CMake - how to add a missing library easily?

Question

I'm trying to install Darknet from here https://github.com/AlexeyAB/darknet using these instructions:

Looked easy enough, I installed all the required pre-requisites...

I get the error "Could NOT find JPEG (missing: JPEG_LIBRARY JPEG_INCLUDE_DIR)" with CMake, I had an error like it before for Zlib, which I was able to install using this .bat file https://github.com/horta/zlib.install/blob/master/install.bat

What is the simplest way to include this library called' JPEG' within Cmake's scope of libraries?

So, do you have JPEG library installed? If not, you need to install it. E.g. via vcpkg. — Tsyvarev, Dec 05 '20 at 19:40

score 2 · Accepted Answer · answered Dec 07 '20 at 08:08

On Windows, the easiest way to manage C++ dependencies, by far, is vcpkg. Follow the directions on their repo to install:

> git clone https://github.com/microsoft/vcpkg
> .\vcpkg\bootstrap-vcpkg.bat

Then install libjpeg as well as any other dependencies:

> .\vcpkg\vcpkg install libjpeg libjpeg-turbo:x64-windows

If you need 32-bit, install libjpeg-turbo:x86-windows additionally (or instead).

Then, when trying to build Darknet, configure CMake with:

> cmake -DCMAKE_TOOLCHAIN_FILE=X:/path/to/vcpkg/scripts/buildsystems/vcpkg.cmake ...

On the other hand, vcpkg has a darknet port, so you could just run:

> .\vcpkg\vcpkg install darknet[full]:x64-windows

Doesn't answer the question you asked, but maybe it's what you want, anyway.

Thanks so much, I was really struggling to find what the 'JPEG' library was called or where to get it from, your solution worked for me thankyou! I actually hit this error as something went wrong with vcpkg installing dependencies also but I couldn't reproduce that as a bug when I went back to do it again luckily. — ROBYER1, Dec 08 '20 at 08:28

1 Answers1