Will disparity map background fuzzy abnormal like rays

Hi, can help to review my disparity map why the noiseness like that?? the red one is my ic chips and im using stereosgbm

your parameters to StereoSGBM need adjustment.

Thansk! i got better result by adjusting the alpha in function stereorectify from -1 to 0.5, if anyone got same problem might try change the alpha

hi btw! if i wants to determine little height difference within mm of the object, anything i should do during calibration to determine the height? like decrease fov or increase DOF