#39366 [Opn]: imagerotate preserve alpha channel only if degree less then 45
| From: | ciakana at gmail dot com | Date: | Fri, 03 Nov 2006 22:18:02 +0000 |
| Subject: | #39366 [Opn]: imagerotate preserve alpha channel only if degree less then 45 | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-104356@lists.php.net to get a copy of this message | ||
ID: 39366
User updated by: ciakana at gmail dot com
Reported By: ciakana at gmail dot com
Status: Open
Bug Type: GD related
Operating System: Windows XP
PHP Version: 5.2.0
New Comment:
Description:
------------
If I run the allegated script, where shade.png is a png image with a
transparent background (full alpha channel), all works if the degrees
are less then 45. If I set the degrees to 300, for example, the
background become black.
Reproduce code:
---------------
<?php
$filename="shade.png";
$degrees =300;
header('Content-type: image/png');
$source = imagecreatefrompng($filename);
$rotate = imagerotate($source, $degrees, -1);
imagealphablending($rotate, true);
imagesavealpha($rotate, true);
imagepng($rotate);
?>
Expected result:
----------------
A rotated copy of the original image with the alpha channel preserved
Actual result:
--------------
An image with a black bakground
Previous Comments:
------------------------------------------------------------------------
[2006-11-03 22:16:43] ciakana at gmail dot com
Description:
------------
If I run the allegated script, where shade.png is a png image with a
transparent background (full alpha channel), all works if the degrees
are less then 45. If I set the degrees to 300, for example, the
background become black.
Reproduce code:
---------------
<?php
$filename="shade.png";
$degrees =300;
header('Content-type: image/png');
$source = imagecreatefrompng($filename);
$rotate = imagerotate($source, $degrees, -1);
imagealphablending($rotate, true);
imagesavealpha($rotate, true);
imagepng($rotate);
?>
Expected result:
----------------
An image with a black bakground
Actual result:
--------------
A rotated copy of the original image with the alpha channel preserved
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/?id=39366&edit=1