(PHP 4 >= 4.3.2, PHP 5)
imagesavealpha — Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images
imagesavealpha() 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 compliant browser, e.g. latest Mozilla.
Ресурс на изображение, върнат от някоя от функциите за създаване на изображения като например imagecreatetruecolor().
Whether to save the alpha channel or not. Default to FALSE.
Връща TRUE при успех или FALSE при неуспех.
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);
?>
Забележка: Тази функция изисква GD 2.0.1 или по-нова (препоръчва се 2.0.28 или по-нова).