PHP | Imagick blackThresholdImage() Function

The Imagick::blackThresholdImage() function is an inbuilt function in PHP which forces all pixels below the threshold value into black while leaving all pixels above the threshold unchanged.

Syntax:

bool Imagick::blackThresholdImage( $threshold )

Parameters: This function accepts a single parameter $threshold which is mandatory. All the pixel value below threshold value which everything turns black.

Return Value: This function returns True on success.

Below program illustrates the Imagick::blackThresholdImage() function in PHP:

Program:

<?php

// Create an Imagick object
$imagick = new Imagick(
'https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-9.png');

// Use blackthresholdimage function
$imagick->blackthresholdimage('rgb(127, 127, 127)');

header("Content-Type: image/jpg");

// Display the output image
echo $imagick->getImageBlob();
?>

Output:

Reference: http://php.net/manual/en/imagick.blackthresholdimage.php