@Override
	public String getWarningOrError() {
		if (lastInfo == null) {
			return null;
		}
		final double actualWidth = lastInfo.getWidth();
		if (actualWidth == 0) {
			return null;
		}
		final String value = getSkinParam().getValue("widthwarning");
		if (value == null) {
			return null;
		}
		if (value.matches("\\d+") == false) {
			return null;
		}
		final int widthwarning = Integer.parseInt(value);
		if (actualWidth > widthwarning) {
			return "The image is " + ((int) actualWidth) + " pixel width. (Warning limit is " + widthwarning + ")";
		}
		return null;
	}