Tutorials Archives - Page 5 of 19

2017-12-172019-06-25

How to Access Windows Event Log Using C++ with Qt and Win32 API

In this post I’ll share a method you can use to access and read events in Windows operating system, using C++. Note that this method is modified to be used with Qt, but you can easily replace the few Qt classes used in this example and remove the dependency on Qt if you are using any other frameworks. In any case, this method relies on Win32 APIs and will work only on Windows operating system.

2017-11-012019-06-09

How to Build Qt 5.9.2 Static Using MinGW

You can follow the instructions below to build Qt 5.9.2 from sources using MinGW, and statically. To be able to proceed further, you need to make sure you have all the prerequisites on your PC, which are mentioned in this post, then return here.Assuming that you have taken care of all the requirements, you can start by downloading MinGW and Qt 5.9.2 source codes, or take the better and “recommended” route and simply download both of them using the Qt 5.9.2 all-in-one installer for Windows.

2017-10-212019-05-01

Computer Vision with OpenCV 3 and Qt5, Now Available for Preorder

It is one thing to become an author, but it is totally another level of joy, to be published by my most favorite publisher in the computer science industry. So, it is with great pleasure that today I can announce that my upcoming book about OpenCV and Qt is available for preordering on Amazon, and also from PacktPub. It’s titled “Computer Vision with OpenCV 3 and Qt5”, and it aims to teach both computer vision and application development for developers who are familiar with C++ (on an intermediate level), but want to learn about powerful cross-platform frameworks such as Qt and OpenCV with hands-on examples and clear instructions. The book is in its final stages of completion, so I’m also excited to announce that our goal is to make it available by the beginning of 2018 and we are working hard to make it happen. Here are the links to preorder:

https://www.packtpub.com/application-development/computer-vision-opencv-3-and-qt5

2017-10-162019-06-09

How to Build Qt From Source Codes

In this post you’ll find information about how to build Qt from source. We’ll be building the latest version of Qt, released about a week ago, using its source codes, both dynamically and statically and with various customized configurations. So without further ado, let’s start.

2017-08-132019-05-05

How to Build OpenCV 3.3.X for Android

In this post I’m sharing the required steps for building OpenCV 3.3.X (to be precise, OpenCV 3.3.0 which was released about a week ago) for Android. You can also download the pre-built libraries from here but it’s always a good idea to build the libraries yourself in case you want any special configurations such as Nvidia Carotene, OpenCV World and so on. So here it is:

2017-07-262019-05-01

How to Get Past the Infamous “Insufficient Count of Samples” Error in OpenCV Cascade Training

Many people who have tried OpenCV’s traincascade tool know about a very disturbing error which (at least at the moment) seems to have no good solution, but nevertheless this issue has a solution (even if not convenient) so we need to stick to what we have at hand. My Cascade Trainer GUI app which also uses OpenCV as the underlying framework is also seen to produce this error with many users so I decided to discuss this and share my solution with you all, but please make sure you put your comment below if you’ve got any questions or better suggestions. So, let’s get down to it.

2017-06-012019-05-05

How to Rotate and/or Flip (Mirror) Images in OpenCV

In this post I’m sharing a couple of very simple tricks to perform an efficient Rotate or Flip (Mirror) operation on OpenCV Mat images.

2017-05-242019-06-02

How to Use OpenCV in Unity (Example Project)

This is a post that many people have requested recently. I’m going to describe how you can use OpenCV in Unity. Of course we’ll be using official OpenCV libraries and not any assets or existing plugins. For those of you who aren’t familiar with the subject, Unity is a very popular game engine which allows building games, apps and so called experiences with much ease. Unity allows some modified form of JavaScript and also C# for its scripting. In this example project I’ll use C# since that’s the language I’m familiar with but it shouldn’t be hard to adapt this to JavaScript (but you’re gonna do it yourself if needed, sorry) so let’s start.

2017-03-082019-05-05

OpenCV 3.2.0 Pre-Built Libraries for Android

In this post I’m sharing the pre-built libraries and binaries for OpenCV that I use to build Qt/QML and OpenCV powered apps for Android (armeabi-v7a) phones. An example of such application is Quick-Camera-CV which I shared its source codes in a previous post.

2017-02-102019-05-01

How to Use C++/Qt/QML/OpenCV to Write Mobile Applications

I have avoided using QML for long time and always wrote even the most simple applications using Qt Widgets and C++ code but the release of Qt’s Quick Controls 2 and Material Style just made it very irresistible and I had to go for it. Well it didn’t take too long to get a hold of things (for a newcomer) since I had enough programming experience and QML is just too well-structured and easy to learn and use. In this post I’m going to share a project that demonstrates using OpenCV in QML to write beautiful and powerful Android (and other platforms) apps.