Types
Here are some approaches to measure depth by only using RGB images from motion.
Optical Expansion
Observe how the length of an object changes as the camera moves closer. If the object is close, the length will dramatically change as the camera approaches. If the object is far, the length will only subtly change.
Motion Parallax
Observe how the object’s location shifts as the camera shift sideways.
Challenges
Here are some challenges these approaches face.
- Can’t detect correctly when the object itself is moving.
- Can’t detect correctly when there is a detection error in the bounding box.