Using low cost stereo cameras

[patrickelectric]

I am using a stereo camera like this one, the output of both cameras is a mjpg in /dev/video1 and /dev/video2.

Is it possible to use rtabmap with this kind of setup (without using ROS) ?

[matlabbe]

Without ros, rtabmap supports stereo USB camera, as.long as the camera can stream side by side images. To read from two input sources, a new driver would have to be created, which could be similar to CameraStereoVideo class. However, stereo images should be exactly symchronized, so it is preferred that the camera is able to stream already synchronized images.

Cheers, Mathieu

[patrickelectric]

Ty @matlabbe, I'll be very glad to write a new driver for rtabmap ! I believe that scenario is pretty common, and this new drive can be util. My best regards

[matlabbe]

The CameraStereoVideo class with two videos as input can be very close to what you want to achieve. For example, this code:

capture_.open(path_.c_str());
capture2_.open(path2_.c_str());

could be replaced by:

capture_.open(usbDevice1);
capture2_.open(usbDevice2);

However, why the original code doesn't support 2 usb devices but just 2 videos is that there is no certainty that cv::VideoCapture called on two devices will give the frames at the same time. Timing is very important for stereo. Look if your stereo camera has already a driver that can fetch both images at the same time, then if yes, you may create another CameraStereo[MyDriverName] class based on this driver (like CameraStereoZed for ZED camera or CameraStereoFlyCapture2 for Point grey cameras).

If the camera is a standard UVC camera, it is already compatible with rtabmap (through OpenCV cv::VideoCapture).

cheers, Mathieu

[paulsammut]

As a suggestion, I have used the tara's from E-Con systems and for 250 bucks they are excellent. Baseline is a little small at 6cm, but for indoor use, range from 0.3cm to 3m the data they return is great. Better than ZED at that range.

They have a decent ROS driver and work well with rtabmap. Very very very worth the little amount of money they cost when compared to any other decent stereo rig.

[jm677zz]

Tara has been very widely in outdoor applications where sunlight is there. E-con Systems provides a C++ SDK for Windows and Linux and includes some standard analysis examples using OpenCV such as height estimation, face detection, and point cloud generation.