IMAGECOLORTRANSPARENT(3) 1 IMAGECOLORTRANSPARENT(3)
imagecolortransparent - Define a color as transparent
SYNOPSIS
int imagecolortransparent (resource $image, [int $color])
DESCRIPTION
Sets the transparent color in the given $image.
PARAMETERS
o $
image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).
o $color
- A color identifier created with imagecolorallocate(3).
RETURN VALUES
The identifier of the new (or current, if none is specified) transparent color is returned. If $color is not specified, and the image has
no transparent color, the returned identifier will be -1.
EXAMPLES
Example #1
imagecolortransparent(3) 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:[NOT DISPLAYABLE MEDIA]Output of example : imagecolortransparent()
NOTES
Note
Transparency is copied only with imagecopymerge(3) and true color images, not with imagecopy(3) 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.
PHP Documentation Group IMAGECOLORTRANSPARENT(3)