IMAGESAVEALPHA(3) 1 IMAGESAVEALPHA(3)
imagesavealpha - Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images
SYNOPSIS
bool imagesavealpha (resource $image, bool $saveflag)
DESCRIPTION
imagesavealpha(3) sets the flag to attempt to save full alpha channel information (as opposed to single-color transparency) when saving PNG
images.
You have to unset alphablending ( imagealphablending($im, false)), to use it.
Alpha channel is not supported by all browsers, if you have problem with your browser, try to load your script with an alpha channel com-
pliant browser, e.g. latest Mozilla.
PARAMETERS
o $
image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).
o $saveflag
- Whether to save the alpha channel or not. Default to FALSE.
RETURN VALUES
Returns TRUE on success or FALSE on failure.
EXAMPLES
Example #1
imagesavealpha(3) example
<?php
// Load a png image with alpha channels
$png = imagecreatefrompng('./alphachannel_example.png');
// Do required operations
// Turn off alpha blending and set alpha flag
imagealphablending($png, false);
imagesavealpha($png, true);
// Output image to browser
header('Content-Type: image/png');
imagepng($png);
imagedestroy($png);
?>
NOTES
Note
This function requires GD 2.0.1 or later (2.0.28 or later is recommended).
SEE ALSO
imagealphablending(3).
PHP Documentation Group IMAGESAVEALPHA(3)
