This commit adds support for OpticalFlow to MinnowBoardMax trying to
leave the OpticalFlow implementation as generic as it already is.
We had to add some format conversion and software crop to the cameras that
do not have this features.
Implementation of the PX4 flow algorithm for ardupilot.
Based on the original PX4 Flow code, it has diverged a lot.
I have kept the license header since it is required.
I have removed all the unused and dead code on current implementation,
modified the code to make it clearer, re-indented it and changed
the way some params are calculated. It has been tested on PC and
on board and showed results that I assumed were OK. No optical flow
Loiter tests have been undertaken since it requires a Sonar which will
be added soon.
Limitations :
Some parts were written in ARM assembly and I rewrote them very naively
to get them to be more easily portable. A simple optimisation would be
to re-introduce assembly code for ARM as a separate asm file with
methods for fixed resolutions that would reduce a lot the amount of
calculation and memory read/writes. Then writing a version in NEON
assembly would even be more optimised and then maybe an Intel version.
Ricardo de Almeida Gonzaga
Lucas De Marchi
Julien BERAUD