Camera calibration file about redtail HOT 1 CLOSED

Most likely this happens because OpenCV FileStorage writes YAML file that is not compatible with most other YAML readers (e.g. Python etc). The problem is in the first line of the output file, that's why, for example, in our Python script we have to remove it.
However, there is a bigger issue: the calibration parameters are not actually used to undistort an image. The reason is gscam uses camera_info_manager from image_common which reads the calibration file and publishes it as a topic but does not actually perform undistortion. On the other hand, performing undistortion in our code (i.e. caffe_ros) node is too late as the node is subscribed to the output of gscam which means the image went through GStreamer pipeline like resizing etc so undistorting it does not make sense anymore/too late.
In our case, this was not a problem as our Iris drone used Microsoft HD5000 camera with 66 degrees of diagonal FOV so there was never any noticeable distortions.

For wide angle cameras we would certainly recommend undistorting the image before feeding into caffe_ros. In another scenario where we use ZED camera, the ZED ROS node conveniently provides a topic with rectified image (example).

Hope this clarifies things a little...

from redtail.