From: seth at pricepages dot org
Operating system: Mac 10.4
PHP version: 5.2.1
PHP Bug Type: GD related
Bug description: Alpha composite allows color to bleed through
Description:
------------
I am filling the background of an image with a transparent red
(it shouldn't have an effect on the rest of the drawing). Over
it, I'm drawing a black, semi-transparent, square.
Reproduce code:
---------------
$img = imagecreatetruecolor(100, 100);
imagealphablending($img, true);
$trans = imagecolorresolvealpha($img,255,0,0, 127);
imagefill($img, 0,0, $trans);
$pTrans = imagecolorresolvealpha($img, 0,0,0, 64);
imagefilledrectangle($img, 10, 10, 50, 50, $pTrans);
imagealphablending($img, false);
imagesavealpha($img,true);
header('Content-Type: image/png');
imagepng($img);
Expected result:
----------------
I would expect the resulting image to be 100% transparent,
except for a grey, 50% transparent square.
Actual result:
--------------
Instead, the black is mixed with the red to form a dark-red
semi-transparent square. The red color should not be there,
because it was 100% transparent.
--
Edit bug report at http://bugs.php.net/?id=40572&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=40572&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=40572&r=trysnapshot52
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=40572&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=40572&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=40572&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=40572&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=40572&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=40572&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=40572&r=support
Expected behavior: http://bugs.php.net/fix.php?id=40572&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=40572&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=40572&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=40572&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=40572&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=40572&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=40572&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=40572&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=40572&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=40572&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=40572&r=mysqlcfg
