Note that a color allocated with imagecolorexactalpha won't show alpha (it will be opaque) when used with imageline(). Use imagerectangle() set to your normal start and end points instead.
Ensure that the image is created via imagecreatetruecolor() as well!
imagecolorexactalpha
(PHP 4 >= 4.0.6, PHP 5, PHP 7)
imagecolorexactalpha — Get the index of the specified color + alpha
설명
int imagecolorexactalpha
( resource
$image
, int $red
, int $green
, int $blue
, int $alpha
)Returns the index of the specified color+alpha in the palette of the image.
인수
-
image -
imagecreatetruecolor() 등의 이미지 생성 함수에서 반환한 이미지 자원.
-
red -
Red 컴포넌트 값.
-
green -
Green 컴포넌트 값.
-
blue -
Blue 컴포넌트 값.
-
alpha -
A value between 0 and 127. 0 indicates completely opaque while 127 indicates completely transparent.
반환값
Returns the index of the specified color+alpha in the palette of the image, or -1 if the color does not exist in the image's palette.
예제
Example #1 Get colors from the GD logo
<?php
// Setup an image
$im = imagecreatefrompng('./gdlogo.png');
$colors = Array();
$colors[] = imagecolorexactalpha($im, 255, 0, 0, 0);
$colors[] = imagecolorexactalpha($im, 0, 0, 0, 127);
$colors[] = imagecolorexactalpha($im, 255, 255, 255, 55);
$colors[] = imagecolorexactalpha($im, 100, 255, 52, 20);
print_r($colors);
// Free from memory
imagedestroy($im);
?>
위 예제의 출력 예시:
Array
(
[0] => 16711680
[1] => 2130706432
[2] => 939524095
[3] => 342163252
)
add a note
User Contributed Notes 2 notes
matt at matt-darby dot com ¶
18 years ago
phpdoc-comment at aditus dot nu ¶
21 years ago
What might be misleading in the docs is that if the specified color + alpha channel does not exist it will be created. So if you like to use an alpha channel in your image enable alpha blending and then create you color using this method.
