Hogwarts, Dewarped.
2002: fisheye footage from the set of Harry Potter and the Chamber of Secrets, dewarped frame by frame with an in-house algorithm for the film’s DVD, through iPIX.
Dewarping a Hogwarts fisheye
Fisheye footage from a film set, turned into a view anyone could watch.
In 2002 Doo Interactive received, through iPIX (Internet Pictures Corporation), fisheye footage shot on the set of Harry Potter and the Chamber of Secrets for the film’s DVD. The task: convert every frame from a raw fisheye circle into a correct, navigable view, using a dewarping algorithm written in-house.
One shot from the Chamber set. Left: the frames as filmed. Right: the same frames dewarped, panning as a viewer would. Rebuilt in 2026 from the original 2002 files.
frames in a single shot
filmed on set, take 7
dewarped in-house
Potter 2, the DVD
The first frame of the shot carries the slate: “Potter 2 – The DVD”, Warner, slate C4-5, take 7, 11 June 2002. The set is the Chamber: the stone walkway, the serpent heads, the opening in the ceiling.
Running the lens backwards
A fisheye lens compresses half a sphere of space into a circle. Dewarping inverts that projection for every output pixel. In 2002 this ran entirely on the processor, without GPUs or off-the-shelf libraries.
The iPIX partnership
iPIX grew out of a NASA-funded programme to guide robots with fisheye cameras. Doo Interactive worked with it from 1998: Biron and Lascaux, the nuclear sites, Accor. iPIX went bankrupt in 2006; the image processing know-how built on its projects carried on.
Harry Potter and the Chamber of Secrets © Warner Bros. Shown as a record of the work.