ID: 34992
Comment by: jcolby at remove dot this dot acsol dot net
Reported By: jaanus at underwerks dot com
Status: Assigned
Bug Type: GD related
Operating System: Linux 2.6.13
PHP Version: 6CVS-2005-10-26 (snap)
Assigned To: pajoye
New Comment:
The fix to this:
In reference functions I manged to pinpoint a duplicate problem and
solution, the destination resource image internal to the
imageconvolution function needs to have the imagesavealpha flag set to
true or equivalent after creation. Thats all this needs to be resolved.
imagesavealpha($resource, true);
Previous Comments:
------------------------------------------------------------------------
[2007-10-30 07:50:19] michael dot buckley at ozemail dot coml dot au
I am trying to make slightly blurred drop shadows for some text, but
since I then need to layer it over the top of another image it needs to
keep the alpha layer.
Right now I am using a color to alpha function to undo this effect, but
it is slow.
Any one working on this?
------------------------------------------------------------------------
[2007-08-06 10:01:48] paj...@php.net
By the way, I suppose it is a typo but you are using the jpeg functions
to load and save PNG. It is not going to work (and jpeg has no alpha
support).
"This bug still occurs with 5.2.2 which is fairly new."
What make you think that anything has changed regarding this behavior?
In the meantime, I figured out the source of the problem. Feedback >
open.
------------------------------------------------------------------------
[2007-08-06 09:32:34] ghosh at q-one dot com
This bug still occurs with 5.2.2 which is fairly new. Can't test 5.2.3
right now but it doesnt mention anything about imageconvolution in the
changelog so I believe this is still unfixed.
The original post about "background color" is a little bit misleading.
To put it more simply: Any alpha channel information simply gets
destroyed when using imageconvolution. An example image isnt really
necessary because it happens with ANY png with alpha channel. I can
provide one on request if absolutely necessary though.
Use cases? For instance I have a dynamically generated price tag here
as alpha png. I rotate it with imagerotate. Rotation makes it somewhat
blurry. So afterwards I try sharpening it with imageconvolution. There
you go: Alpha channel info goes down the drain...
------------------------------------------------------------------------
[2005-11-03 01:00:07] php-bugs at lists dot php dot net
No feedback was provided for this bug for over a week, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
------------------------------------------------------------------------
[2005-10-26 14:52:28] paj...@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.
------------------------------------------------------------------------
The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
http://bugs.php.net/34992
--
Edit this bug report at http://bugs.php.net/?id=34992&edit=1
