imagecolortransparent
(PHP 4, PHP 5, PHP 7, PHP 8)
imagecolortransparent — Define a color as transparent
Description
imagecolortransparent(GdImage $image, ?int $color = null): int
Gets or sets the transparent color in the given image
.
Parameters
-
image
-
A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
-
color
-
A color identifier created with imagecolorallocate().
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 | image expects a GdImage instance now; previously, a resource was expected. |
8.0.0 | color is now nullable. |
Examples
Example #1 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'); imagedestroy($im); ?>
The above example will output something similar to:
Notes
Note:
Transparency is copied only with imagecopymerge() and true color images, not with imagecopy() or pallete images.
Note:
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.
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.imagecolortransparent.php