FastImage::parseSize PHP Method

    private function parseSize()
    {
        $this->strpos = 0;
        switch ($this->type) {
            case 'png':
                return $this->parseSizeForPNG();
            case 'gif':
                return $this->parseSizeForGIF();
            case 'bmp':
                return $this->parseSizeForBMP();
            case 'jpeg':
                return $this->parseSizeForJPEG();
        }
        return null;
    }