OpenCV - How do I get started? - c++

I just don't seem to be able to get OpenCV to work properly. Here's what I want to accomplish:
Use CodeBlocks (which I installed using codeblocks-10.05mingw-setup.exe) with OpenCV (installer: OpenCV-2.4.2.exe) on my Windows x64.
I've tried a lot of different configurations which will only bother you if I posted them all, so I hope you don't mind if I just ask the simple question: how do I get this to work?
I think I'm missing the smallest detail right now, so a detailed description of how to get started would be welcome.

If the OpenCV installer did the job, you should have by now OpenCV libraries and headers already installed in your system.
I would then go ahead and try to compile a hello world basic code, like the one you can get from here. If you would like to program using an IDE, like VisualC++ in Windows, you can follow this guide that will help you setting up the environment.

OpenCV team just introduced their new web site. There you can find Introduction to OpenCV section with installation instructions, including detailed instructions for Windows. Don't forget to cleanup your system before installation to avoid problems with mixing different install options. If you still can't get it working with CodeBlocks, follow Dan's advice and try compiling from command line.
When you are done with installation, go on and read there great new tutorials!

Related

Configure wxwidgets with Codeblocks

I want to build C++ GUI programs using Codeblocks+Wxwidgets+cmake. I tried to configure Wxwidgets with codeblocks IDE following the instructions given in the wxWidgets Discussion Forum as well as other Youtube tutorials.
I followed the youtube tutorials below.
Youtube tutorial
But, when 'DEBUG' and 'RELEASE' are being built, it keeps showing some kind of errors. As a result, the building was failed.
Please help me to solve this or suggest another easy way to do C++ GUI projects.
Thank you!
There is an excellent document explaining how to set up C::B with wxWidgets. It can be found here.
It is not about CMake-thingy, but it is written with enough details to help people understand how to setup the IDE.
So I suggest to delete C::B, delete wxWidgets, delete all projects you setup before and start all over, following the instructions from PB to a T.
If you hit a wall or something will not work - please comeback with the exact explanation.

How to install Qt to work with OpenCV and Visual Studio 2022

I am sorry if this question is already asked but, from every source I have read on google so far they don't cover the most latest versions and I am having a lot of trouble figuring this out.
I have a VS code for detecting faces and saving the ROI onto the desktop. Now, I need to add the functionality for force capture and need to employ GUI for it which openCV is not good enough for. I have been told to use Qt. For more than a week now I have been stuck at simply installing Qt and getting it to work. If anyone could help me out in-line with my project's purpose I would greatly appreciate it.
Every time I install I get some sort of different error which I am not able to understand (complete beginner here), the latest one I got was that Qt could not find the "Kit", even though the dialog box displayed the available ones (Mingw 2022).
Thanks in advance!

MySql connector-c++ wont link in QtCreator but works fine locally on raspberry pi3

Firstly, thank you in advance for at least reading this question.
Secondly, feel free to call me an idiot if this is a "no brainer"
Now down to the issue at hand...
I am running Ubuntu 16.04 (64bit) with QT Creator as my IDE and on the whole it works great. I can cross compile for the Raspberry Pi3 (running raspbian) and also compile plugins for X-Plane.
Everything was going great until I needed to implement MySql into my project. That's when it all went south.
I can not use the Qt library for this as X-Plane does not like anything Qt related in its plugins. But that is fine, I have connector-c++ working on that machine and it connects to my MySql server and does everything it's supposed to.
I think I have read just about every forum and watched every youtube video on this but can not get Qt Creator to compile with connector for the raspberry pi.
I wrote/compiled a test app locally (with g++) on the pi and it works great. However for some reason (government plot maybe?) it refuses to link the libraries when compiling under Qt Creator.
The error I get when compiling in QtCreator is:
undefined reference to `get_driver_instance'
Currently,
I have followed the instructions for setting up a cross compiler here:
https://wiki.qt.io/RaspberryPi2EGLFS
Downloaded the connector code from here:
git clone https://github.com/mysql/mysql-connector-cpp
I have followed the instructions for compiling connector-c++ here:
https://dev.mysql.com/doc/connector-cpp/en/connector-cpp-installation-source-unix.html
And I have banged my head 1000x on a brick wall here:
(picture of blood stained wall not available)
Also, I have tried compiling connector on my Ubuntu pc with paths to the pi's sysroot etc. but i think it made a 64bit version which causes Qt Creator to have a dummy spit about "unrecognized format".
I am hoping that this is just me having a "senior moment" and that someone can point me in the right direction.
To save putting up irrelevant logs/code I will wait until someone asks for it and then copy/paste what they need.
Again, thanks in advance and know that I will be eternally grateful for any light on this matter (preferably before I go even insanerer)
Well after 2 weeks of pain, I have solved this problem. Here is what I think is the issue:
Firstly, I found that mysqlcppconn is not needed (at least for me) and used the mysql libraries in /usr/lib
Secondly, the symlinks to libmysqlclient.so.6.0.22 were by default:
libmysqlclient.so.6 -> libmysqlclient.so.6.0.22
The compiler was looking for libmysqlclient.so which didn't exist. So I created the link (libmysqlclient.so -> libmysqlclient.so.6) and it worked!!
Thanks to all who helped.

VSCode c++ configuring for vc toolchain

I'm trying to start a work in vscode , latest C++ plugin version supports ms debugger, so as I'm mostly working under windows it was a signal to try this.
c++ tools plugin from MS and cmake tools were installed.
my test project was however not built . the problem is clear , but I need an advice from experienced vscode users how to solve this right.
cmake doesn't see vc compiler.
(after using QtCreator) I expected that vscode could detect vc installation... however that's not so. ok, I have a two ways:
fill environment variables INCLUDE/LIB/PATH with a headers, libs and binaries
just run vcvarsall.bat x64
Second way is a simple and reliable. so final question is:
how to run .bat at the begining of vscode start?
(I don't mean write another bat/cmd, prepare the environment and run vscode inside the same script after that)
Although the question is fairly old, I'll try to give a useful answer, in case others stumble across, just like I did.
I believe what you are trying to achieve is not possible. Code inherits the environment it was started with. If you did not launch it from a developer command prompt, you will not be able build and debug. (Building might be possible if every task first starts the vcvarsall.bat, but that slows things down by a lot. Debugging I think will still not work.)
If you are willing to, you can check out vector-of-bools CMake Tools extension which does build automation as well as automatic MSVC detection. It builds using CMake (thus you need to write your build scripts using CMake), but it will take care of building just by pressing F7, like what most VS users are familiar with.

OpenCV in Code::Blocks: The application was unable to start correctly (0xc00000be)

I set up OpenCV with Code::Blocks as per this tutorial: http://kevinhughes.ca/tutorials/opencv-install-on-windows-with-codeblocks-and-mingw/.
I've got as far as building the test program at the end successfully, but when I try to run it I get the following error: "The application was unable to start correctly (0xc00000be). Click OK to close the application."
The one thing that is certainly different from the tutorial for me is that I'm working with OpenCV 3.0.0, Code::Blocks 13.12 and the latest version of mingw (number not obvious from their website or the installer).
I found that other people had had this problem in the past, e.g. The application was unable to start correctly (0xc00000be)
However, it has been a long time since that thread was active, I'm working with newer versions of the software and, most importantly, the answer given there didn't help (I compiled openCV with the same mingw that I'm using with Code::Blocks), so I thought this question would be worth asking (sorry if it's not, I'm rather new to this).
Could anybody suggest a fix that might get rid of this error?
A few other things to note:
I didn't download the Code::Blocks that came with mingw as I was advised against it, I got them separately as per the tutorial
I have installed OpenCV and Code::Blocks on my E: drive, though mingw is still on my C:.
I have added both mingw and OpenCV to my PATH variable, and mingw to my Path variable
I have linked the libraries in both the main compiler settings for Code::Blocks and the Build Options of my project.
I'm working from a 64-bit Windows 7 Laptop, but I have done everything 32-bit style as advised in the tutorial.
Thanks in advance!
So, one solution I've found to this problem is to copy all the .dll files from "...\opencv\build\x86\mingw\bin" to the project file (build directory).
Having done that, the project will run fine. This still doesn't (directly) explain why it wont run without those files (at least, several sources including the tutorial imply it should), and so isn't really optimal. I will continue to look for a solution for this so I don't have to clutter every opencv project I make with the .dlls.
However, for anyone simply wanting to get stuck into coding who is having this problem, I recommend that solution.