is there a lab talk command availabel for converting an image to 'Gray and Data', as in the Origin menu? Is there also availabe a labtalk command to toggle between Data Mode and Image Mode?
Don't think so...but you can use DoMenu() to simulate it.
To get the appropriate Menu control ID just hold down SHIFT+CTRL (with the script window open) while performing the usual steps in Origin. You should see a line that looks like
Menu id=36444
Add this number to the DoMenu(36444) command and it should simulate the action if available.
One word of caution. Menu IDs can change from version to version, or even with SPs so make a note of it in your script and if ever it fails keep in mind that it's a good place to start looking for problems.