OpenCV tutorial 4: OpenCV and Qt
Why Stack Overflow recommends it
Stack Overflow users link it when someone asks how to combine OpenCV with Qt or how to build a GUI around OpenCV video capture.
Recommended by 4 people across 3 different months, 2012 to 2016.
What it is
A 40-minute screencast by Chris Dahms, the fourth in his OpenCV series, that rebuilds the earlier console-style program as a Qt application with a graphical interface. It shows how to wire OpenCV video capture and image processing into Qt widgets and QTimer-driven updates.
What people said
Recommends Isira · 2012-11 · Stack Overflow · on “Qt with OpenCV - Which one to download”
When using QT there is a IDE named QT Creator. This gives the option of creating various type of projects such as plain C and Plain c++ projects and many more. So you may not need any other c++ IDE as MSVS express. Download the QT SDK [LINK] to get all the libraries and the IDE together. For example for windows download the exe in named as "Qt libraries 5.0 Beta 2 for Windows (501MB)" If you are going to use OpenCV with QT i recommend OpenCV tutorial 4: OpenCV and Qt [this video] on youtube.
Recommends phyatt · 2012-12 · Stack Overflow · on “(Qt) Unusable window after one button click”
So when using Qt with OpenCV, I would setup the polling using Qt's timers instead of a while loop. There is a pretty good tutorial of using QTimers to interact with OpenCV objects here: [this video] Jump to 35 or 38 minutes into it to see how he writes his classes. Basically, you let Qt do the waiting and timing, instead of having a while loop with a wait call doing the timing. And if possible, let Qt create the windows, and nest the OpenCV windows into Qt's windows so that Qt can manage the events on the windows. Hope that helps.
Recommends user1790875 · 2012-12 · Stack Overflow · on “What Qt GUI Containers to use? Also Related Video Display issue - Windows 7”
@user1824407 : ok. i just found a youtube video on OpenCV + Qt here [this video] while i go through it could you pls provide me with a solution of the problem above?
Recommends scap3y · 2013-11 · Stack Overflow · on “Using OpenCV 2.3.1 with Windows Form Application in visual studio 2010 express”
May I suggest Qt instead of windows form application..? It will give you more freedom for future development and at the same time give you the power to go cross-platform. There is a very nice video tutorial on YouTube [this video] which you can use as a base. Plus, OpenCV and Qt work very nicely together. However, if your bigger app needs windows forms, you could follow this tutorial [LINK] which shows how to integrate OpenCV with windows forms. HTH
Cites user1343762 · 2013-07 · Stack Overflow · on “error while using QT and OpenCV”
i am having the following error while trying to implement my first code with QT and OpenCV. error C2039: 'videoCapture' : is not a member of 'cv' In fact, i was testing the code of this tutorial [this video] . I don't know why QT can not find the OpenCV libraries, well here is the OpenCV part in the project.pro : INCLUDEPATH += D:\\opencv\\build\\include LIBS += -LD:\\opencv\\bin\\Release\ -lopencv_core245 \ -lopencv_imgproc245 \ -lopencv_highgui245 \ -lopencv_ml245 \ -lopencv_video245 \ -lopencv_features2d245 \ -lopencv_calib3d245 \ -lopencv_objdetect245 \ -lopencv_contrib245 \ -lopencv_legacy245 \ -lopencv_flann245
Cites Fabulous · 2016-09 · Stack Overflow · on “How can I detect the position and the radius of the ball using opencv?”
I see you have quite a setup installed. As mentioned in the comments, please make sure that you have appropriate lighting to capture the ball, as well as making the ball distinguishable from it's surroundings by painting it a different colour. Once your setup is optimized for detection, you may proceed via different ways to track your ball (stationary or not). A few ways may be: Feature detection : Via Hough Circles, detect 2D circles (and their radius) that lie within a certain range of color, as explained below There are many more ways to detect objects via feature detection, such as this clever blog [LINK] points out. Object Detection: Via SURF, SIFT and many other methods, you may detect