cuda::kernel::locate_features is the CUDA kernel that uses the fast
lookup table. Shared below is performance of the kernel using constant
memory vs texture memory. There is neglible to no difference between two
versions. Hence, shifted to texture memory LUT to reduce global constant
memory usage.
Performance using constant memory LUT
-------------------------------------
Time(%)    Time   Calls      Avg       Min       Max  Name
1.48%  101.09us      3  33.696us  32.385us  34.976us  void cuda::kernel::locate_features<float, int=9>
1.34%  91.713us      2  45.856us  45.792us  45.921us  void cuda::kernel::locate_features<double, int=9>
1.02%  69.505us      2  34.752us  34.400us  35.105us  void cuda::kernel::locate_features<unsigned int, int=9>
0.99%  67.456us      2  33.728us  32.768us  34.688us  void cuda::kernel::locate_features<int, int=9>
0.95%  65.186us      2  32.593us  31.201us  33.985us  void cuda::kernel::locate_features<short, int=9>
0.93%  63.874us      2  31.937us  30.817us  33.057us  void cuda::kernel::locate_features<unsigned short, int=9>
Performance using texture LUT
-----------------------------
Time(%)    Time   Calls      Avg       Min       Max  Name
1.45%  99.776us      3  33.258us  32.896us  33.504us  void cuda::kernel::locate_features<float, int=9>
1.33%  91.105us      2  45.552us  44.961us  46.144us  void cuda::kernel::locate_features<double, int=9>
1.02%  70.017us      2  35.008us  34.273us  35.744us  void cuda::kernel::locate_features<unsigned int, int=9>
0.97%  66.689us      2  33.344us  32.065us  34.624us  void cuda::kernel::locate_features<int, int=9>
0.95%  65.249us      2  32.624us  31.585us  33.664us  void cuda::kernel::locate_features<short, int=9>
0.95%  65.025us      2  32.512us  30.945us  34.080us  void cuda::kernel::locate_features<unsigned short, int=9>

cuda::kernel::extract_orb is the CUDA kernel that uses the orb
lookup table. Shared below is performance of the kernel using constant
memory vs texture memory. There is neglible to no difference between two
versions. Hence, shifted to texture memory LUT to reduce global constant
memory usage.
Performance using constant memory LUT
-------------------------------------
Time(%)  Time   Calls      Avg       Min       Max  Name
3.02%  292.26us   24  12.177us  11.360us  14.528us  void cuda::kernel::extract_orb<float>
2.16%  209.00us   16  13.062us  11.616us  16.033us  void cuda::kernel::extract_orb<double>
Performance using texture LUT
-----------------------------
Time(%)    Time   Calls      Avg       Min       Max  Name
2.84%  270.63us     24  11.276us  9.6970us  15.040us  void cuda::kernel::extract_orb<float>
2.20%  209.28us     16  13.080us  10.688us  16.960us  void cuda::kernel::extract_orb<double>