OpenCV integration with Qt creator

[mind_freak]

hi
I am new to OpenCV and i want to use OpenCV libraries to my application but i don't know the proper way to configure it with Qt creator IDE.

i have gone through many post regarding my problem but it seems to be a bit higher level and i am searching for basic configuration with Qt creator.

Thanks...

[stampede]

As for any other 3rd party library, you have to add include path to your .pro file:

// project.pro
INCLUDEPATH += C:/OpenCV/cv/include \
		C:/OpenCV/cvaux/include \
		// ... other components if needed

// project.pro
INCLUDEPATH += C:/OpenCV/cv/include \
		C:/OpenCV/cvaux/include \
		// ... other components if needed

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and library path for linker (this is for dynamic linking):

// project.pro
LIBS += -LC:/OpenCV/bin   //!< path to .dll files
LIBS += -lcv100	-lcvaux100 // here cv100.dll and cvaux.dll are linked, add other libs if needed

// project.pro
LIBS += -LC:/OpenCV/bin   //!< path to .dll files
LIBS += -lcv100	-lcvaux100 // here cv100.dll and cvaux.dll are linked, add other libs if needed

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Last thing to do is to configure the QtCreator indexer, to be able to use code completion with symbols from OpenCV library.
I don't know if there is a way to "click" it, I've just updated the "project.includes" file (its a txt file, so you can just paste the include paths there):

// project.includes
//...
C:\OpenCV\cv\include
C:\OpenCV\cxcore\include
// other path for indexer
// ...

// project.includes
//...
C:\OpenCV\cv\include
C:\OpenCV\cxcore\include
// other path for indexer
// ...

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Now OpenCV is ready to use with your project.
All above was for OpenCV 1.0 and Windows platform, but the principle is the same for any OS and library version ( new OpenCV is separated into modules, so there will be more to include / link ).

[mind_freak]

#-------------------------------------------------
#
# Project created by QtCreator 2011-02-18T14:52:13
#
#-------------------------------------------------
 
QT       += core gui
 
TARGET = samplecv
TEMPLATE = app
 
 
SOURCES += main.cpp\
        mainwindow.cpp
 
HEADERS  += mainwindow.h
 
FORMS    += mainwindow.ui
 
CONFIG += mobility
MOBILITY = 
INCLUDEPATH += C:/OpenCV2.2/include/opencv \
C:/OpenCV2.2/include/opencv2
LIBS+= C:/OpenCV2.2/lib/*.lib
symbian {
    TARGET.UID3 = 0xe10417cf
    # TARGET.CAPABILITY += 
    TARGET.EPOCSTACKSIZE = 0x14000
    TARGET.EPOCHEAPSIZE = 0x020000 0x800000
}

#-------------------------------------------------
#
# Project created by QtCreator 2011-02-18T14:52:13
#
#-------------------------------------------------

QT       += core gui

TARGET = samplecv
TEMPLATE = app


SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

CONFIG += mobility
MOBILITY = 
INCLUDEPATH += C:/OpenCV2.2/include/opencv \
C:/OpenCV2.2/include/opencv2
LIBS+= C:/OpenCV2.2/lib/*.lib
symbian {
    TARGET.UID3 = 0xe10417cf
    # TARGET.CAPABILITY += 
    TARGET.EPOCSTACKSIZE = 0x14000
    TARGET.EPOCHEAPSIZE = 0x020000 0x800000
}

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Am i true with this kind of declaration....i haven't been that much familiar with opencv....

if possible can you help with an Qt example together with OpenCV...

Thanks

[stampede]

Ok, you have includes and libraries (I assume that paths are correct), so what exactly is the problem ? You cannot build the project ?

[mind_freak]

Error i am getting is shown below:

Running build steps for project samplecv...
Configuration unchanged, skipping qmake step.
Starting: "C:\QtSDK\mingw\bin\mingw32-make.exe" -w
mingw32-make: Entering directory `C:/Users/mind_freak/samplecv-build-desktop'
C:/QtSDK/mingw/bin/mingw32-make -f Makefile.Debug
mingw32-make[1]: Entering directory `C:/Users/mind_freak/samplecv-build-desktop'
g++ -c -g -frtti -fexceptions -mthreads -Wall -DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_GUI_LIB -DQT_CORE_LIB -DQT_HAVE_MMX -DQT_HAVE_3DNOW -DQT_HAVE_SSE -DQT_HAVE_MMXEXT -DQT_HAVE_SSE2 -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN -I"..\..\..\QtSDK\Desktop\Qt\4.7.1\mingw\include\Qt Core" -I"..\..\..\QtSDK\Desktop\Qt\4.7.1\mingw\include\Qt Gui" -I"..\..\..\QtSDK\Desktop\Qt\4.7.1\mingw\include " -I"..\..\..\OpenCV2.2\include\opencv" -I"..\..\..\OpenCV2.2\include\opencv2" -I"..\..\..\QtSDK\Desktop\Qt\4.7.1\mingw\include\Ac tiveQt" -I"debug" -I"." -I"..\samplecv" -I"." -I"..\..\..\QtSDK\Desktop\Qt\4.7.1\mingw\mkspecs\wi n32-g++" -o debug\main.o ..\samplecv\main.cpp
mingw32-make[1]: Leaving directory `C:/Users/mind_freak/samplecv-build-desktop'
mingw32-make: Leaving directory `C:/Users/mind_freak/samplecv-build-desktop'
In file included from ..\samplecv\/mainwindow.h:5,
from ..\samplecv\main.cpp:2:
..\..\..\OpenCV2.2\include\opencv/cv.h:63:33: error: opencv2/core/core_c.h: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:64:33: error: opencv2/core/core.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:65:39: error: opencv2/imgproc/imgproc_c.h: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:66:39: error: opencv2/imgproc/imgproc.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:67:38: error: opencv2/video/tracking.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:68:45: error: opencv2/features2d/features2d.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:69:35: error: opencv2/flann/flann.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:70:39: error: opencv2/calib3d/calib3d.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:71:43: error: opencv2/objdetect/objdetect.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:72:37: error: opencv2/legacy/compat.hpp: No such file or directory
..\..\..\OpenCV2.2\include\opencv/cv.h:79:37: error: opencv2/core/internal.hpp: No such file or directory
In file included from ..\samplecv\/mainwindow.h:6,
from ..\samplecv\main.cpp:2:
..\..\..\OpenCV2.2\include\opencv/highgui.h:47:39: error: opencv2/highgui/highgui_c.h: No such file or directory
..\..\..\OpenCV2.2\include\opencv/highgui.h:48:39: error: opencv2/highgui/highgui.hpp: No such file or directory
mingw32-make[1]: *** [debug/main.o] Error 1
mingw32-make: *** [debug] Error 2
The process "C:\QtSDK\mingw\bin\mingw32-make.exe" exited with code 2.
Error while building project samplecv (target: Desktop)
When executing build step 'Make'

[stampede]

..\..\..\OpenCV2.2\include\opencv/cv.h:63:33: error: opencv2/core/core_c.h: No such file or directory

You need to add path to "opencv2/<module>" directory to your .pro file, for each module listed in above error. Modules should be in "C:/OpenCV2.2/modules".
For example, "core" module is in:

C:\OpenCV2.2\modules\core

, it has "include" subdir, which contains the path referenced in cv.h above. So for this module, entry in .pro file would be:

INCLUDEPATH += C:/OpenCV2.2/modules/core/include

Look into your OpenCV 2.2 installation directory and add all missing modules path to your .pro file.

[mind_freak]

hey when i download opencv 2.2 from sourcefroge i have two option
1)opencv.zip
2)opencv.exe for vs2010

which one to download so that i can use it with Qt creator.....

[mind_freak]

i don't know which to select so that i can configure it properly with Qt Creator 2.0.95,

[stampede]

Which compiler are you using ? I think there are prebuilt packages available for Visual C++ compilers, so this ".exe for vs" is probably this package.
I'm using g++, so I've had to build OpenCV myself ( not really difficult, just download CMake and click few times, I think there is even a step-by-step tutorial somewhere ).
So it depends on the compiler, if you use g++ download something like "OpenCV-2.2.0-win.zip".

[mind_freak]

m using Nokia Qt sdk ,so which compiler does it consist of ??

[squidge]

MinGW/GCC, unless you specified otherwise.

[Orlando10]

I need to know how to fix the following problem that I get when I try to configure the CMake. please I need some help.