Source

File: wp-includes/class-wp-image-editor-imagick.php

public static function test( $args = array() ) {

		// First, test Imagick's extension and classes.
		if ( ! extension_loaded( 'imagick' ) || ! class_exists( 'Imagick', false ) || ! class_exists( 'ImagickPixel', false ) ) {
			return false;
		}

		if ( version_compare( phpversion( 'imagick' ), '2.2.0', '<' ) ) {
			return false;
		}

		$required_methods = array(
			'clear',
			'destroy',
			'valid',
			'getimage',
			'writeimage',
			'getimageblob',
			'getimagegeometry',
			'getimageformat',
			'setimageformat',
			'setimagecompression',
			'setimagecompressionquality',
			'setimagepage',
			'setoption',
			'scaleimage',
			'cropimage',
			'rotateimage',
			'flipimage',
			'flopimage',
			'readimage',
		);

		// Now, test for deep requirements within Imagick.
		if ( ! defined( 'imagick::COMPRESSION_JPEG' ) ) {
			return false;
		}

		$class_methods = array_map( 'strtolower', get_class_methods( 'Imagick' ) );
		if ( array_diff( $required_methods, $class_methods ) ) {
			return false;
		}

		return true;
	}