ms.Close(); //close the MemoryStream when done

It's a good thing that you close the ms (MemoryStream) but there are two more to dispose.

The bitmap and graphics instances also need to be disposed/closed. The same applies to the NetworkStream but I got the impression that you don't know the using statement that allows you to automatically handle resources so:

NetworkStream stream = getSelectedClient().GetStream();
..
f.Close();

would become:

using(var networkStream = getSelectedClient().GetStream())
{
    ..
} // at this point it will be closed/disposed by the runtime

You can use the same pattern for bitmaps, graphics and anything else that is IDisposable.

ms.Close(); //close the MemoryStream when done

It's a good thing that you close the ms (MemoryStream) but there are two more to dispose.

The bitmap and graphics instances also need to be disposed/closed. The same applies to the NetworkStream but I got the impression that you don't know the using statement that allows you to automatically handle resources so:

NetworkStream stream = getSelectedClient().GetStream();
..
stream.Close();

would become:

using(var networkStream = getSelectedClient().GetStream())
{
    ..
} // at this point it will be closed/disposed by the runtime

The benefit of this is that it will be correctly disposed even if an exception occurs. Without it you would need to write the try/finally yourself (what a using actually does for you (or rahter the compiler))

NetworkStream networkStream = null;

try
{
    networkStream = getSelectedClient().GetStream();
    ..
}
finally
{
    networkStream?.Close();
}

You can use the same pattern for bitmaps, graphics and anything else that is IDisposable.