code: public float getPixel(int x, int y) {
  		float pixel = -1;
  		if (rasters == null) {
  			readPixels();
  		}
  		if (rasters != null) {
  			pixel = rasters.getFirstPixelSample(x, y).floatValue();
  		} else {
  			throw new GeoPackageException("Could not retrieve pixel value");
  		}
  		return pixel;
  	}
docs: Get the pixel at the coordinate
  
  @param x
  x coordinate
  @param y
  y coordinate
  @return pixel value