Почему я получаю эту ошибку при использовании opencv на QT windows?

Question

У меня возникла эта проблема, когда я установил OpenCV для использования в QT-создателе. Я набрал базовый c код тестирования "cv :: Mat img = imread (" test.png ");" это не компилируется, поскольку дает мне 4 ошибки, которые я показал на картинке.

------------------------.Pro File--------------------------------------
QT       += core gui
QT       += testlib

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11



# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked 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 it uses 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 += \
    editor.cpp \
    image.cpp \
    linked_list.cpp \
    main.cpp \
    mainwindow.cpp \
    tests.cpp

HEADERS += \
    editor.h \
    image.h \
    linked_list.h \
    mainwindow.h \
    node.h

FORMS += \
    editor.ui \
    mainwindow.ui

INCLUDEPATH += \
    D:/boost

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

win32:CONFIG(release, debug|release): LIBS += -LD:/opencv/build/x64/vc15/lib/ -lopencv_world420
else:win32:CONFIG(debug, debug|release): LIBS += -LD:/opencv/build/x64/vc15/lib/ -lopencv_world420d
else:unix: LIBS += -LD:/opencv/build/x64/vc15/lib/ -lopencv_world420

INCLUDEPATH += D:/opencv/build/include
DEPENDPATH += D:/opencv/build/include