HDR Video

Since the release of Photoshop CS2's new "Merge to HDR" feature, there has been a lot of buzz about HDR photography. So, naturally, I've gotten curious and have been tinkering with HDRShop, Photoshop CS2's HDR, and PhotoMatix, all of which do the job of merging and tonemapping multiple exposures to extend dynamic range. Playing with HDR photography got me thinking about how great it would be to apply this technique to digital video, a medium that also suffers from reduced dynamic range. Why not shoot your N frames per second of video at N/(2 or 3) fps bracketing each exposure, then merge and tonemap the bracketed shots? Or, shoot at 2 or 3 times the frame rate bracketing each shot? Voilà! HDR video! Such an obvious idea that someone's already done it, right? Right. So I went looking for who has. My search led to one group at Microsoft Research who've written this article, and published this interesting proof of concept video. I also found this article describing a prototype split aperture camera designed for acquiring sequences of bracketed images. This seems like a better approach than trying to vary the shutter speed of an OTS camera frame-by-frame as described in this paper by Simon Hoffmann. Hoffmann put together such a system using a JAI CV-S3300 that suffered such slow control over camera shutter speed that it output a poor one frame per second HDR video stream! Not exactly a prototype I'm dying to reproduce!

Tags: hdr video | hdr photography | hdri