How to Build OpenCV 4.X for Native Android Development

For a number of different reasons, you might want/need to build OpenCV from scratch instead of using the pre-built and official libraries provided by OpenCV. Since you’ve ended up reading this post, there’s a good chance that you already know why you might need to do this, but if you don’t, you can check out my similar post from a couple of years ago for some answers on this. That post was based on OpenCV 3.3 which is considered out-of-date these days, especially with OpenCV 4 out in the market (OpenCV 4.0.1 at the time of writing this article), so I decided to write a new tutorial to address some of the differences. So without without further ado, here we go.

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A Simple Script to Build OpenCV 3.4.3 for Windows

Over the years I have written quite a few guides and tutorials that describe building OpenCV from sources for Windows, however they were mostly done using the GUI. It means you’d have to be using CMake GUI to set some parameters and then a few other actions and you’d end up building OpenCV using Visual Studio like any other VS solution. Even though it’s quite simple to build OpenCV like this, you can’t automate it and you need to perform all the required actions manually. In this post though, I’ll be sharing a few simple commands that can be put inside a batch script that will allow you to build OpenCV for any platform you like, simply by executing (or double clicking) that script!

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Adding External Libraries to Qt Projects

As simple as it sounds, most of the time it’s a hassle to add the required libraries to your Qt projects. You have to add the include path, the libraries and if you are aiming to have a cross-platform project, you need to account for Windows, macOS and Linux operating systems separately. Well, there are a couple a methods to simplify this a bit which I’ll describe in this tutorial.

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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.

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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:

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How to Build Qt 5.7 Statically Using MSVC14 (Microsoft Visual Studio 2015)

In this post I will describe how to build Qt 5.7 statically for Windows using MSVC 14 compiler or in other words Microsoft Visual C++ 2015 which is included in Microsoft Visual Studio 2015. Quite obviously you need to install Microsoft Visual Studio 2015 (Community edition is free) before continuing with this guide. You can find it here:

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How to Build OpenCV 2.4.13 Static/Dynamic with MSVC2010

OpenCV 2.4.13 was released just a few days ago and as a tradition I had to check if a static build with Microsoft Visual C++ 2010 (MSVC2010) 32-bit produced any errors or not. Fortunately, everything went quite smoothly (except a few common warnings here and there) and I was able to successfully build it so if you need to build the latest OpenCV release statically using MSVC2010 you can follow the steps below:

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