Bug #66714 [NEW]: imageconvolution processing output inconsistent with previous versions
From: drew dot mclellan at gmail dot com
Operating system: Linux
PHP version: 5.5.9
Package: GD related
Bug Type: Bug
Bug description:imageconvolution processing output inconsistent with previous versions
Description:
------------
The behaviour of imageconvolution() appears to have changed in PHP
5.5.9. The results are visual, so hard to describe, but the behaviour is
significantly different from earlier versions.
The test script is boilerplate code for basic image sharpening, as found
all over the web. In PHP 5.5.9 the result is a loss of brightness in the
resulting image.
Test script:
---------------
$image = imagecreatefromjpeg('/path/to/picture.jpg');
$matrix = array(array(-1, -1, -1), array(-1, 20, -1), array(-1, -1,
-1));
$divisor = array_sum(array_map('array_sum', $matrix));
imageconvolution($image, $matrix, $divisor, 0);
echo imagecolorat($image, 0, 0);
Expected result:
----------------
The echo'd output (colour reference number at 0,0) should be the same in
PHP 5.5.8 and 5.5.9 for the same input image.
Actual result:
--------------
The output number is much lower in 5.5.9 than 5.5.8, indicating a darker
colour and a loss of brightness. The issue is that the behaviour has
changed.
--
Edit bug report at https://bugs.php.net/bug.php?id=66714&edit=1
--
Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=66714&r=trysnapshot54
Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=66714&r=trysnapshot55
Try a snapshot (trunk): https://bugs.php.net/fix.php?id=66714&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=66714&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=66714&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=66714&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=66714&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=66714&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=66714&r=support
Expected behavior: https://bugs.php.net/fix.php?id=66714&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=66714&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=66714&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=66714&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=66714&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=66714&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=66714&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=66714&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=66714&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=66714&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=66714&r=mysqlcfg
Thread (8 messages)
- drew dot mclellan at gmail dot com