How can I obtain the real focal distance from the stereo camera calibrator app?

I am trying to obtain the real focal distance of my stereo camera pair, but the stereo camera calibrator app returns F (the real focal length) as a vector comformed by and . At the documentation of the app, it is specified that:

• 
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But it does not specify how can I obtain and . I apreciate your help in advance.

Answer 1

[Abhinav Aravindan]

I understand that you're interested in calculating the focal length in world units (millimeters) from the intrinsic camera parameters “fx” and “fy”. During camera calibration, the focal length is estimated in pixels, independent of the camera dimensions. To compute the focal length in world units, the pixel size on the camera sensor needs to be known, which may be obtained from the manufacturer’s specifications to estimate “sx” and “sy”, where “sx” and “sy” are the number of pixels per world units in the x and y direction respectively.

Similar queries to yours have been answered in the below links:

https://www.mathworks.com/matlabcentral/answers/268806

https://www.mathworks.com/matlabcentral/answers/230668

For further detail, please refer to the documentation links below:

https://www.mathworks.com/help/vision/ug/camera-calibration.html

https://www.mathworks.com/help/vision/ref/stereocameracalibrator-app.html

https://www.mathworks.com/help/vision/ref/cameraparameters.html

[Javier Alvarez Nogales]

I am grateful for your response, thank you too much.