imagesavealpha

(PHP 4 >= 4.3.2, PHP 5, PHP 7)

imagesavealpha — Set the flag to save full alpha channel information (as opposed to single-color transparency) when saving PNG images

설명

bool imagesavealpha ( resource $image , bool $saveflag )

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.

인수

image: imagecreatetruecolor() 등의 이미지 생성 함수에서 반환한 이미지 자원.
saveflag: Whether to save the alpha channel or not. Default to FALSE.

반환값

성공 시 TRUE를, 실패 시 FALSE를 반환합니다.

예제

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);
?>

주의

Note: 이 함수는 GD 2.0.1 이후 버전이 필요합니다. (2.0.28 이후를 권장합니다)

참고

imagealphablending() - Set the blending mode for an image