code: public short getPixelValue(WritableRaster raster, int x, int y) {
  		Object pixelData = raster.getDataElements(x, y, null);
  		short sdata[] = (short[]) pixelData;
  		if (sdata.length != 1) {
  			throw new UnsupportedOperationException(
  					"This method is not supported by this color model");
  		}
  		short pixelValue = sdata[0];
  
  		return pixelValue;
  	}
docs: Get the pixel value as an "unsigned short" from the raster and the
  coordinate
  
  @param raster
  image raster
  @param x
  x coordinate
  @param y
  y coordinate
  @return "unsigned short" pixel value