public String getMimeType() {
        if (format >= 0 && format < MIME_TYPE_STRINGS.length) {
            if (format == FORMAT_JPEG && progressive) {
                return "image/pjpeg";
            }
            return MIME_TYPE_STRINGS[format];
        }
        return null;
    }
public String getMimeType ( ) { if ( format >= 0 && format < MIME_TYPE_STRINGS . length ) { if ( format == FORMAT_JPEG && progressive ) { return "image/pjpeg" ; } return MIME_TYPE_STRINGS [ format ] ; } return null ; }
If {@link #check()} was successful, returns a String with the MIME type of the format.

@return MIME type, e.g. <code>image/jpeg</code>