Efficient way to send images via WCF?

Question

I am learning WCF, LINQ and a few other technologies by writing, from scratch, a custom remote control application like VNC. I am creating it with three main goals in mind:

The server will provide 'remote control' on an application level (i.e. seamless windows) instead of full desktop access.
The client can select any number of applications that are running on the server and receive a stream of images of each of them.
A client can connect to more than one server simultaneously.

Right now I am using WCF to send an array of Bytes that represents the window being sent:

using (var ms = new MemoryStream()) {
    window.GetBitmap().Save(ms, ImageFormat.Jpeg);
    frame.Snapshot = ms.ToArray();
}

GetBitmap implementation:

var wRectangle = GetRectangle();
var image = new Bitmap(wRectangle.Width, wRectangle.Height);
var gfx = Graphics.FromImage(image);

gfx.CopyFromScreen(wRectangle.Left, wRectangle.Top, 0, 0, wRectangle.Size, CopyPixelOperation.SourceCopy);

return image;

It is then sent via WCF (TCPBinding and it will always be over LAN) to the client and reconstructed in a blank windows form with no border like this:

using (var ms = new MemoryStream(_currentFrame.Snapshot))
{
    BackgroundImage = Image.FromStream(ms);
}

I would like to make this process as efficient as possible in both CPU and memory usage with bandwidth coming in third place. I am aiming to have the client connect to 5+ servers with 10+ applications per server.

Is my existing method the best approach (while continuing to use these technologies) and is there anything I can do to improve it?

Ideas that I am looking into (but I have no experience with):

Using an open source graphics library to capture and save the images instead of .Net solution.
Saving as PNG or another image type rather than JPG.
Send image deltas instead of a full image every time.
Try and 'record' the windows and create a compressed video stream instead of picture snapshots (mpeg?).

Efficient way to send images via WCF?

7 Answers