openCV Disparity Map Ghosting

Hi all I have a little issue I’m trying to track down. I think I’m getting there with stereo vision / disparity map / point cloud generation but I seem to have hit a potential problem. Im using openFrameworks to generate the images from video and show the point cloud. I know a few people here play with stereo setups so I wonder if anyone has had the ghosting problem I seem to have?

http://farm8.staticflickr.com/7242/6871093334-b93e6c4abd-o.png

In this image, you can see that my thumb is duplicated. There is a slight ghosting to the left in the picture. I’ve circled ‘both thumbs’ in red. Now it appears that I have the right depth in most cases - the hand is definitely closer to the screen than the rest and I’ve checked over the code. Im using opencv to calibrate the cameras, using the latest opencv from SVN. Im using the stereo_calib example to generate the intrinsic and extrinsic parameters and the rectified images. They seem pretty good - 0.9 RMS Error and 1.4 on the reproduction error. I take these and place them into this OpenFrameworks app and use the Stereo_BM GPU algorithm to generate the disparity map. I have settings for the block matching and the disparity levels. I think im close but the duplication is a concern. I can understand why holes occur but it seems a little odd to get this kind of ghosting.

Cheers

Ben

Hey ben

I am working in a stereo vision project and I am having the same “ghost” problem (like yours, in the left side). I am using the StereoSGBM with 2 calibrated ps3eye cameras in ubuntu.

Have you found the solution for this?