Imagick::blackThresholdImage

(PECL imagick 2.0.0)

Imagick::blackThresholdImageForces all pixels below the threshold into black

설명

bool Imagick::blackThresholdImage ( mixed $threshold )

Is like Imagick::thresholdImage() but forces all pixels below the threshold into black while leaving all pixels above the threshold unchanged.

인수

threshold

The threshold below which everything turns black

반환값

성공시에 TRUE를 반환합니다.

변경점

버전 설명
2.1.0 Now allows a string representing the color as a parameter. Previous versions allow only an ImagickPixel object.

예제

Example #1 Imagick::blackThresholdImage()

<?php
function blackThresholdImage($imagePath$thresholdColor) {
    
$imagick = new \Imagick(realpath($imagePath));
    
$imagick->blackthresholdimage($thresholdColor);
    
header("Content-Type: image/jpg");
    echo 
$imagick->getImageBlob();
}

?>

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User Contributed Notes 2 notes

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2
Iddles
13 years ago
You need to pass this function a colour:

<?php

$img
->blackThresholdImage( "#FFFFFF" );

?>

E.g. this blackens any pixel which isn't pure white.
up
1
elmer at web-axis dot net
15 years ago
Here's a example of this function:

<?php
  $img
= new Imagick();
 
$img->readImage($image_file_name);
 
$img->blackThresholdImage('grey');
 
$img->writeImage($thumb_file_name);
 
$img->clear();
 
$img->destroy();
?>
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