Stereo Depth

Key Insight

A single camera cannot see depth, but two cameras a known distance apart can — exactly how your two eyes do it. The same object appears shifted sideways between the left and right images, and that shift, called disparity, is large for near objects and small for far ones. Stereo vision measures the disparity for every pixel and converts it to distance by triangulation — intersecting the two lines of sight in 3D — producing a depth map you can lift into a point cloud. The catch this project teaches: depth precision falls off with the square of distance, so a rig accurate to a millimeter up close may be off by centimeters across the room.