code: public static void rectifyHToAbsoluteQuadratic(DMatrixRMaj H , DMatrixRMaj Q ) {
  		int indexQ = 0;
  		for (int rowA = 0; rowA < 4; rowA++) {
  			for (int colB = 0; colB < 4; colB++) {
  				int indexA = rowA*4;
  				int indexB = colB*4;
  				double sum = 0;
  
  				for (int i = 0; i < 3; i++) {
  //					sum += H.get(rowA,i)*H.get(colB,i);
  					sum += H.data[indexA++]*H.data[indexB++];
  				}
  
  //				Q.set(rowA,colB,sum);
  				Q.data[indexQ++] = sum;
  			}
  		}
  	}
docs: Rectifying homography to dual absolute quadratic.
  
  <p>Q = H*I*H<sup>T</sup> = H(:,1:3)*H(:,1:3)'</p>
  <p>where I = diag(1 1 1 0)</p>
  
  @param H (Input) 4x4 rectifying homography.
  @param Q (Output) Absolute quadratic. Typically found in auto calibration. Not modified.