@Override
    public Dimension getImageSize(final ByteSource byteSource, final IcnsImagingParameters params) throws ImagingException, IOException {
        final IcnsContents contents = readImage(byteSource);
        final List<BufferedImage> images = IcnsDecoder.decodeAllImages(contents.icnsElements);
        if (images.isEmpty()) {
            throw new ImagingException("No icons in ICNS file");
        }
        final BufferedImage image0 = images.get(0);
        return new Dimension(image0.getWidth(), image0.getHeight());
    }
Constructs a new instance with the big-endian byte order.
src/main/java/org/apache/commons/imaging/formats/icns/IcnsImageParser.java