changed overlay_watermark() to check for an alpha value before applying the image to help support PNG-24s with alpha transparency
http://codeigniter.com/bug_tracker/bug/4506/
diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 0750b64..4017afb 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -943,10 +943,23 @@
{
@imagealphablending($src_img, TRUE);
}
-
- // Set RGB values for text and shadow
- imagecolortransparent($wm_img, imagecolorat($wm_img, $this->wm_x_transp, $this->wm_y_transp));
- imagecopymerge($src_img, $wm_img, $x_axis, $y_axis, 0, 0, $wm_width, $wm_height, $this->wm_opacity);
+
+ // Set RGB values for text and shadow
+ $rgba = imagecolorat($wm_img, $this->wm_x_transp, $this->wm_y_transp);
+ $alpha = ($rgba & 0x7F000000) >> 24;
+
+ // make a best guess as to whether we're dealing with an image with alpha transparency or no/binary transparency
+ if ($alpha > 0)
+ {
+ // copy the image directly, the image's alpha transparency being the sole determinant of blending
+ imagecopy($src_img, $wm_img, $x_axis, $y_axis, 0, 0, $wm_width, $wm_height);
+ }
+ else
+ {
+ // set our RGB value from above to be transparent and merge the images with the specified opacity
+ imagecolortransparent($wm_img, imagecolorat($wm_img, $this->wm_x_transp, $this->wm_y_transp));
+ imagecopymerge($src_img, $wm_img, $x_axis, $y_axis, 0, 0, $wm_width, $wm_height, $this->wm_opacity);
+ }
// Output the image
if ($this->dynamic_output == TRUE)
@@ -1533,6 +1546,6 @@
}
// END Image_lib Class
-
-/* End of file Image_lib.php */
+
+/* End of file Image_lib.php */
/* Location: ./system/libraries/Image_lib.php */
\ No newline at end of file