imagecolortransparent
(PHP 4, PHP 5, PHP 7, PHP 8)
Define a color as transparent
Description
Gets or sets the transparent color in the given image.
Parameters
colorColor
Return Values
The identifier of the new (or current, if none is specified) transparent color is returned. If color is null, and the image has no transparent color, the returned identifier will be -1.
Changelog
| Version | Description |
|---|---|
| 8.0.0 | color is now nullable. |
Examples
imagecolortransparent() example
<?php
// Create a 55x30 image
$im = imagecreatetruecolor(55, 30);
$red = imagecolorallocate($im, 255, 0, 0);
$black = imagecolorallocate($im, 0, 0, 0);
// Make the background transparent
imagecolortransparent($im, $black);
// Draw a red rectangle
imagefilledrectangle($im, 4, 4, 50, 25, $red);
// Save the image
imagepng($im, './imagecolortransparent.png');
?>The above example will output something similar to: Output of example : imagecolortransparent()
Notes
Transparency is copied only with imagecopymerge() and true color images, not with imagecopy() or palette images.
The transparent color is a property of the image, transparency is not a property of the color. Once you have set a color to be the transparent color, any regions of the image in that color that were drawn previously will be transparent.