setup for stereo with video

[youssef]

Hello,
First of all sorry about my english, it's far from perfect.
I want to use the rtabmap program to extract a point cloud from a stereo video, in this case stereo video from 2 go pro camera.
I do not need to work in real time.

I have installed the stand alone rtab map program. With it, i have used the files from the stereovision tutorials and i was able to obtain a point cloud.

Now i am completely lost on how to use it with my videos.

I have 2 go pro camera and the stand alone rtab map program.

From what i understand, i need to
1) synchronize the 2 videos ==> done
2) calibrate the cameras ==> is the tool rtabmap calibrate can do it or do i have to use another way (opencv)? In case i extract the calibration data with another tool, how to use it?
3) use rtab map with the video ==> do i have to open the video one by one ? or do i have to mix the video in one file ?

Sorry about all these questions but i am really lost on how to use rtab map properly. The stereovision file from the tutorials worked correctly and it's frustrating to not be able to use my data.

Thanks for your help.

Youssef

[matlabbe]

Hello youssef,

I've recently added a new tutorial about using a side-by-side stereo video for offline mapping (including a camera calibration example). You would only need to record side-by-side GoPro videos like the videos in the tutorial. You need also to clone/update the devel branch for this feature.

I think the tutorial will answer all your questions.

cheers

[youssef]

Hello,
Thank you for your reply. I will check the tutorial.

Best regards,
Youssef

[Willy Le Maitre]

Hi Matthieu,
Like Youssef, I've been trying to process one of my own side-by-side videos. I was successful at the tutorial for processing the database of still images. When I try the side-by-side video tutorial to calibrate the chessboard  I encounter a 'camera failed to initialize' error

[ERROR] (2016-05-18 08:55:45) CameraStereo.cpp:944::rtabmap::CameraStereoVideo::init() Camera: Failed to create a capture object!

I'm trying this on version 0.11.2 , I have openCV 3.1.0

Thanks for your help and this amazing project :)

Willy

[matlabbe]

Hi,

It seems that OpenCV cannot open the video file. On the side-by-side stereo tutorial, there is a note about building OpenCV with x264 support:

The first one will be used for calibration. I think you should have installed OpenCV with h264 codec support (e.g., OpenCV is built with FFMPEG+x264) to read these videos.

cheers

[Teiko]

Hi,

your tutorial helped me a lot.
When I finished my calibration a messagebox tells me that the fx-paramter differs by more than 5 to the previous value. Do I have to repeat calibrating until I get a good fx?
I kept the values and saved the results.
Then I entered the prefix of the tree files into the "Calibration file path" field.

When I now press start I am asked to make a calibration...
What did I do wrong that the previous calibration is not accepted?

Thanks!

[matlabbe]

Make sure to set the path of the calibration yaml in Source panel config.