lib/ImageHelper.php
public static function letterbox( $src, $w, $h, $color = false, $force = false ) {
		$op = new Letterbox($w, $h, $color);
		return self::_operate($src, $op, $force);
	}
public static function letterbox( $src, $w, $h, $color = false, $force = false ) {
		$op = new Letterbox($w, $h, $color);
		return self::_operate($src, $op, $force);
	}
public static function letterbox ( $ src , $ w , $ h , $ color = false , $ force = false ) { $ op = new Letterbox ( $ w , $ h , $ color ) ; return self :: _operate ( $ src , $ op , $ force ) ; }
Generate a new image with the specified dimensions.
New dimensions are achieved by adding colored bands to maintain ratio.

@param string  $src
@param int     $w
@param int     $h
@param string  $color
@param bool    $force
@return string
Generate a new image with the specified dimensions . New dimensions are achieved by adding colored bands to maintain ratio .