imagecolorexactalpha

(PHP 4 >= 4.0.6, PHP 5)

imagecolorexactalpha -- 取得指定的颜色加透明度的索引值

说明

int imagecolorexactalpha ( resource image, int red, int green, int blue, int alpha )

返回图像调色板中指定颜色加透明度的索引值。

如果颜色不在图像的调色板中,返回 -1。 returned.

注: 本函数需要 GD 2.0.1 或更高版本。

参见 imagecolorclosestalpha()


add a note add a note User Contributed Notes
matt at matt-darby dot com
12-Jul-2005 09:09
Note that a color allocated with imagecolorexactalpha won't show alpha (it will be opaque) when used with imageline(). Use imagerectangle() set to your normal start and end points instead.

Ensure that the image is created via imagecreatetruecolor() as well!
phpdoc-comment at aditus dot nu
09-Nov-2002 02:01
What might be misleading in the docs is that if the specified color + alpha channel does not exist it will be created. So if you like to use an alpha channel in your image enable alpha blending and then create you color using this method.