# Alternative to findHomography ?

Hi there, I'm here with an annoying problem. I have 2 images I want to register. To do that I own 2 datasets of points in which I can have some outliers. The best function I could use for that would be findHomography, but I can't. Indeed I'm using a GTK3 project while calib3d is using GTK2. As a consequence I have :

Gtk-ERROR **: GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported


So, as it seems I cannot use findHomography, are there other functions (not in opencv3) to do what I want ?

Or, maybe someone has an idea to use findHomography by avoiding the conflict (for sure, findHomography is exactly what I want ... So I'm feeling frustrated)

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findHomography, or even opencv's calib3d module are absolutely unrelated to gtk, only the highgui module(imshow) might depend on it.

several things to try:

• if you're using opencv3, do not link against highgui (and modify the code, so it'S not using imshow, but your own gtk3 window

• you could try to rebuild opencv without gtk support (cmake -DWITH_GTK=OFF)

( 2015-05-17 04:10:44 -0500 )edit

I'm using opencv2 and do not include highgui. I took the repository version. I'm sure what i'm saying because every time I add the flag : lopencv_calib3d to compil the project, I have the GTK error ... Maybe because of the drawChessboardCorners function ? This function is available in the module but not used in my project.

May I disable the gtk support from repository version ? With a compiler flag ?

( 2015-05-17 04:52:50 -0500 )edit

ok, i might be wrong about it, but drawChessboardCorners is only manipulating an image.

it might rather be due to inter-modules dependancies, also, image loading is in highgui (in 2.4, but not in 3.0)

"I took the repository version" - means what ? ppa ? git src ? (and no, if you only got binaries, you can't change any behaviour of that)

btw, which opencv version is it ?

( 2015-05-17 05:15:47 -0500 )edit

Sorry I was not clear enough. I'm on Debian testing. I took the version on the debian repository : https://packages.debian.org/testing/l... (opencv 2.4.9). I don't use highgui at all. Indeed, I load images without opencv.

( 2015-05-17 05:22:39 -0500 )edit

ok. would you be able to locate the gtk dependancy ? what exactly do you link ? problem might be related to inter-module dependancies

( 2015-05-17 06:13:48 -0500 )edit

ok. would you be able to locate the gtk dependancy ?

No I can't. I just know that when I add lopencv_calib3d in the compiler flag I have the problem.

I already use -lopencv_core -lopencv_imgproc with no problem. These are the only module I use.

#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>


Thanks for trying to help

( 2015-05-17 07:41:59 -0500 )edit

Ok. After doing ldd on the application, I did see that I have a link on highgui when I use "calib3d" ..... That's un bug ? I don't want to use it !!

( 2015-05-18 02:23:51 -0500 )edit
1

yea, seen your issue. i'd say bug, too. still clueless, why the dependancy on highgui exists at all.

( 2015-05-18 02:31:58 -0500 )edit

Ok thanks. Do you have any idea to avoid this problem ?

I tried to compil OpenCV but apparently as I'm on 64bits it's not that easy : I get errors during compilation even if I have dependencies installed ....

( 2015-05-18 04:14:34 -0500 )edit

Ok, I have found a workaround by removing repository version and compiling the 2.4.10.

( 2015-05-19 04:14:22 -0500 )edit