Bug #61221 [NEW]: imagegammacorrect function loses alpha channel

From: Operating system: PHP version: 5.4.0RC8 Package: GD related Bug Type: Bug Bug description:imagegammacorrect function loses alpha channel Description: ------------ When issuing imagegammacorrect function on an image resource that has alpha channel, the alpha channel gets lost. I looked at the source of 5.4.0RC8 and have also made a minor patch that adds alpha channel support by modifying the ext/gd/gd.c file. Test script: --------------- $img = imagecreatefrompng('input.png'); imagegammacorrect($img, 1.0, 1.0); imagepng($img, 'result.png'); Expected result: ---------------- I would expect to see output.png retain its alpha channel. Actual result: -------------- The result file does not have any transparency, since the current source code indeed does not do gamma correction to alpha channel. -- Edit bug report at https://bugs.php.net/bug.php?id=61221&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=61221&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=61221&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=61221&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=61221&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=61221&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=61221&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=61221&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=61221&r=needscript Try newer version: https://bugs.php.net/fix.php?id=61221&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=61221&r=support Expected behavior: https://bugs.php.net/fix.php?id=61221&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=61221&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=61221&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=61221&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=61221&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=61221&r=dst IIS Stability: https://bugs.php.net/fix.php?id=61221&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=61221&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=61221&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=61221&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=61221&r=mysqlcfg