/** Reads the image header.
 * Does nothing if the header has already been loaded.
 */
private void readHeader() throws IOException {
    if (image == null) {
        ImageReader r = new JPEGImageReader(getOriginatingProvider());
        Object in = getInput();
        /*if (in instanceof Buffer) {
            Buffer buffer = (Buffer) in;
            in=buffer.getData();
        }*/
        if (in instanceof byte[]) {
            r.setInput(new MemoryCacheImageInputStream(AVIBMPDIB.prependDHTSeg((byte[]) in)));
        } else if (in instanceof ImageInputStream) {
            r.setInput(AVIBMPDIB.prependDHTSeg((ImageInputStream) in));
        } else {
            r.setInput(AVIBMPDIB.prependDHTSeg((InputStream) in));
        }
        image = r.read(0);
    }
}
 

private static ImageReader createNativeJPEGReader() {
    return new JPEGImageReader(new CMYKJPEGImageReaderSpi());
    /*
     for (Iterator<ImageReader> i =
     ImageIO.getImageReadersByFormatName("jpeg"); i.hasNext();) {
     ImageReader r = i.next();
     if (!(r instanceof CMYKJPEGImageReader)
     && !r.getClass().getName().contains("CMYKJPEGImageReader")) {
     return r;
     }
     }
    
     return null;
     * 
     */
}
 

public static void main(String[] args) throws IOException {
    ImageReader gifReader = new GIFImageReader(null);
    ImageReader jpegReader = new JPEGImageReader(null);
    ImageReader pngReader = new PNGImageReader(null);

    test(gifReader, "GIF");
    test(jpegReader, "JPEG");
    test(pngReader, "PNG");
}
 

public static void main(String[] args) throws IOException {
    ImageReader gifReader = new GIFImageReader(null);
    ImageReader jpegReader = new JPEGImageReader(null);
    ImageReader pngReader = new PNGImageReader(null);

    test(gifReader, "GIF");
    test(jpegReader, "JPEG");
    test(pngReader, "PNG");
}