How can I undo changes made to a picture I accidentally saved via preview? The was a picture that I was looking at in my computer, I drew a line with the preview tool.
Since my was slow and the app was not responsive,  I force quited Preview.
I opened the document and  it saved the line I drew on the picture as part of the picture. I don't have the original picture but I don't want the line to be there.
Can I undo what I have done via a backup or version of this file?
With Preview open:

File > Revert To > Browse All Versions 

Select the original version.