[eng] Due to the need of having one more sensor to
calculate the location of an Autonomous Underwater Vehicle
(AUV), in order to increase the accuracy in estimating its position
and velocity, it has been decided to improve the performance
of the well-known LIBVISO2 visual odometer in underwater
environments colonized by algae or seagrass meadows. Furthermore, increasing its robustness to rotations and scale changes
has also been one of the main objectives of this work. To achieve
these targets, its feature detection and matching blocks have been
modified. First, the detection block has been replaced by one that
is more robust to the complex textures of these environments
and also invariant to rotations and scale changes. Secondly, the
efficiency of the matching block has been improved to reduce the
number of outliers produced by these textures.