[Histonet] quick and dirty scale bar

[Caroline Bass]

Hey Guys,

I'm trying to finish up some figures for a paper.  One collaborator  
has given me 10X images that appear to have been taken from a  
standard digital camera.  Can anyone suggest a quick and easy way to  
add a scale bar?  Unfortunately the journal requires it and I just  
don't have it.  I have a scale bar for a 40X picture from a different  
microscope/experiment, any chance that I can use this?  I'm guessing  
it is not as simple as my 40X scale bar being 1/4 of the 10X?

Sorry, but I am clueless about this...  any suggestions would be  
appreciated.

Thanks,

Caroline