lib/ImageHelper.php
public static function retina_resize( $src, $multiplier = 2, $force = false ) {
		$op = new Image\Operation\Retina($multiplier);
		return self::_operate($src, $op, $force);
	}
public static function retina_resize( $src, $multiplier = 2, $force = false ) {
		$op = new Image\Operation\Retina($multiplier);
		return self::_operate($src, $op, $force);
	}
public static function retina_resize ( $ src , $ multiplier = 2 , $ force = false ) { $ op = new Image \ Operation \ Retina ( $ multiplier ) ; return self :: _operate ( $ src , $ op , $ force ) ; }
Generates a new image with increased size, for display on Retina screens.

@param string  $src
@param float   $multiplier
@param boolean $force

@return string url to the new image
Generates a new image with increased size for display on Retina screens .