#34992 [Asn->Fbk]: imageconvolution does not respect alpha

ID: 34992 Updated by: pajoye@php.net Reported By: jaanus at underwerks dot com -Status: Assigned +Status: Feedback Bug Type: GD related Operating System: Linux 2.6.13 PHP Version: 6CVS-2005-10-26 (snap) Assigned To: pajoye Previous Comments: ------------------------------------------------------------------------ [2005-10-26 14:52:28] pajoye@php.net Please provide the images you use for this test and images you like to have as result (specifying which software you use). I'm not sure about the use of alpha with convolution filter but aesthetic toys. Interpolate the alpha using the convolutions make little sense, what it does now is to get the src alpha value for a given result pixel (x,y). As a second point, you talk about background color, this is something different as the alpha channel for a given pixel. ------------------------------------------------------------------------ [2005-10-26 12:42:07] tony2001@php.net Assigned to the maintainer. ------------------------------------------------------------------------ [2005-10-26 11:15:59] jaanus at underwerks dot com Description: ------------ imageconvolution destroys 8bit alpha channel in subject image Reproduce code: --------------- <?PHP $img=imagecreatefromjpeg("image.png"); imageconvolution($img,array(array(-1,-1,-1),array(-1,16,-1),array(-1,-1, -1)), 8,0); imagejpeg($img,"test.png"); ?> Expected result: ---------------- A sharpened image with intact alpha channel, alternavly sharpened alpha channel Actual result: -------------- Image is flattened against black background even if the color data of the background indicates it should be white. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=34992&edit=1