(CODE)
<?php

$im = new Imagick( 'example.jpg' );

$im->setImageColorSpace( Imagick::COLORSPACE_GRAY );

header( "Content-Type: image/png" );
echo $im;
 
?>

(ERROR)
Fatal error: Uncaught exception 'ImagickException' with message 'Can not process empty wand.' in /var/www/sites/dtc/irishgrin.com/subdomains/imagemagick/html/imagemanip.php:5 Stack trace: #0 /var/www/sites/dtc/irishgrin.com/subdomains/imagemagick/html/imagemanip.php(5): Imagick->setimagecolorspace(2) #1 {main} thrown in /var/www/sites/dtc/irishgrin.com/subdomains/imagemagick/html/imagemanip.php on line 5