View source for How to setup Qt and openCV on Windows

How to setup Qt and openCV on Windows

{{Cleanup | reason=Incomplete and not functional.}}
[[Category:HowTo]]

== Introduction ==
 WARNING: The below procedures are incomplete, and not functional.
This article shows how to install both Qt and openCV, and build a basic OpenCV example. This article assumes Windows 7 has just been installed.

This article uses information from the following pages:
http://docs.opencv.org/2.4/doc/tutorials/introduction/windows_install/windows_install.html?highlight=installation
http://www.laganiere.name/opencvCookbook/chap1s1_2.shtml

== Windows, source of openCV, old version ==
This section is a direct copy of [http://www.laganiere.name/opencvCookbook/chap1s1_2.shtml this] guide. Only minor changes are done to make it work with a newer version of Qt.
=== Qt ===
==== Installation ====
Download the Qt installer from [https://www.qt.io/download-open-source/ www.qt.io], then choose "Download now". This will then download qt-unified-windows-x86-2.0.5-online.exe. Execute the program, then choose the following settings:
 Welcome to the Qt online installer: next
 Qt Account - your unified login to everything Qt: skip
 Setup-Qt: next
 installation folder: D:\Qt
 select components: Qt-Qt5.8-MingGW 5.3.0 32 bit
 select components: Qt-Tools-MinGW 5.3.0
 License Agreement: agree and next
 start menu shortcuts: next
 ready to install: install
==== Testing ====
Run D:\Qt\Tools\QtCreator\bin\qtcreator.exe
  File-New file or project-Qt Widgets Application-choose
  enter a name and a location: next
  select all kits: next
  Class information: MainWindow (defaults): Next
  Project management: Finish
Now a new project is made. Start debugging by choosing
  Debug-Start Debugging-Start debugging (F5)
Now the Qt tab in the windows task bar should turn into a progress bar. After some time a new empty window should pop up. Stop debugging either by pressing the red cross in the top right of this new window, or choose
  Debug-Stop debugging  
==== Adjust Qt ====
When you need to add, remove or update a component of Qt, this can be done by running D:\Qt\MaintenanceTool.exe:
 maintain Qt: Qt Account: Skip
 Setup Qt: Add or remove components: Next
 Select components: 
 next :update 

=== Tortoisegit ===

=== Cmake ===
Download cmake from [https://cmake.org/download/ cmake.org]. In this guide, [https://cmake.org/files/v3.7/cmake-3.7.2-win64-x64.msi 3.7.2] is used. Start cmake-3.7.2-win64-x64.msi, then choose the following settinge:
  Welcome to the CMake etup Wizzard: next
  End-User License Agreement: [X] Accept and next
  Install options: [X] Add CMake to the system PATH for all users, next
  Destination folder: C:\Program Files\CMake (default), next
  Ready to install CMake, Install

=== OpenCV ===
==== Getting OpenCV ====
Download openCV from [https://sourceforge.net/projects/opencvlibrary/ sourceforge]. In this guide, version [https://sourceforge.net/projects/opencvlibrary/files/opencv-win/2.3.1/ 2.3.1] is used. Start OpenCV-2.3.1-win-superpack.exe and let it extract to d:\ Now the folder d:\opencv is created.
==== Compiling OpenCV ====
Start C:\Program Files\CMake\bin\cmake-gui.exe then choose the following settings:
  Where is the source code: D:/openv
  where to build the binaries: D:\opencv-build
Then click Configure and choose the following settings:
  Specify the generator for this project: MinGW Makefiles
  Specify native compilers, next
  Compilers C: D:/Qt/Tools/mingw530_32/bin/gcc.exe
  Compilers C++: D:/Qt/Tools/mingw530_32/bin/g++.exe
  Finish
Now the error "Error in configuration process, project files may be invalid" comes up
  Click the checkbox [Advanced], then click the red line
  CMAKE_MAKE_PROGRAM and browse to D:/Qt/Tools/mingw530_32/bin/mingw32-make.exe
Then click Configure. Now the error "the system can't start because libwinpthread-1.dll is missing from your computer. Try reinstalling the program to fix this problem."


The C compiler "D:/Qt/Tools/mingw530_32/bin/gcc.exe" is not able to compile a simple test program. It fails with the following output:
CMakeFiles\cmTC_9c5ad.dir\build.make:64: recipe for target
  'CMakeFiles/cmTC_9c5ad.dir/testCCompiler.c.obj' failed
  
Add to the system path solves above problems.

  Change CMAKE_BUILD_TYPE from Debug to Release
  Check the box [X]WITH_QT
  Check the box [X]WITH_QT_OPENGL
Then click configure again
Then click generate  

Next open cmd, and type the following commands:
  cd d:\
  cd opencv-build
  ming32-make -j 8
  ming32-make install

==== Installing OpenCV ====
==== Configuring OpenCV ====
=== Building and running an example ===
add D:\opencv-build\install\bin to path

modify the .pro file like this:
#-------------------------------------------------
#
# Project created by QtCreator 2017-03-05T12:30:06
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = untitled
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0


SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

INCLUDEPATH += D:\opencv-build\install\include
LIBS += -LD:\opencv-build\install\lib \
    -lopencv_core231.dll \
    -lopencv_highgui231.dll \
    -lopencv_imgproc231.dll \
    -lopencv_features2d231.dll \
    -lopencv_calib3d231.dll



== Windows, Binary Qt, openCV from source ==
 Todo: Qt instructions the same as above, 
 Todo: Cmake instructions the same as above
 
=== OpenCV ===
==== Getting OpenCV ====
Download openCV from [https://sourceforge.net/projects/opencvlibrary/ sourceforge]. In this guide, version [https://sourceforge.net/projects/opencvlibrary/files/opencv-win/3.2.0/ 3.2.0] is used. Start opencv-3.2.0-vc14.exe and let it extract to d:\ Now the folder d:\opencv is created.
==== Compiling OpenCV ====
Start C:\Program Files\CMake\bin\cmake-gui.exe then choose the following settings:
  Where is the source code: D:/opencv/sources
  where to build the binaries: D:\opencv-build
Then click Configure, let cmake create the build directory, and choose the following settings:
  Specify the generator for this project: MinGW Makefiles
  Specify native compilers, next
  Compilers C: D:/Qt/Tools/mingw530_32/bin/gcc.exe
  Compilers C++: D:/Qt/Tools/mingw530_32/bin/g++.exe
  Finish

  Check the box [X]WITH_QT
Then click configure again
  Set CMAKE_BUILD_TYPE to Release or RelWithDebInfo
  Set Qt5Core_DIR to D:\Qt\5.8\mingw53_32\lib\cmake\Qt5Core
  Set Qt5Concurrent_DIR D:\Qt\5.8\mingw53_32\lib\cmake\Qt5Concurrent
  Set Qt5Core_DIR D:\Qt\5.8\mingw53_32\lib\cmake\Qt5Core
  Set Qt5Gui_DIR D:\Qt\5.8\mingw53_32\lib\cmake\Qt5Gui
  Set Qt5Test_DIR D:\Qt\5.8\mingw53_32\lib\cmake\Qt5Test
  Set Qt5Widgets_DIR D:\Qt\5.8\mingw53_32\lib\cmake\Qt5Widgets

Then click configure again
Then click generate  

Next open cmd, and type the following commands. To speed up the compile, the -j flag can be used to run multiple compile jobs simultaneously. On an 8 core CPU, you can set it to 8 or higher, so all cores are used.
  d:
  cd d:\
  cd opencv-build  
  mingw32-make -j 8
  mingw32-make install  
  
  
  
  
  
  
  
  
  
  
  
== Windows, precompiled binaries, new versions ==


=== Install OpenCV ===
Download the newest version from [https://sourceforge.net/projects/opencvlibrary/files/opencv-win/ sourceforge ]. At the time of this writing, [https://sourceforge.net/projects/opencvlibrary/files/opencv-win/3.2.0/ opencv-3.2.0-vc14.exe] (118MB) is the latest version. Execute the program, then enter a location with at least 460MB free. This how to assumes OpenCV to be extracted to "d:\", so the folder d:\opencv exists.

=== Install Qt ===
Download the Qt installer from [https://www.qt.io/download-open-source/ www.qt.io], then choose "Download now" This will then download qt-unified-windows-x86-2.0.5-online.exe Execute the program, then choose the following settings:
 welcome next
 qt account skip
 setup-Qt next
 installation folder: D:\Qt
 select components: next (accept defaults)
 License Agreement: agree and next
 start menu shortcuts: next
 ready to install: install

=== Adjust Qt ===
Run D:\Qt\MaintenanceTool.exe then use the following options:
 maintain Qt: Qt Account: Skip
 Setup Qt: Add or remove components: Next
 Select components: Qt-Qt5.8-MinGW 5.3.0 32 bit
 Select components: tools-MinGW 5.3.0 32 bit: next :update

=== Configure Qt and OpenCV ===

=== Compile and run the example ===
modify the .pro file like this:
#-------------------------------------------------
#
# Project created by QtCreator 2017-03-05T12:30:06
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = untitled
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0


SOURCES += main.cpp\
        mainwindow.cpp

HEADERS  += mainwindow.h

FORMS    += mainwindow.ui

INCLUDEPATH += D:\opencv-build\install\include
LIBS += -LD:\opencv-build\install\x86\mingw\lib \
    -lopencv_core320.dll \
    -lopencv_highgui320.dll \
    -lopencv_imgcodecs320.dll \
    -lopencv_imgproc320.dll \
    -lopencv_features2d320.dll \
    -lopencv_calib3d320.dll

and modify mainwindow.cpp like this:
#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
/*
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>*/

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // read an image
    cv::Mat image = cv::imread("f://1.jpg" , 1 );
    // create image window named "My Image"
    cv::namedWindow("My Image");
    // show the image on window
    cv::imshow("My Image", image);
}

MainWindow::~MainWindow()
{
    delete ui;
}
	
	
NOTE: after changing the PATH variable, restart QtCreator to load the new value	

When this example is run, 2 windows pop up. One with the image, and one with an empty window.