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User forums => Using Code::Blocks => Topic started by: jhongramaticus on April 14, 2026, 09:49:54 am

Title: OpenCV error in code::blocks
Post by: jhongramaticus on April 14, 2026, 09:49:54 am
I'm trying to use OpenCV (version 4.12.0) in Code::Blocks (version 25.03). When installing OpenCV, I used CMake to generate the libraries in Code::Blocks and Mingw. Once I obtained openCV.cbp, I compiled it in Code::Blocks to generate the libraries. After that, I opened code::blocks<<file<<new<<project<<openCV project<< next<<next<<next<< and I got the following error:
 
Code
the lib path you entered seems invalid, can't find files C:\opencv\build\x86\mingw\lib\libopencv_core121.dll.a or C:\opencv\build\x86\mingw\lib\libopencv_core121d.dll.a 

I created the x86<<mingw folder so that cmake would generate the files in that location. Despite searching for help on Stack Overflow and other sites, I found no answers. I renamed the library libopencv_core4120.dll to libopencv_core121d.dll.a and it worked fine until yesterday. Now I've deleted code::blocks and OpenCV, regenerated the libraries, and when I try to use any program that has an OpenCV library, I get the message:

Code
"Code execution cannot continue because libopencv:core4110.dll was not found. This problem can be solved by reinstalling the program." I got the same message for libopencv_imgcodecs4120.dll and also libopencv_imgproc4120.dll.


Before attempting to create code using OpenCV's Code::Blocks project, I added it only to Settings <<Compiler <<Linker Settings and the directory to Settings <<Compiler <<Search Directories. I've since removed everything, but I'm still getting the same errors, both when creating a project using OpenCV's code::blocks<<file<<new<<project<<openCV project<< next<<next<<next<< and when creating a regular file just mentioning the OpenCV libraries. Sometimes, even a simple "Hello World" code won't compile because of these OpenCV problems.
Title: Re: OpenCV error in code::blocks
Post by: Miguel Gimenez on April 14, 2026, 10:11:30 am
There is a double backslash in the search path:

Code
mingw\\lib\libopen
Title: Re: OpenCV error in code::blocks
Post by: jhongramaticus on April 14, 2026, 04:24:10 pm
Fixed, thank you
Title: Re: OpenCV error in code::blocks
Post by: Miguel Gimenez on April 14, 2026, 06:38:43 pm
Did you fix it in the project or only in the post?
Title: Re: OpenCV error in code::blocks
Post by: stahta01 on April 14, 2026, 10:40:47 pm
Something to try is
Project -> Build Settings
Select the project in left hand window
Linker Settings
Then remove the version variable of "CV_VERSION" also remove the "$" sign and braces before and after.

I then got an error I did not understand.

Tim S.
Title: Re: OpenCV error in code::blocks
Post by: stahta01 on April 14, 2026, 11:32:20 pm
Rereading your message implies that the error is during the wizard.

Right click on the wizard and you can edit it.

You need to state what are the names and path to the DLLs and DDL import libs:

I edited the wizard for me by removing [_T("\\libopencv_core") +].

Code
        local test_release_lib_file = lib_nomacro + _T("\\libopencv_core") + VersionString + _T(".dll.a");
        local test_debug_lib_file = lib_nomacro + _T("\\libopencv_core") + VersionString + _T("d.dll.a");

But that was because the import library did not have the version in it.

Tim S.