autonomousvision
code for stitching the two fisheyes to make an equirectangular image
Thanks for the great dataset!
I know it wasn't this dataset's intention, but I was wondering if it is possible to make a 360 image (equirectangular image) from the two 180 fisheye cameras. If someone did it or if you know any good method to go about this, it would be helpful.
I tried to go do it naively and made a dual-fisheye image and tried to stitch it on the Theta camera's conversion app, but it didn't work out. I haven't really done fisheye conversions, but my guess is that the two fisheyes are too far apart to create a perfect equirectangular image. Then again, it seems like the 180 fisheye seems to be capturing more than 180 degrees (more like 190 degrees?)
Any help would be appreciated.
Hi, I've tried tackling this problem myself to limited success.
Going by this answer on Stack Overflow, newer versions of FFmpeg have a v360 filter to convert fisheye/dual fisheye images to equirectangular, which can take either a single image or a video. So I concatenated a fisheye pair to get a dual fisheye image, tested some FOV parameters of the filter (trial and error, really) to get this:
Obviously, the sharp border isn't great, which led me down another rabbit hole about blending and saw this open enhancement ticket. Trying a couple of the suggestions in there from Michael Koch (for windows batch, but the arguments for bash are similar enough) got me this:
Still isn't ideal, but slightly better than before. I'm sure someone more familiar with blending/stitching can do a much better job than I did. Michael Koch also links his book with some more examples on the filter: http://www.astro-electronic.de/FFmpeg_Book.pdf.
@helmifraser Thanks for sharing with me your workflow. Wow, that looks so much better than mine.
I tried using Hugin to stitch, but can't get reliable control points since it doesn't overlap as much.
I thought it would be easy, but I too fell in the rabbit hole :(
@helmifraser hi helmifraser and @haruishi43 haruishi43 , do you guys know how to convert the fisheye image to an equirectangular image in a batch?
