Then, they will transform the skin to the exact location of the laser marks. This registration has six degrees of freedom. With a rough initial transformation, the laser points are overlaid. The process iterates until a sufficiently accurate solution is found. Now, they calibrate the pose of the camera, which is positioned over the shoulder of the surgeon, relative to the laser data.
Calibration is done by matching features in the laser data and image data, tracking fiducial marks.
Finally, the MRI data is transformed via the laser data to the camera position. The camera image and the graphical model are mixed. The camera is in camera space, the laser data is in the coordinates of the patient. During the final mix the MRI data and the camera image are blended on the monitor. The current method hasn't dealt with perspective yet, so the depth where the tumor is located is currently unknown.