code: public void process(T input, T output) {
  
  		this.output = FactoryGImageGray.wrap(output,this.output);
  		interp.setImage(input);
  
  		int indexMap = 0;
  		for( int i = 0; i < output.height; i++ ) {
  			int indexOut = output.startIndex + i*output.stride;
  			for( int j = 0; j < output.width; j++ , indexOut++,indexMap++ ) {
  				Point2D_F32 p = mapPixels[indexMap];
  				if( p != null ) {
  					this.output.set(indexOut,interp.get( p.x, p.y));
  				}
  			}
  		}
  	}
docs: Computes overhead view of input image.  All pixels in input image are assumed to be on the ground plane.
  
  @param input (Input) Camera image.
  @param output (Output) Image containing overhead view.