Point Cloud Reconstruction From Disparity Map Not Working

Hi,

So I have two images that I have created a disparity map and then point cloud with. However, this is far from the shape of the actual object. The disparity map is pretty accurate, however this is not. Does this have to do with the camera calibration? Additionally, the point cloud seems piece-wise. Is this how its supposed to be?

Answer 1

[Dima Lisin]

Hi David,

Can you please post your disparity map and the stereoParameters object? Also, it would help if you could post the images.

Off the top of my head, I would try restricting the range of the Z-coordinates. In other words, exclude the points where Z is negative or too large from the point cloud. It may well be that the point cloud you are seeing is dominated by noise.

Also, check if camera 1 is on the left or on the right, as you look in the same direction as the cameras.

[Munin]

@Dima Lisin I've attached a reproduction of the issue:

Here's a bulletproof workaround:

stereo2stl/script.m at v1.5.0 · SNDST00M/stereo2stl (github.com)

Answer 2

[Munin]

I made a support ticket for it because I found this during my dissertation. It is not considered a bug by the MathWorks team as the point cloud has the same number of points as the original disparity map, despite being 1000x the scale of the world scene.

Workaround: https://github.com/SNDST00M/stereo2stl/blob/v1.5.0/script.m#L216-L380