How to setup Qt and openCV on Wi
How to setup Qt and openCV on Windows
[[Category:HowTo]]
== Introduction ==
This article shows how to install Qt, build OpenCV, and run a basic OpenCV example. This article assumes Windows 10 has just been installed.
This procedure requires close to 10GB of disk space:
Qt: 5.06GB
opencv: 522MB
opencv-Build: 3.95GB
downloads:152MB
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 10, Qt 5.9, OpenCV 3.2.0 ==
=== 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-Qt5.9-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 taskbar 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 ===
Todo
=== 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/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.
==== Add minGW to the windows PATH variable====
Open the control panel,
System and Security,
System,
Advanced system settings,
Environment Variables,
System Variables,
Variable Name: Path
Variable value: ;D:\Qt\Tools\mingw530_32\bin
==== 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
Check the box [X]WITH_OPENGL
Then click configure again
Set QT_MAKE_EXECUTABLE to D:\Qt\5.9\mingw53_32\bin\qmake.exe
Set Qt5Concurrent_DIR to D:\Qt\5.9\mingw53_32\lib\cmake\Qt5Concurrent
Set Qt5Core_DIR to D:\Qt\5.9\mingw53_32\lib\cmake\Qt5Core
Set Qt5Gui_DIR to D:\Qt\5.9\mingw53_32\lib\cmake\Qt5Gui
Set Qt5Test_DIR to D:\Qt\5.9\mingw53_32\lib\cmake\Qt5Test
Set Qt5Widgets_DIR to D:\Qt\5.9\mingw53_32\lib\cmake\Qt5Widgets
Set Qt5OpenGL_DIR to D:\Qt\5.9\mingw53_32\lib\cmake\Qt5OpenGL
Set CMAKE_BUILD_TYPE to Release or RelWithDebInfo
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. On a core i7-3770@3.4GHz with 8GB ram, the compile takes about 6 minutes.
d:
cd d:\
cd opencv-build
mingw32-make -j 8
mingw32-make install
If you have the following error : ... windres.exe: unknown option -- W ...
try this : in cmake uncheck ENABLE_PRECOMPILED_HEADERS
If, in the file opencv/sources/modules/videoio/src/cap_dshow.cpp, you have the following error : 'sprintf_instead_use_StringCbPrintfA_or_StringCchPrintfA' was not declared in this scope ...
try this :put the following line: #define NO_DSHOW_STRSAFE, before the line : #include "DShow.h"
If you have the error: ‘nullptr’ was not declared in this scope..
try this: in cmake check the box ENABLE_CXX11
If, in the file modules\videoio\src\cap_msmf.cpp you have the error: using invalid field '{anonymous}::ComPtr<T>::p'..
try this: in cmake unchecking WITH_MSMF
==== Add OpenCV compiled libraries to the windows PATH variable====
Open the control panel,
System and Security,
System,
Advanced system settings,
Environment Variables,
System Variables,
Variable Name: Path
Variable value: ;D:\opencv-build\install\x86\mingw\bin
=== Compile and run the example ===
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.
modify the .pro file like this:
<syntaxhighlight lang="cpp">
#-------------------------------------------------
#
# Project created by QtCreator 2017-03-05T12:30:06
#
#-------------------------------------------------
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = opencvtest
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\include
LIBS += D:\opencv-build\bin\libopencv_core320.dll
LIBS += D:\opencv-build\bin\libopencv_highgui320.dll
LIBS += D:\opencv-build\bin\libopencv_imgcodecs320.dll
LIBS += D:\opencv-build\bin\libopencv_imgproc320.dll
LIBS += D:\opencv-build\bin\libopencv_features2d320.dll
LIBS += D:\opencv-build\bin\libopencv_calib3d320.dll
# more correct variant, how set includepath and libs for mingw
# add system variable: OPENCV_SDK_DIR=D:/opencv/build
# read http://doc.qt.io/qt-5/qmake-variable-reference.html#libs
#INCLUDEPATH += $$(OPENCV_SDK_DIR)/include
#LIBS += -L$$(OPENCV_SDK_DIR)/x86/mingw/lib \
# -lopencv_core320 \
# -lopencv_highgui320 \
# -lopencv_imgcodecs320 \
# -lopencv_imgproc320 \
# -lopencv_features2d320 \
# -lopencv_calib3d320
</syntaxhighlight>
and modify mainwindow.cpp like this:
<syntaxhighlight lang="cpp">
#include "mainwindow.h"
#include "ui_mainwindow.h"
#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;
}
</syntaxhighlight>
Place an image with the name "1.img" in the root of F:\, then run the example. Now 2 windows should pop up. One with the image, and one with an empty window.
