PanoProjector can convert a spherical panorama in the usual equirectangular projection to cube faces.
Extract a face:
pano-projector face --face=front sphere.jpg front.jpg
Create a tiled pyramid for use by Pannellum:
pano-projector pyramid sphere.jpg out_dir
Create a tiled pyramid for a single face:
pano-projector pyramid sphere.jpg --face=front out_dir
See pano-projector --help for more information about options.
For a 32000x16000 px source image on Intel Core i7-9750H.
Single face extraction:
| User time (s) | Wall time (s) | Max RSS (MiB) | |
|---|---|---|---|
| Hugin's nona | 67.90 | 13.54 | 1874 |
| PanoProjector | 3.82 | 3.90 | 188 |
Single face, pyramid with 512x512px tiles:
| User time (s) | Wall time (s) | Max RSS (MiB) | |
|---|---|---|---|
| PanoProjector | 4.11 | 4.32 | 189 |
All faces, pyramid with 512x512 px tiles:
| User time (s) | Wall time (s) | Max RSS (MiB) | |
|---|---|---|---|
| Pannellum/nona | 517.19 | 129.24 | 1875 |
| PanoProjector | 21.30 | 21.87 | 1471 |
By default, nona uses multiple threads, so the user time exceeds the wall time by a factor of the average number of cores. PanoProjector is single-threaded. It instead relies on just being fast.
Also, by breaking up the job into separate faces, it is possible to parallelize by running multiple instances of the tool. We plan to generate faces on demand, when the user requests them.
PanoProjector is written in C++ and requires C++20. It uses a CMake build system. It depends on libjpeg and Boost program_options.
When it is compiled for an x86-64 architecture, the default build options require a processor equivalent to Intel Skylake or later.
On Debian or similar:
sudo apt-get install gcc cmake libjpeg-turbo8-dev libboost-program-options-dev
cmake -DCMAKE_BUILD_TYPE=Release .
make
sudo make install