Tuesday, November 3, 2015

OpenGL : how to install in Ubuntu 14.04

Check if OpenGL is installed or not:
$glxinfo | grep OpenGL
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce GTX 660/PCIe/SSE2
OpenGL core profile version string: 4.3.0 NVIDIA 352.30
OpenGL core profile shading language version string: 4.30 NVIDIA via Cg compiler
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 4.5.0 NVIDIA 352.30
OpenGL shading language version string: 4.50 NVIDIA
OpenGL context flags: (none)
OpenGL profile mask: (none)
OpenGL extensions:

If you get error:

Install mesa-utils and run the command again.

$sudo apt-get install mesa-utils
$glxinfo | grep OpenGL



When you run the sample code firstWindow.cpp, you may get an error:

$ g++ firstWindow.cpp -lglut
/usr/bin/ld: /tmp/ccT2pQWr.o: undefined reference to symbol 'glClear'
//usr/lib/x86_64-linux-gnu/libGL.so.1: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

solution: add -lGL

$ g++ ./firstWindow.cpp -lGL  -lglut 
/usr/bin/ld: cannot find -lGL
collect2: error: ld returned 1 exit status

I got error. 
Solution: Locate libGL.so and create soft link  /usr/lib/libGL.so

$ locate libGL.so

$ sudo ln -s /usr/lib/libGL.so.1 /usr/lib/libGL.so

Wednesday, August 5, 2015

take backup of your tabs and bookmarks in firefox

I was excited to figure out that its possible to take backup of my tabs, windows and bookmarks, basically my "profile" in firefox! Why? I usually keep many tabs and windows open, all for separate purpose and never close them... who knows when they will be helpful!

This is the link published by mozilla. The steps are quite simple too :)



Tuesday, August 4, 2015

Link for Gazebo installation in Ubuntu 12.04 with ROS Hydro package

I had to search a little bit to figure out how to install Gazebo in Ubuntu 12.04 with ROS Hydro package.( Gazebo is now updated with ROS Indigo, which works in Ubuntu 14.04. )

So here is the link: 

After this in terminal,
$ sudo apt-get install ros-hydro-gazebo-ros
$ rosrun gazebo_ros gazebo


Monday, May 18, 2015

Link to PASCAL VOC 2007 Dataset

Link where PASCAL VOC 2007 Dataset available:
(Thanks to Dr  Jasper Uijlings)

How to download vis Linux terminal:
$ wget -m -np http://vision.cs.utexas.edu/voc/
(Ref: http://stackoverflow.com/questions/8386894/download-an-svn-repository )

Found the official mirror to PASCAL VOC datasets (Thanks to Dr  Jasper Uijlings again):


Wednesday, May 13, 2015

MATLAB parfor tips from various resources

Mount cellphone (Nokia Lumia 520) on Ubuntu 12.04


Save RGB image using RGBD sensor and ROS

$roslaunch openni_launch openni.launch
$roslaunch openni2_launch openni2.launch (Depending on the driver that your sensor uses.)
$rosrun image_view image_view image:=/camera/rgb/image_rect_color

A tiny window pops up showing the scene in view. Right click on it to save the image.