Stereo fisheye odometry

[smileyenot983]

Is there any reason why for pinhole cameras images are undistorted and rectified, whereas for fisheye only keypoints are undistorted?

[WFram]

Rectification is done to transform images to the same image plane and required where there are more than one camera. Points from one fisheye to another can be converted using the relative pose between two lenses, which is done.