imagesavealpha

Description
Syntax
Examples
Links

Description

The imagesavealpha of Image for PHP whether to retain full alpha channel information when saving images.

Syntax

imagesavealpha(
    GdImage $image,
    bool $enable
): bool

Parameters

image

A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

enable

Whether to save the alpha channel or not. Defaults to false.

Return

Returns true on success or false on failure.

Examples

1 · return

<?

$width = 100;
$height = 100;
$image = imagecreate($width, $height);

$enable = true;

$return = imagesavealpha($image, $enable);

var_export($return);

true

2 · base64 · enable · false

<?

$width = 100;
$height = 100;
$image = imagecreatetruecolor($width, $height);

$enable = false;
imagesavealpha($image, $enable);

$red = 0;
$green = 0;
$blue = 0;
$alpha = 64;
$color = imagecolorallocatealpha($image, $red, $green, $blue, $alpha);

$x = 0;
$y = 0;
imagefill($image, $x, $y, $color);

ob_start();

    imagepng($image);

$output = ob_get_clean();

echo '<!doctype html>
<html>
<body>
    <img src="data:image/png;base64,' . base64_encode($output) . '">
</body>
</html>';

<!doctype html>
<html>
<body>
    <img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAGQAAABkCAIAAAD/gAIDAAAACXBIWXMAAA7EAAAOxAGVKw4bAAAANElEQVR4nO3BAQ0AAADCoPdPbQ43oAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAfgx1lAABqFDyOQAAAABJRU5ErkJggg==">
</body>
</html>

3 · base64 · enable · true

<?

$width = 100;
$height = 100;
$image = imagecreatetruecolor($width, $height);

$enable = true;
imagesavealpha($image, $enable);

$red = 0;
$green = 0;
$blue = 0;
$alpha = 64;
$color = imagecolorallocatealpha($image, $red, $green, $blue, $alpha);

$x = 0;
$y = 0;
imagefill($image, $x, $y, $color);

ob_start();

    imagepng($image);

$output = ob_get_clean();

echo '<!doctype html>
<html>
<body>
    <img src="data:image/png;base64,' . base64_encode($output) . '">
</body>
</html>';

<!doctype html>
<html>
<body>
    <img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAGQAAABkCAYAAABw4pVUAAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAElEQVR4nO3RQQ0AIBDAsAPhaOeNAvZoFSzZmpkzZOzfAbwMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEkxpAYQ2IMiTEk5gLrigFGs/uyPgAAAABJRU5ErkJggg==">
</body>
</html>