lsd_slam | LSD-SLAM | Robotics library

I have cloned lsd_slam from github this link
in section 2.2 of the README file the auther wrote that ros required, so I followed the instruction as it mentioned there :

We do not use catkin, however fortunately old-fashioned CMake-builds
are still possible with ROS indigo. For this you need to create a rosbuild workspace (if you don't have one yet), using:

sudo apt-get install python-rosinstall
mkdir ~/rosbuild_ws
cd ~/rosbuild_ws
rosws init . /opt/ros/indigo
mkdir package_dir
rosws set ~/rosbuild_ws/package_dir -t .
echo "source ~/rosbuild_ws/setup.bash" >> ~/.bashrc
bash
cd package_dir

but when I reach at the stage of initializing, this error is what I face:

kave@kave-ThinkPad-X201:~/dev/rosbuild_ws$ rosws init . /opt/ros/indigo
Using ROS_ROOT: /opt/ros/indigo ERROR in config: Is not a local file, nor a valid URL [/opt/ros/indigo] : unknown url type: /opt/ros/indigo

I dont know how to solve the problem.

For an augmented reality application I am using some slam algorithm to predict the current orientation of my mobile phone.

The algorithm (LSD-Slam) supplies the current pose in form of a SE3 lie group (using Sophus::Sim3f). If I got this right, this type contains a matrix which can be interpreted as the Viewmatrix of a Camera. After initialisation, e.g. the matrix looks like this: