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This queue is for tickets about the Imager CPAN distribution.

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The Basics
Id: 59709
Status: open
Priority: 40/
Queue: Imager

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Owner: Nobody in particular
Requestors: vindex [...] apartia.org
Cc:
AdminCc:

Bug Information
Severity: Normal
Broken in: (no value)
Fixed in: (no value)



Subject: thumbnail quality problem
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Imager scale quality is too low. We have much better results with the Image::Imlib2 module. Here is a comparaison of two thumbmnails produced from the same source with default settings: http://zenon.apartia.fr/stuff/made_with_imager.jpg http://zenon.apartia.fr/stuff/made_with_imlib2.jpg The 'Imager' version is fuzzy and lacks definition. I tried with the 'mixing' algorithm with no apparent difference.
Subject: made_with_imlib2.jpg
made_with_imlib2.jpg
Subject: made_with_imager.jpg
made_with_imager.jpg
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On Mon Jul 26 08:40:37 2010, vindex wrote: Show quoted text
> Imager scale quality is too low. We have much better results with the > Image::Imlib2 module. > > Here is a comparaison of two thumbmnails produced from the same source > with default settings: > > http://zenon.apartia.fr/stuff/made_with_imager.jpg > > http://zenon.apartia.fr/stuff/made_with_imlib2.jpg > > The 'Imager' version is fuzzy and lacks definition. I tried with the > 'mixing' algorithm with no apparent difference.
Could I please have: - the source image - the code you used to test the mixing option. Thanks, Tony
Subject: Re: [rt.cpan.org #59709] thumbnail quality problem
Date: Tue, 27 Jul 2010 09:32:40 +0200
To: TONYC via RT <bug-Imager [...] rt.cpan.org>
From: Louis-David Mitterrand <vindex [...] apartia.org>
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On Mon, Jul 26, 2010 at 07:53:56PM -0400, TONYC via RT wrote: Show quoted text
> <URL: https://rt.cpan.org/Ticket/Display.html?id=59709 > > > On Mon Jul 26 08:40:37 2010, vindex wrote:
> > Imager scale quality is too low. We have much better results with the > > Image::Imlib2 module. > > > > Here is a comparaison of two thumbmnails produced from the same source > > with default settings: > > > > http://zenon.apartia.fr/stuff/made_with_imager.jpg > > > > http://zenon.apartia.fr/stuff/made_with_imlib2.jpg > > > > The 'Imager' version is fuzzy and lacks definition. I tried with the > > 'mixing' algorithm with no apparent difference.
> > Could I please have: > > - the source image > > - the code you used to test the mixing option.
Hi, It seems my initial tests were flawed because the 'mixing' algorithm is indeed much better than 'normal' and (almost?) equivalent to Image::Imlib2's default scale quality. Please find attached the original image and test script. There is something confusing in the Imager::Transformations docs: "preview" is faster than "mixing" which is much faster than "normal". If 'mixing' is faster and better than 'normal' then why isn't it the default? Cheers, -- http://www.cruisefish.net
Download scale_test.pl
text/x-perl 987b

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Download allroad.jpg
image/jpeg 175.7k

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Subject: Re: [rt.cpan.org #59709] thumbnail quality problem
Date: Tue, 27 Jul 2010 17:35:48 +1000
To: Louis-David Mitterrand via RT <bug-Imager [...] rt.cpan.org>
From: Tony Cook <tony [...] develop-help.com>
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On Tue, Jul 27, 2010 at 03:32:51AM -0400, Louis-David Mitterrand via RT wrote: Show quoted text
> It seems my initial tests were flawed because the 'mixing' algorithm is > indeed much better than 'normal' and (almost?) equivalent to > Image::Imlib2's default scale quality. > > Please find attached the original image and test script. > > There is something confusing in the Imager::Transformations docs: > > "preview" is faster than "mixing" which is much faster than "normal". > > If 'mixing' is faster and better than 'normal' then why isn't it the > default?
Backward compatibility mostly. mixing was added several years after the default scaling algorithm as implemented. I have an open ticket to look at scaling, but time (and enthusiasm) has meant I haven't gotten around to it. Tony


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