Take a photo using white colors. Upload to Picasa.
Picas has tools to lighten the photo.
Convert it to a black and whte image.
Move the image to Microsoft Paint and trace the rope with a curving black line.
It's helpful to zoom the image to 200% and listen to TED.com or NPR.org in the background.
Save the image and return to Picasa. Once the image is viewed in Picasa again, use the edit tool to completely whiten the original photographed image.
Return to Paint if a final color finish is desired.