Decrease noise in Disparity map

Question

I calculated Disparity map in c# (Emgu). The attached file1 is left and right image, and disparity map. The noise of disparity map is high. How can i decrease noise in disparity map? Thanks.

Answer 1

If you want better result in disparity map you should have good camera calibration. The more accurate camera calibration lead to more accurate disparity map.

Answer 2

As tiziran pointed out, good (stereo) calibration is important. Since you usually calibrate each camera retrieving its whole projection matrix, it's difficult to say which of its parameters is the most important.

Stereo calibration involves also the determination of the rotation and traslation of the second camera with respect to the first camera.

In your case, some other things have to be considered:

A) in general noise depends on window correlation size and on the correlation method. Several method exists. The bigger the correlation size, the lower the noise but also the lower the precision.

B) To have disparity, points have to be seen from both your cameras. Half of each image is out the field of view of the other camera, so it would be useless (and tipically noise occurs in areas where disparity couldn't be computated). I think in this case there is too much distance / rotation between the cameras (it does not helps).

C) It is hard to have good disparity where there is no texture at all, or where the texture dimension is too bigger than the correlation window size. In your images there are zones with uniform white color and no texture

D) I think that is hard to have good disparity where the carpet is out of focus. It is my personal consideration but this fact does not help you for sure.