[MatthiasWandel]

Back around 2006 I used "panorama tools" to do the same sort of thing. It had this cool feature of being able to work out lens calibration if it had two photos from the same viewpoint but different angles. It did however require careful tagging of reference points on each image.

[mnw21cam]

The logical successor to panorama tools is hugin these days, and yes it is able to perform these transformations very easily. The control point generation can be done automatically now, although I admit it might struggle a little with fisheye images.