Imagick::thresholdImage

(PECL imagick 2.0.0)

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

Description

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.

Parameters

threshold
channel

Return Values

Returns TRUE on success.

Examples

Example #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();
}

?>

add a note

User Contributed Notes 1 note

down

php t traction dot de ¶

7 years ago


getQuantumRange() can be handy here:


<?php

$i = new Imagick($imageFile);

$max = $i->getQuantumRange();

$max = $max["quantumRangeLong"]; 

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

?>

add a note