Using Polyora with SiftGPU

Polyora is more accurate and more reliable, but slower with SiftGPU.

SiftGPU is not included in polyora because its license is incompatible with GPL.

1. Download SiftGPU from http://www.cs.unc.edu/~ccwu/siftgpu/
2. Decompress and compile the archive in the polyora source directory
3. Edit the file polyora/kpttracker.h, and replace:

   //#define WITH_SIFTGPU
   #define WITH_YAPE
   

   by

   #define WITH_SIFTGPU
   //#define WITH_YAPE
   

4. Run cmake to configure polyora. In the output, make sure cmake says: SiftGPU is ON.
5. Compile polyora
6. Re-create training data (see Basic usage instructions)