The website can use any image that is formatted as a JPEG, GIF or PNG file.
If you don't want to use dozens of yarns at once , it's worth tweaking your image to reduce the number of colours in it. I started with the Robot image from this topic
, and used Photoshop to add extra space around it, and cut down the number of shades in the image.
Uploading the image to Pics To Knits was actually quicker and easier than uploading an image here.