Imagick::thresholdImage

(PECL imagick 2, PECL imagick 3)

Imagick::thresholdImage — Changes the value of individual pixels based on a threshold

说明

public Imagick::thresholdImage(float $threshold, int $channel = Imagick::CHANNEL_DEFAULT): bool

Changes the value of individual pixels based on the intensity of each pixel compared to threshold. The result is a high-contrast, two color image.

参数

threshold
channel

返回值

成功时返回 true。

示例

示例 #1 Imagick::thresholdImage()

<?php
function thresholdimage($imagePath, $threshold, $channel) {
    $imagick = new \Imagick(realpath($imagePath));
    $imagick->thresholdimage($threshold * \Imagick::getQuantum(), $channel);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}

?>

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User Contributed Notes 1 note

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php t traction dot de ¶

12 years ago


getQuantumRange() can be handy here:



<?php

$i = new Imagick($imageFile);

$max = $i->getQuantumRange();

$max = $max["quantumRangeLong"]; 

$i->thresholdImage(0.77 * $max);

?>

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