code: protected Double getBilinearInterpolationValue(float offsetX,
  			float offsetY, float minX, float maxX, float minY, float maxY,
  			Double[][] values) {
  
  		Double value = null;
  
  		if (values != null) {
  			value = getBilinearInterpolationValue(offsetX, offsetY, minX, maxX,
  					minY, maxY, values[0][0], values[0][1], values[1][0],
  					values[1][1]);
  		}
  
  		return value;
  	}
docs: Get the Bilinear Interpolation coverage data value
  
  @param offsetX
  x source pixel offset
  @param offsetY
  y source pixel offset
  @param minX
  min x value
  @param maxX
  max x value
  @param minY
  min y value
  @param maxY
  max y value
  @param values
  2 x 2 coverage data values as [y][x]
  @return coverage data value