The getQuantumRange is a useful function, since many of the ImageMagick functions accept parameters from 0 to a maximum of the Quantum Range. When getting a return value for this, it doesn't return a string. It actually returns an array, with one type being a String ('quantumRangeLong') and the other type being a Long Int ('quantumRangeString'). Here's some sample code and the results, given a color, BMP file photograph that is 600x450 pixels...
<?php
$imagick_type = new Imagick();
$file_to_grab = "image_workshop_directory/test.bmp";
$file_handle_for_viewing_image_file = fopen($file_to_grab, 'a+');
$imagick_type->readImageFile($file_handle_for_viewing_image_file);
$imagick_type_quantum_range = $imagick_type->getQuantumRange();
print("<pre>");
print_r($imagick_type_quantum_range);
print("</pre>");
?>
Output:
Array
(
[quantumRangeLong] => 65535
[quantumRangeString] => 65535
)