OpenCV + Qt on ARM-based Linaro Linux

[old_ufo]

So, today we`ll install OpenCV + Qt on our ARM-based board.

Cool programmers usually do next thing:
1)Cross compile Qt + OpenCV for ARM-board on their home (work) computer
2)Copy libraries and binaries to the SD-card.
3)Develop project on their home(work) computer, cross-compile it for ARM-board, then copy there and execute.

Why? Because desktops are much more powerful than all this boards -> programms can be compiled very fast. For example, 5 seconds instead 5 minutes. And it is more convinient to work at your usual workplace.

BUT! It can be little bit complicated (or no so little) to cross-compile Qt on ARM-based board. I spent 2 days trying and got nothing except errors like this:

"Basic XLib functionality test failed!
You might need to modify the include and library search paths by editing
QMAKE_INCDIR_X11 and QMAKE_LIBDIR_X11 in ..."

I almost learned first ~10 Google pages about this error, for request "Cross compiling Qt/X11" and similar  - and nothing.
 (If you really could do this - please, write comment about it).

So, I propose another, simpler way.
We`ll install Qt from repository. It means that Qt will be installed in BOARD, not home computer and we have write programm on board too. And compile it on board slowly.
But we have not to cross-compile Qt from source and haven`t to solve some weird problems. And our programm (OK, my one) isn`t so big so it can be compiles even on board in 2-3 minutes. Enough to coffee-break but not lunch :)

1)Connect with board via ssh "ssh -X linaro@192.168.1.4" (your board-IP can be different)

2)Type "sudo apt-get install build-essential qtcreator qt4-dev-tools libqt4-dev"
May be not all phis packages are nessesary, but I don`t mind :)
If all is OK, you can type in comsole "qtcreator" and see this so cute IDE.

3)Type "sudo apt-get install libgtk2.0-dev" - beacuse we want to use OpenCV highgui module (not so high, really - just windows with camera video)

4)Compile and install OpenCV. I don`t want to rewrite good manuals so russian is here and english is here

5)Congratulations :) 

Now you have installed OpenCV, Qt IDE and are ready to write some computer vision app omn your IGEPv2 board.