Bug #66714 [Com]: imageconvolution processing output inconsistent with previous versions

Edit report at https://bugs.php.net/bug.php?id=66714&edit=1 ID: 66714 Comment by: chris at lodesys dot com Reported by: drew dot mclellan at gmail dot com Summary: imageconvolution processing output inconsistent with previous versions Status: Open Type: Bug Package: GD related Operating System: Linux PHP Version: 5.5.9 Block user comment: N Private report: N New Comment: Seeing the same problem in Windows. In testing, it appears that the $sharpenMatrix is being ignored by imageconvolution() and a matrix of all 1's is being used instead. This results in a blurred image no matter what values are used for $sharpenMatrix. I consider this a critical bug as my sites rely on the ability to resize and sharpen images (with imageconvolution). Have had to revert to 5.9.8. Previous Comments: ------------------------------------------------------------------------ [2014-02-14 19:22:34] drew dot mclellan at gmail dot com 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 this bug report at https://bugs.php.net/bug.php?id=66714&edit=1