Actually getting to the image's pixels

[ppersits]

I compiled everything in C++ and it worked, but where is an example of actually getting to the image's pixels? The examples in examples.cpp just say this:

        if (reader->getItemDataWithDecoderParameters(masterId.get(), itemData, itemSize) == ErrorCode::OK)
        {
            // ...decode and display...
        }

But how do I decode?

Thanks in advance.