Data outdated.

to see in Gimp, use from an image menu: Windows → Dockable Dialogs → Channels; then deselect red and green.

A better way however is to



Install this script into Gimp

http://registry.gimp.org/node/623



Using these details

http://www.wikihow.com/Install-Scripts-Into-Gimp

Then close Gimp to reboot it and open it to load the new script.



Then scan a color image of something printed out (make sure image has 3 colors to trigger the metadots) at 600DPI (change scan settings of printer, they may not show at the default 300DPI)



load the scan into Gimp, Next select

Filters. "Filters->Politics" and click ''Show yellow tracking dots''

image will apply filter and show metadots.