00
by NicolasRobidoux
I should go back to earlier IM7 and see if there is a difference, but I'll go buy winter tires instead.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T12:40:56-07:00
by NicolasRobidoux
-distort resize appears to be fine.
It's a -resize issue.

Re: [SOLVED] IM6 and IM7 give very different -resize results

Posted: 2012-09-15T17:12:16-07:00
by NicolasRobidoux
As of svn rev 9379, this seems to be fixed.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T17:14:51-07:00
by NicolasRobidoux
Still broken:

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convert rose: input_rose.jpg
convert input_rose.jpg -resize 500% IM6rose.jpg
magick input_rose.jpg -resize 500% IM7rose.jpg
still gives different images.
What fooled me for a minute is that

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magick rose: -resize 500% IM7rose.jpg
convert rose: -resize 500% IM6rose.jpg
give identical images.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-15T17:17:38-07:00
by NicolasRobidoux
A-ah! Could it be that IM6 and IM7 use different JPEG settings?

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convert rose: input_rose.png
convert input_rose.png -resize 500% IM6rose.png
magick input_rose.png -resize 500% IM7rose.png
do give identical images.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-17T10:42:03-07:00
by NicolasRobidoux
No: convert rose: roseIM6.jpg (with IM6 convert) and magick rose: roseIM7.jpg give identical images.

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-18T08:56:03-07:00
by NicolasRobidoux
jpeg.c was just updated in both IM6 and IM7, but

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convert rose: input_rose.jpg
convert input_rose.jpg -resize 500% IM6rose.jpg
magick input_rose.jpg -resize 500% IM7rose.jpg
still gives different images.
For reference:

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magick -version
Version: ImageMagick 7.0.0-0 2012-09-17 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP  HDRI  
convert -version
Version: ImageMagick 6.7.9-7 2012-09-16 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP  HDRI

Re: IM6 and IM7 give very different -resize results

Posted: 2012-09-18T09:16:29-07:00
by NicolasRobidoux
Again for the record, this is how I compile both IM6 and IM7 (--enable-hdri is now unnecessary with IM7, but it should not hurt):

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make clean && CFLAGS="-march=native" CXXFLAGS="-march=native" ./configure --enable-hdri && make && sudo make install