Using SSH with X11 Forwarding for Remote Image Display

I personally really enjoy working with the command line and using SSH. It's fast, powerful, and great for development. However, since our research involves medical images, being able to display images remotely is an important (and frequent) task.

When i first tried setting this up on my Windows PC, it didn't work out of the box. After some troubleshooting under the help of ChatGPT, i figured it out — so here are a few tips that might help you too!

1. SSH with X11 Forwarding

When connecting to your remote server, use the -X (or -Y) flag to enable X11 forwarding:

ssh -X user@remote-host

check that the DISPLAY variable is set after login:

echo $DISPLAY 

You should see something like localhost:10.0

2. Install X11 libraries on the remote machine

On the remote host, make sure the necessary X11 packages are installed:

sudo apt uodate
sudo apt install x11-apps python3-tk

To test if it's working, run:

xeyes

if the eyeballs show up, X11 is working! 

3. Local machine must have X11 server (macOS or Windows)

macOS

Install XQuartz 

After install, run XQuartz and reconnect using:

ssh -Y/-X user@remote-host

Windows 

If you're on a Windows system, you'll need to install an X11 server like:

•  VcXsrv
•  Xming    

Here's how you set up VcXsrv:

• Download and install VcXsrv
• Run "XLaunch" 
• Select:
• Multiple windows
• Start with "Start no client"
• Enable "Disable access control" (or configure access if needed)
• Finish and leave it running in the background

Now, to connect:

• Use MobaXterm or PuTTY with X11 forwarding enabled

• Important: Windows CMD and PowerShell donot support X11 forwarding directly. You'll need to use WSL or an SSH client that supports X11.