public CanDecodeInputFilter(Object input) 
{
            this.input = input;
}

 public boolean filter(Object elt) 
{
            try {
                ImageReaderSpi spi = (ImageReaderSpi)elt;
                ImageInputStream stream = null;
                if (input instanceof ImageInputStream) {
                    stream = (ImageInputStream)input;
                }
                // Perform mark/reset as a defensive measure
                // even though plug-ins are supposed to take
                // care of it.
                boolean canDecode = false;
                if (stream != null) {
                    stream.mark();
                }
                canDecode = spi.canDecodeInput(input);
                if (stream != null) {
                    stream.reset();
                }
                return canDecode;
            } catch (IOException e) {
                return false;
            }
}