imagecolortransparent

(PHP 4, PHP 5, PHP 7)

imagecolortransparent — Define a color as transparent

설명

int imagecolortransparent ( resource $image [, int $color ] )

Sets the transparent color in the given image.

인수

image: imagecreatetruecolor() 등의 이미지 생성 함수에서 반환한 이미지 자원.
color: A color identifier created with imagecolorallocate().

반환값

The identifier of the new (or current, if none is specified) transparent color is returned. If color is not specified, and the image has no transparent color, the returned identifier will be -1.

예제

Example #1 imagecolortransparent() example


<?php
// Create a 55x30 image
$im = imagecreatetruecolor(55, 30);
$red = imagecolorallocate($im, 255, 0, 0);
$black = imagecolorallocate($im, 0, 0, 0);

// Make the background transparent
imagecolortransparent($im, $black);

// Draw a red rectangle
imagefilledrectangle($im, 4, 4, 50, 25, $red);

// Save the image
imagepng($im, './imagecolortransparent.png');
imagedestroy($im);
?>

위 예제의 출력 예시:

주의

Note:
Transparency is copied only with imagecopymerge() and true color images, not with imagecopy() or pallete images.

Note:
The transparent color is a property of the image, transparency is not a property of the color. Once you have set a color to be the transparent color, any regions of the image in that color that were drawn previously will be transparent.