#41820 [Com]: Color noise in resized image when using IMAGECOPYRESAMPLED
| From: | neo at lozhki dot net | Date: | Wed, 29 Apr 2009 21:52:48 +0000 |
| Subject: | #41820 [Com]: Color noise in resized image when using IMAGECOPYRESAMPLED | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-136525@lists.php.net to get a copy of this message | ||
ID: 41820
Comment by: neo at lozhki dot net
Reported By: richard dot gavenda at rksting dot cz
Status: No Feedback
Bug Type: GD related
Operating System: Windows XP
PHP Version: 5.2.3
Assigned To: pajoye
New Comment:
Is there a solution now after two years?
Previous Comments:
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[2008-07-28 01:00:00] php-bugs at lists dot php dot net
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
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[2008-07-20 13:44:55] pajoye@php.net
Can you try the patch available at #45030 please?
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[2007-06-28 10:14:26] richard dot gavenda at rksting dot cz
Ok, so let's close whis thread. I will wait for future versions :-)
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[2007-06-28 10:12:15] richard dot gavenda at rksting dot cz
So there must be some sort of bug in resampling algorithm. When i
resizing bitmap filled with solid color in any bitmap editor, using any
aproximation (linear, bicubic, etc.) I get an image filled with exactly
same solid color.
With this issue I'm unable to reach one bit transparency of resized
image.
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[2007-06-28 10:08:08] pajoye@php.net
"Position of horizontal and vertical stripes is different on different
machines."
Yes, it is the problem with floating points value when we need a
constant and precise result on different architecture. See;
http://docs.sun.com/source/806-3568/ncg_goldberg.html
for a good
explanation about this problem.
For example, your images has variation between 126 and 127 for a given
channel. It may be only something like 126.49999 and 126.50000.
I don't think I can fix it easily for this implementation (bicubic
interpolation using floating points implementation).
Future versions will have more filters and using less volatile
precisions.
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the rest of the comments, please view the bug report online at
http://bugs.php.net/41820
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