Php/docs/function.imagesavealpha
imagesavealpha
(PHP 4 >= 4.3.2, PHP 5, PHP 7)
imagesavealpha — Whether to retain full alpha channel information when saving PNG images
Description
imagesavealpha
( resource $image
, bool $saveflag
) : bool
imagesavealpha() sets the flag which determines whether to retain full alpha channel information (as opposed to single-color transparency) when saving PNG images.
Alphablending has to be disabled (imagealphablending($im, false))
to retain the alpha-channel in the first place.
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. Defaults to
FALSE.
Return Values
Returns TRUE on success or FALSE on failure.
Examples
Example #1 Basic imagesavealpha() Usage
<?php// Load a png image with alpha channel$png = imagecreatefrompng('./alphachannel_example.png');// Turn off alpha blendingimagealphablending($png, false);// Do desired operations// Set alpha flagimagesavealpha($png, true);// Output image to browserheader('Content-Type: image/png');imagepng($png);imagedestroy($png);?>
