PHP Manual: Separates a channel from the image

Description

public bool Imagick::separateImageChannel(int $channel)

Separates a channel from the image and returns a grayscale image. A channel is a particular color component of each pixel in the image.

Parameters

channel: Which 'channel' to return. For colorspaces other than RGB, you can still use the CHANNEL_RED, CHANNEL_GREEN, CHANNEL_BLUE constants to indicate the 1st, 2nd and 3rd channels.

Return Values

Returns true on success.

Errors/Exceptions

Throws ImagickException on error.

Examples

Example #1 Imagick::separateImageChannel

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

separateImageChannel($imagePath, \Imagick::CHANNEL_GREEN);

?>