Disparity map vs depth map

Disparity is the horizontal displacement of a point's projections between the left and the right image. Whereas, depth refers to the z coordinate (usually z) of a point located in the real 3D world (x, y, z).

1. What is disparity map?
2. What is disparity in depth estimation?
3. How do you find the depth of a disparity map?
4. Is depth proportional to disparity?

What is disparity map?

Disparity map refers to the apparent pixel difference or motion between a pair of stereo images. To experience this, try closing one of your eyes and then rapidly close it while opening the other. Objects that are close to you will appear to jump a significant distance while objects further away will move very little.

What is disparity in depth estimation?

Stereo matching or disparity estimation is the process of finding the pixels in the multiscopic views that correspond to the same 3D point in the scene. The rectified epipolar geometry simplifies this process of finding correspondences on the same epipolar line.

How do you find the depth of a disparity map?

x = xl*z/f or b + xr*z/f y = yl*z/f or yr*z/f This method of determining depth from disparity d is called triangulation.

Is depth proportional to disparity?

Depth is inversely proportional to disparity, thus measurements are limited to nearby objects.