How to create a DU2 file with Photoshop/other tool and Imenhance by Percy/Light.
 
  1. Load your photo to Photoshop (or other tool) scale and crop the image to 832*546 pixels, save as 24-bit PNG

  2. Open up Imenhance in your Web browser and drop the image to the web page

  3. Do these REQUIRED base settings:
    • Colourspace: Atari ST
    • Screen size: 832*273 (Atari ST/STe Med-Res Overscan)
    • Max colours: 4

  4. Laborate with the expert settings to get your preferred result

  5. Save the finished photo:
    • Download the ENHANCED.DU2 file or the DITHERED.DU2 depending on which one you prefer
    • Also save the corresponding PNG image by right clicking the image (for Demozoo screenshot)

  6. Send both the DU2 and PNG image in your compo submission
Good luck!
 
Video showing the above process