Theoretically you can. At least that was my orginal intent for the image tool. We still need to add some more image tools to make it easier to do so. The main one having an easy way to scale the image to real size, and locate some point on the pattern to the Basepoint, so that you cann then use other tools to trace over the image.
What I would do is on an orginal paper pattern piece is take some point and draw a square of know size as using the point as one of the corners, take a picture of it. Then in Seamly starting at the Basepoint create a square of that same kown size. Now you can load the image in, and move and resize the image so the square on the image matches the square in Seamly. Then you can trace over it.
Read this topic… this is eactly what i did with a shift dress pattern that an employee of mine draped on a dress form of a nown size.