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. Available since 6.2.9
Image
Low threshold
High threshold
Channel
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. Available since 6.2.9
Parameters
lowfloatThe low point
highfloatThe high point
channelintProvide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. Refer to this list of channel constants.
function randomThresholdimage($imagePath, $lowThreshold, $highThreshold, $channel)
{
    $imagick = new \Imagick(realpath($imagePath));

    $imagick->randomThresholdimage(
        $lowThreshold * \Imagick::getQuantum(),
        $highThreshold * \Imagick::getQuantum(),
        $channel
    );
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}