PHP | Imagick setImageChannelDepth() Function

<?php

// Create new Imagick object
$im = new Imagick(
'https://media.geeksforgeeks.org/wp-content/uploads/geeksforgeeks-15.png');

// Using getImageChannelDepth function
// with red channel
echo "Before Set Channel depth: " . "</br>";
echo $im->getImageChannelDepth(imagick::CHANNEL_RED) . "</br>";

// Set channel Depth of CYAN and GREEN Channel
$im->setImageChannelDepth(imagick::CHANNEL_RED, 4);

echo "After Set Channel depth: " . "</br>";
echo $im->getImageChannelDepth(imagick::CHANNEL_RED) . "</br>";
?>

<?php 

$string = "Computer Science portal for Geeks!"; 

// Creating new image of above String 
// and add color
$im = new Imagick(); 
$draw = new ImagickDraw(); 

// Fill the color in image 
$draw->setFillColor(new ImagickPixel('green')); 

// Set the text font size 
$draw->setFontSize(50); 

$metrix = $im->queryFontMetrics($draw, $string); 
$draw->annotation(0, 40, $string); 
$im->newImage($metrix['textWidth'], $metrix['textHeight'], 
        new ImagickPixel('white')); 

// Draw the image         
$im->drawImage($draw); 
$im->setImageFormat('jpeg'); 

// Using getImageChannelDepth function
// with red channel
echo "Before Set Channel depth: " . "</br>";
echo $im->getImageChannelDepth(imagick::CHANNEL_GREEN) . "</br>";

// Set channel Depth of Green Channel
$im->setImageChannelDepth(imagick::CHANNEL_GREEN, 8);

echo "After Set Channel depth: " . "</br>";
echo $im->getImageChannelDepth(imagick::CHANNEL_GREEN) . "</br>";
?>