How to install openCv in Qt

Trav

Hello,

I am looking for context in regards to getting openCv essentially in my application to work. I have managed to do what I would like to accomplish but am taking a learning curve and diving into Qt for lots of obvious reasons and at this point I just am learning and navigating so far what I have found though is to put (see below) into the .pro file but nothing is happening or suggesting when [example ] #include<opencv>

LIBS += -L/usr/local/lib
-lopencv_core /
-lopencv_imgproc /
-lopencv_features2d/
-lopencv_highgui

SGaist

Hi,

You must use backslashes when doing multiline assignments like this one.

Trav

Im using he backslashes just essentially replaced what I had above ****** LIBS += -L\usr\local\lib
-lopencv_core
-lopencv_imgproc
-lopencv_features2d
-lopencv_highgui

But still am having difficulties is there something I'm missing here? I am using Mac OSX... and have accomplished this is Xcode but just doesn't seem to be working is there anything else to configure etc?

SGaist

I meant: use backslashes when marking a new line. For the paths themselves use forward slashes.

What error are you getting ?

Trav

@Trav said:

LIBS += -L/usr/local/lib
-lopencv_core /
-lopencv_imgproc /
-lopencv_features2d/
-lopencv_highgui

2 days ago

sorry for the wait... all I'm getting is opencv.cpp not found... is there solid documentation somewhere on this subject? thank you

SGaist

opencv.cpp not found ? Where's that file coming from ?

Not knowing what your current error relates to I can't give you any recommendation.

Trav

The actual file itself 'openCV ' is located on my desktop... I made a file 'build' inside the folder and then 'lib' where all the files are located ; highgui etc. Is there a crucial step I missed here ? I mean I downloaded openCV installed Cmake by following a tutorial and installed this perfectly fine in Xcode.. But since moving to Qt I have not been able to get the same results.

Trav

Could you please tell me in your case how would you do this if you were using Mac assuming we have Qt installed and openCV...

SGaist

There are several possibilities.

You can use pkg-config or do it like you do currently and provide the INCLUDEPATH and LIBS with the adequate data.

Can you share your complete .pro file ? From the bits you've given, one time you have used the wrong line ending char and the other you are complete missing it.

Example:

LIBS += \
    -L/usr/local/lib \
    -lopencv_core \
    -lopencv_highgui

INCLUDEPATH += \
    /usr/local/include

You should also post the exact error you are having.

Trav

Yes please see bottom for code. If it at all has changed I have been modifying it and tuning it according to different tutorials to see if it'll work etc. But essentially the end result is the same ERROR: opencv.h not found' when using ' #include <opencv.h> or something similar; highgui, core ...

#-------------------------------------------------

Project created by QtCreator 2016-05-15T23:16:25

#-------------------------------------------------

QT += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = cam
TEMPLATE = app

// new
QT += core
QT -= gui

TARGET = RP_openCV_01
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp
mainwindow.cpp

LIBS += -L/opt/local/lib
-lopencv_highgui.3.1.0
-lopencv_core.3.1.0

INCLUDEPATH += /opt/local/include

HEADERS += mainwindow.h

FORMS += mainwindow.ui

Trav

Only error is the error that is indicating the header files are not found " OPENCV.H not found!'

QT += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = cam
TEMPLATE = app

// new
QT += core
QT -= gui

TARGET = RP_openCV_01
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp
mainwindow.cpp

LIBS += -L/opt/local/lib
-lopencv_highgui.3.1.0
-lopencv_core.3.1.0

INCLUDEPATH += /opt/local/include

HEADERS += mainwindow.h

FORMS += mainwindow.ui

SGaist

Shouldn't it be #include <opencv2/opencv.hpp> ?

Trav

Sorry, yes; I have used the #include <opencv2/opencv.hpp> and the error I stated above is still valid

SGaist

Do you mean the opencv.h not found error ?

Trav

Hey, thanks for your help I actually got it and have reproduced the desired outcome... essentially what happened because I am new to Qt & OpenCV etc. It seems I have placed the code before Sources' in the project.pro file which produced the errors... I did this before as well I don't quite understand why it decides to work now but did not before? but essentially I'm good :) thanks for support

SGaist

Good !

In that case, please mark the thread as solved using the "Topic Tool" button so that other forum users may know a solution has been found :)

Solved How to install openCv in Qt

Project created by QtCreator 2016-05-15T23:16:25