I would like to know which library to use, which is easy to install for both Windows and Linux, to manipulate images (of type png, jpg, etc) in C / C ++?
I would like to open and save it in an array to be able to work with this data as well as show it in a window afterwards (display the image).
You just need to do this. It does not have to be an OpenCV of life.
The ideal would be to work directly with libpng or libjpeg. It's true that they are libraries that, at first glance, seem complex and esoteric but they give you what it's all about - open an image of their format and give you a pointer to an array with the image data. An example file reading with libpng: link
If you do not want to work with the low level of the various image load libraries, you can use something that involves them in an abstraction layer, such as ITK, OpenCV, or VTK. image display). SDL would also be a good alternative and is simpler to use than the ones I mentioned above.
As for ease of installation, it depends on whether or not you use CMake. If you know how to use Cmake every c / c ++ library becomes easy to use, simply by the .h directory and the pro .lib path in Cmake according to his rules. If you do not know how to use Cmake, you will have problems.
You could try the library CxImage .
Documentation: link
In this site contain all the links of libraries , in the Image Processing tab, you can find other viable options.
