Efficient 3-D telestration for local robotic proctoring

An apparatus to show three-dimensional telestration a user, the apparatus comprising:

• a source of stereo images, each stereo image comprising a first image and a second image;
• a stereo display comprising a first display and a second display respectively presenting the first image and the second image in three-dimensional appearance to the user;
• a second user display presenting the first image to a second user;
• a second user input device configured to receive input from the second user to draw first telestration marks on the first image shown on the second user display;
• and
• a processor system configured to receive the input from the second user input device;
• identify selected points of interest corresponding to the first telestration marks;
• selectively match the selected points of interest to points of the second image to determine matched points of interest of the second image by computing a plurality of image offsets wherein each of the plurality of image offsets is computed using a different image matching method than all others of the plurality of image offsets, and by using one of the computed plurality of image offsets which is selected according at least partially to one or more confidence scores of the plurality of image offsets, wherein the matched points of interest correspond to second telestration marks;
• and cause the first and second telestration marks to be displayed on the stereo display such that the first telestration marks and the second telestration marks appear in three dimensions to the first user.