Replacing
imagecopymerge($im, $wm, $dest_x, $dest_y, 0, 0, $wm_x, $wm_y, $percentage)
with
imagecopy($im, $wm, $dest_x, $dest_y, 0, 0, $wm_x, $wm_y)
in _watermark_process() function allows to use PNG-24 watermarks with advanced transparency.

Example: http://www.ladygin.ru/files/images/IMG_4714.jpg

Comments

enky’s picture

enky commented
Priority: Normal » Critical

thanks Nilard, it works, cool,

kbahey’s picture

kbahey commented

Nilard and enky4u

Can you test that this is backward compatible with PNG- ?

if it is i will include this patch in the base module.

nilard’s picture

nilard commented

Yes, it's compatible to PNG-8.
Take a look at the comments for http://php.net/imagecopymerge
i found that if you use imagecopymerge with png-24 files with an alpha channel, it doesn't work use imagecopy instead.
it seems that imagecopymerge doesn't respect the alpha channel the way it should (a bug??).

kbahey’s picture

kbahey commented
Title: imagecopymerge VS imagecopy » Use imagecopy instead of imagecopymerge to preserve PNG-24 transparency
Priority: Critical » Normal
Status: Active » Fixed

Applied to 4.7 and HEAD.

nilard’s picture

nilard commented

Don't forget that 'Percentage' option (for alpha blending) in admin/settings/image -> Watermark is obsolete now.

kbahey’s picture

kbahey commented

It is already removed by that fix, since it has no meaning anymore.

Anonymous’s picture

(not verified) commented
Status: Fixed » Closed (fixed)