php 한글 메뉴얼 도움말 검색 사이트 Applies an expression to an image [imagick.evaluateimage]

설명

bool Imagick::evaluateImage ( int $op , float $constant [, int $channel = Imagick::CHANNEL_ALL ] )

Applys an arithmetic, relational, or logical expression to an image. Use these operators to lighten or darken an image, to increase or decrease contrast in an image, or to produce the "negative" of an image.

인수

op: The evaluation operator
constant: The value of the operator
channel: Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Refer to this list of channel constants.

예제

Example #1 Using Imagick::evaluateImage()

Using evaluateImage to reduce opacity in an image.


<?php
// Create new object with the image
$im = new Imagick('example-alpha.png');

// Reduce the alpha by 50%
$im->evaluateImage(Imagick::EVALUATE_DIVIDE, 2, Imagick::CHANNEL_ALPHA);

// Output the image
header("Content-Type: image/png");
echo $im;
?>

반환값

성공시에 TRUE를 반환합니다.

오류/예외

오류시에 ImagickException이 발생합니다.