imagesavealpha
Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images
Description
bool imagesavealpha
( resource $image
, bool $saveflag
)
You have to unset alphablending
(imagealphablending($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 compliant
browser, e.g. latest Mozilla.
Parameters
-
image -
An image resource, returned by one of the image creation functions,
such as imagecreatetruecolor.
-
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 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).