qt,opencv,mingw , Must compile Opencv with Mingw in order to use in QT under Winodws?

Must compile Opencv with Mingw in order to use in QT under Winodws?


Tag: qt,opencv,mingw

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How to link opencv in QtCreator and use Qt library

All of them are using Mingw to compile Opencv through Cmake. If I want to use Opencv in QT, is compiling with Mingw the only way?

I have this question because I already compiled my Opencv 2.4.11 with Visual Studio 2013(in Cmake---Visual Studio 12 2013 Win64), when I follow the directions setting up the INCLUDEPATH and LIBS in QT


-L"C:\\opencv2.4.11\\opencv\\build\\x64\\vc12\\lib" \
    -lopencv_core2411 \
    -lopencv_highgui2411 \
    -lopencv_imgproc2411 \
    -lopencv_features2d2411 \
    -lopencv_calib3d2411 \

I get this error message :

C1083:Cannot open include file:'opencv2/opencv.hpp': No such file or directory


You can compile it with Visual Studio as well. The opencv includepaths already have the opencv2 part of it. So the correct includepath would only be:



Surface normal on depth image

How to estimate the surface normal of point I(i,j) on a depth image (pixel value in mm) without using Point Cloud Library(PCL)? I've gone through (1), (2), and (3) but I'm looking for a simple estimation of surface normal on each pixel with C++ standard library or openCV. ...

Is there a way to prevent rounding in opencv matrix divison

I have an integer matrix and I want to perform an integer division on it. But opencv always rounds the result. I know I can divide each element manually but I want to know is there a better way for this or not? Mat c = (Mat_ <int> (1,3) <<...

How to pass QString variable to QFile?

getData gets the chosen file from a QTreeView and displays it on label 'test', enables the 'Apply' button, which when clicked calls setTheme void OptionsDialog::getData(const QModelIndex &index) { QString selected = model2->filePath(index); ui->test->setText(selected); ui->pushButton_apply_theme->setEnabled(true); } void OptionsDialog::setTheme() { //char *file = selected->toLatin1().data(); //const std::string file = selected->toStdString(); QFile qss(selected); qss.open(QFile::ReadOnly);...

adaptive thresholding ---ValueError: too many values to unpack

I'm pretty amateur at image processing. I could successfully do normal thresholding but however I'm facing an error in Adaptive Thresholding. Here is my code: import cv2 import numpy as np img = cv2.imread("vehicle004.jpg") img = cv2.medianBlur(img,5) gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY) _,th2=cv2.adaptiveThreshold(gray,255,cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY,11,2) cv2.imshow("window2",th2) cv2.waitKey(0) cv2.destroyAllWindows() Error Message: line 7, in <module>...

How to change the opacity of Qt MainWindow?

How to change the opacity of the Qt MainWindow by some values? My main window contains nothing but just somehow I need to change the opacity using keystrokes. It looks like this now. I tried to set using this->setWindowOpacity(0.5); didn't get anything opacity effect. ...

How to call OpenCV's MatchTemplate method from C#

I'm trying to get the template's position on the image using OpenCVSharp library from NuGet. Here is the code I've wrote: var image = Cv.LoadImage("Image.png"); var template = Cv.LoadImage("Template.png"); var w = (image.Width - template.Width) + 1; var h = (image.Height - template.Height) + 1; IplImage result = new IplImage(w,...

Is there a way to prevent Qt slider dragging beyond a value?

I have implemented the interface where the user is drawing a frame and then moving to next frame which will increment the slider value by 1. User can also increment or decrement the slider value. But, if user has drawn only upto frame 20 then user should not be able...

How can I wrap text in QGraphicsItem?

1) How can I wrap text in a QGraphicsTextItem to fit a fixed rectangle, with width and height ? Right now I am experimenting with creating a text, getting its bounding rectangle, and resizing it to fit the box - but I can't get wrapping. class TTT: public QGraphicsTextItem {...

Unable to connect to mariadb database server with qt 4.8.5 and Ubuntu 12.04

I use the following code to connect to a MySQL server database. QSqlDatabase db_Server = QSqlDatabase::database("Test"); //find mysql driver db_Server = QSqlDatabase::addDatabase("QMYSQL","Test"); db_Server.setHostName("188.**.***.***"); db_Server.setPort(3306); db_Server.setDatabaseName("Test"); db_Server.setUserName("Test"); db_Server.setPassword("*********"); bool ret = db_Server.open(); if(ret) qDebug() << "Database open" else qDebug() << db_Server.lastError().text(); Lately they changed the server to mariadb and I assumed...

Update bindings to var properties in QML

If you take a look at this page it notes that bindings to var properties are not automatically updated when the object changes: Item { property var car: new Object({wheels: 4}) Text { text: "The car has " + car.wheels + " wheels"; } Component.onCompleted: { car.wheels = 6; }...

How to add a gif image in the statusbar Qt [closed]

I'm pretty new to Qt and I was told that I can add a gif image to the status bar using the QMovie class. Can anyone tell how it can be done and is there any other way to do this too?

Sending live video frame over network in python opencv

I'm trying to send live video frame that I catch with my camera to a server and process them. I'm usig opencv for image processing and python for the language. Here is my code client_cv.py import cv2 import numpy as np import socket import sys import pickle cap=cv2.VideoCapture(0) clientsocket=socket.socket(socket.AF_INET,socket.SOCK_STREAM) clientsocket.connect(('localhost',8089))...

Repeat state on mouse click QML

Within the code I have a State, a Transition and a RotationAnimation defined. After the property change takes place, i.e. after the rotation is set to 360, the onClicked handler is rendered mute and the animation will never be played again after subsequent MouseArea clicks. Here is my current code:...

C++ & Qt: Random string from an array area

In my small Qt application, I want to pick a random string out of an array after I clicked on a button. I've read many threads but nothing works for me. So in my slot there's an array with several strings in it. I also implemented <string>, <time.h> and srand....

Copy text and placeholders, variables to the clipboard

In my application I want generate random numbers or strings with a text in front of it. It is important for me that the text won't appear in my window, but instead gets copied to the clipboard. int randomnumber = rand() % 46 + 1; QClipboard *cb = QApplication::clipboard(); cb->setText("Just...

Id in database using qt

I am new to qt. I have created a table in sql, and what I'm trying to do is to give an id whenever user adds data. For the first thing inserted it will be 1, second 2 and so on. So how to check what number was the last...

How can I override the member of (->) operator of a base class

Background: I have Qt generated UI classes with no common ancestor. I am subclassing a class (say, "Door") that uses one of these UI classes, and the derived class ("OakDoor") will use a different UI class, although much of the UI elements will have the same name. Until now I...

Error : Cmake can't generate openCV

I am trying to instal opencv C++ with codeBlocks in Windows 8 by following this http://kevinhughes.ca/tutorials/opencv-install-on-windows-with-codeblocks-and-mingw/ but I am blocked in step 4.when I try to generate Cmake I have this Error : CMake Error: CMake was unable to find a build program corresponding to "MinGW Makefiles". CMAKE_MAKE_PROGRAM is not...

opencv window not refreshing at mouse callback

I am trying to draw with mouse move in an opencv window. But when I draw, nothing draws on the window. When I try to close the window from the cross in the topleft(ubuntu), it opens a new window which it should be as I haven't pressed escape, and in...

OpenCV - Detection of moving object C++

I am working on Traffic Surveillance System an OpenCv project, I need to detect moving cars and people. I am using background subtraction method to detect moving objects and thus drawing counters. I have a problem : When two car are moving on road closely them my system detects it...

connecting signals and slots with different relations

First of all I'd say I'm a noob to GUI programming. I use Qt 5.4. I came up with this code while watching voidRealms videos. connect(ui->horizontalSlider,SIGNAL(sliderMoved(int)),ui->progressBar,SLOT(setValue(int))); Obviously this connects slider movement with progressbar fill. This actually works like progressbarfill <- slidermovement. How can I make into a different relation? Like...

change QDir::rootPath() to program running path?

I have a Qt FTP server that selects C:/ as root path. I'm trying to change that to select the starting program location path. For example: If ftpserver.exe is located in H:/programs/ftpserver.exe, it must automatically set the ftp root path to H:/. Code: ui->lineEditRootPath->setText(settings.value("settings/rootpath", QDir::rootPath()).toString()); Code: void MainWindow::on_toolButtonBrowse_clicked() { QString...

Using QSimpleXmlNodeModel and QTreeView

I've been looking at ways to populate a QTreeView with data from an XML file. The XML will be simple. I've come across QSimpleXmlNodeModel and have been trying to figure out if this is suitable for my needs, but can't find any examples of its use. Can someone point me...

Qstring error. Saving from Textpool to string

I've been trying to make simple 'typing game' where program is checking if input = showcased word. I'm trying to use Qt GUI, so I've placed two text widgets, and "play" button. However, there is a problem with string (or QString). Error: no match for 'operator=' (operand types are 'QString'...

Return const reference to local variable correctly

Additionally to the answers 1, 2, 3 and GotW88, assume the following methods QString createString() { return QString("foobar"); } const QString& getString() { return createString(); } This will yield the famous "warning C4172: returning address of local variable or temporary" with VS2013. Now if i changed the second method to...

Pro file directive: copy target to folder at build step

I have a TEMPLATE = subdirs project with 6 subprojects which build in specified order. I would like to copy the output file of project1 (it's target) to some folder. This folder is passed with LIBS += -L to project2 and project2 may use this file as a static library....

Customizing QDateEdit style

How can i get the appearance of QDateEdit as shown on the image? I tried changing the stylesheet, but I dont know how to achieve the spacing between the button and the edit, nor how can I change the down arrow button....

Updating ac value for Qtimer

I am using qt tool for mini2440. I make a gui for i2c adc having starti2c and stopi2c. All things are working well: it reads value of signal when starti2c button press, but I want this value to be updated. I know that Qtimer can be used, but how can...

How to set User Agent in QtWebEngine QML application

NOTE: I was able to do that on QtWebKit QML using the QtWebView extension. Here I am interested in using QtWebEngine. My simple test application import QtQuick 2.1 import QtQuick.Controls 1.1 import QtWebEngine 1.0 ApplicationWindow { width: 800 height: 600 color: "lightgray" visible: true WebEngineView { id: webview url:...

Dividing main function into other functions in opencv using c++

I am learning opencv using c++. As I don't have any background knowledge in c++.I am learning it parallel with opencv. Here is my doubt.My main program is very big.So,I want to divide it into small functions and call them whenever necessary in a loop using conditional statements.I have searched...

Change attribute value of an XML tag in Qt

I'm trying to change the language attribute of a .ts file in Qt using Qt itself. Here is the sample XML format. <?xml version='1.0' encoding='utf-8'?> <!DOCTYPE TS> <TS language="es_ES" version="2.1"> ... </TS> I have tried different ways, but no luck. Here are the methods I used. FileIOError FileIO::changeLanguageOfTsFile( QString tsFileName,...

How to avoid user to click outside popup Dialog window using Qt and Python?

I created a Dialog window using Qt Creator and Python. I would like that Window stays on the top of my Gui AND avoid users to click outside that Dialog Until this dialog was closed.

OpenCV FAST corner detection SSE implementation walkthrough

Could someone help me understanding the SSE implementation of the FAST corner detection in OpenCV? I understand the algorithm but not the implementation. Could somebody walk me through the code? The code is long, so thank you in advance. I am using OpenCV 2.4.11 and the code goes like this:...

Extracting Points from Lines using OpenCV

I am trying to extract points from a line on an image using openCV in C++ Language. The line is programmed to display on the image, but I need to know how do you extract points from line and input it into a text file?

QWidget.paintevent() vs QLabel.setPixmap()

I am trying to grab a widget and show it in another widget. Which one is less expensive? 1- using QWidget.paintevent() void MonitoringWidget::paintEvent(QPaintEvent *event) { if (m_mirrorWidget){ QPixmap mirrorPix = m_mirrorWidget->grab(); QPainter p(this); // p.drawPixmap(this->rect(),mirrorPix,mirrorPix.rect()); p.drawPixmap(ui->mirrorFrame->geometry(),mirrorPix,mirrorPix.rect()); update(); } return; } 2- QLabel.setPixmap()? QLabel mirrorLabel; QPixmap mirrorPix = m_mirrorWidget->grab(); mirrorLabel.setPixmap(mirrorPix )...

Rotating a Label In Qt with Python

I'm somewhat new to Qt and was wondering how to rotate a Label that has a pixmap inside of it. I've tried somethings like this: def paintEvent (self, event): t = QtGui.QTransform() image = QtGui.QImage(_fromUtf8(":/icons/BOOM_OUT.png")) pixmap = QtGui.QPixmap.fromImage(image) self.label.setPixmap(pixmap) t.translate(400,300) t.rotate(45) p = QtGui.QPainter(self) p.setTransform(t) p.drawPixmap((-pixmap.width()/2),(-pixmap.height()/2), pixmap) p.end() I know...

QT Combo Box of Line Pattern

i want to make a line pattern combo box in Qt same as it is shown in the picture , please tell me is it possible to make a combo box in Qt like shown in the picture. Any help would be appreciated Regards ...

OpenCV - Method 'knnMatch' could not be resolved

I have just a little problem with the right resource. I am using opencv 2.4.8 and I couldn't find the right resource for knnMatch(). I tried the following which didn't work: #include "opencv2/core/core.hpp" #include <opencv2/nonfree/features2d.hpp> #include "opencv2/nonfree/nonfree.hpp" #include <opencv2/ml/ml.hpp> //#include "opencv2/features2d/features2d.hpp" //#include <opencv2/legacy/legacy.hpp> Can someone say me the right resource?...

What does QHeaderView::paintSection do such that all I do to the painter before or after is ignored

This question is further development of this post and is different, though may seem similar as this one. I am trying to reimplement QHeaderView::paintSection, so that the background returned from the model would be honored. I tried to do this void Header::paintSection(QPainter * painter, const QRect & rect, int logicalIndex)...

How to differentiate a QNetworkReply is aborted or not?

I have the following code: connect(&netMgr, SIGNAL(finished(QNetworkReply*)), this, SLOT(loadFinished(QNetworkReply*)), Qt::UniqueConnection); reply = netMgr.get(qheader); How could I tell whether the loadFinished(); slot is triggered by calling reply->abort() or not?...

best way to create a mat from a CIImage?

I am using CIDetector to detect faces, then using OpenCV on the lower half of each face to detect the size of any smiles. I am using the below code to create the cv::mat which OpenCV can perform the detection on, as you can see the image goes through the...

Camera Calibration with OpenCV: Using the distortion and rotation-translation matrix

I am reading the following documentation: http://docs.opencv.org/doc/tutorials/calib3d/camera_calibration/camera_calibration.html I have managed to successfully calibrate the camera obtaining the camera matrix and the distortion matrix. I had two sub-questions: 1) How do I use the distortion matrix as I don't know 'r'? 2) For all the views I have the rotation and...

How can I have an animated system tray icon in PyQt4?

I am trying to create an animated systray icon for a pyqt4 app but am having trouble finding any examples in python. This is the closest I can find but it's in C++ and I don't know how to translate it over: Is there a way to have (animated)GIF image...

How to create thumbnails using opencv-python?

I'm trying to downsample my image(using anti-aliasing) using Python-Pillow's im.thumbnail() method. My code looks like: MAXSIZE = 1024 im.thumbnail(MAXSIZE, Image.ANTIALIAS) Can you tell me some alternative in opencv-python to perform this re-sizing operation ?...

OpenCV Save a Mat as Binary (1-bit depth) TIFF

Suppose we have a Mat after applying the OpenCv's Imgproc.adaptiveThreshold: Mat srcImage = ...; Mat binaryImage = new Mat(); Imgproc.adaptiveThreshold(srcImage, binaryImage, 255, Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C, Imgproc.THRESH_BINARY, THRESHOLD_BLOCK_SIZE, 10); When I save the binaryImage using Highgui.imwrite: boolean isOk = Highgui.imwrite("sample.tiff", binaryImage); Everything is ok except that output TIFF is not actually a binary...

Sending a Mat object over socket from Java to Java

I understand Sockets over Java and sending Int,String,bytes etc over it. What i just want to know is that is there a way to decode a Mat object to byte array and then send it over java socket and then retrieve back the Mat object from the byte received? Till...

Must compile Opencv with Mingw in order to use in QT under Winodws?

I've visit these blogs https://zahidhasan.wordpress.com/2014/08/19/qt-5-3-1-64-bit-mingw-windows/ How to link opencv in QtCreator and use Qt library http://www.cnblogs.com/grandyang/p/4328896.html All of them are using Mingw to compile Opencv through Cmake. If I want to use Opencv in QT, is compiling with Mingw the only way? I have this question because I already compiled...

Visual Studio 2013 LINK : fatal error LNK1181: cannot open input file

I am using Visual Studio 2013. I'm trying to build some code given to me from my professor and I keep getting this error: LINK : fatal error LNK1181: cannot open input file 'C:\Users\manduchi\Documents\eyegaze\EyeGazeDemo..\Libraries\OpenCV\lib\opencv_core249.lib' However, on my computer opencv_core249.lib is located somewhere else. I've tried updating the linker directories to...

Align horizontalcenter in Column

Column documentation explains how to achieve this: However, I would like to achieve this: That is, all items inside the Column should be horizontally aligned to the center. anchors.horizontalCenter: parent.Center does not work. How can I obtain the desired result?...