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Detecting AR Markers pose with a fisheye lense

asked 2015-01-18 20:19:09 -0500

Mehdi. gravatar image

updated 2015-01-18 20:30:45 -0500

Is there any general library or ROS package that is compatible with fisheye like distorted images? Until now I was undistorting my images and using the ar_track_alvar package but this sacrifices the wide field of view. And what intrinsic calibration information do such programs get? (I think OpenCV 2.x.x only supports pinhole models). An alternative to estimate a monocular fisheye camera pose would also be useful.

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Did you find any information about this topic? I'm also thinking about detecting markers in fisheye images. But I'm not sure if alvar can handle the distortion. Should I risk buying a fisheye camera and not being able to process the images?

Falko gravatar image Falko  ( 2015-10-30 05:06:19 -0500 )edit

The topic is old, but you undistort the image with image_proc after calibrating the camera.

machinekoder gravatar image machinekoder  ( 2019-06-26 10:45:15 -0500 )edit

@machinekoder the whole point was about using the full field of view of the camera to cover more space. Undistorting the image will crop a lot of that field out view out. See my old answer.

Mehdi. gravatar image Mehdi.  ( 2019-06-27 04:51:07 -0500 )edit

But keep in mind undistorting should not sacrifice FOV. It just undistorts the image of the fisheye lens, which itself already loses information compared to a less distorted lens (more details on the same image sensor area). So yes, the fisheye lens can indeed improve FOV compared to a standard lens, with the cost of image quality.

machinekoder gravatar image machinekoder  ( 2019-06-28 04:56:48 -0500 )edit

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answered 2015-10-30 05:24:10 -0500

Mehdi. gravatar image

I don't think it can handle distorted images as it probably looks for edges/corners of the makers and expects them to be of form line segments. You could use the undistorted image though but you would lose some field of view.

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Asked: 2015-01-18 20:19:09 -0500

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Last updated: Jan 18 '15