The seam allowance is the strip of fabric between the seam line and the cut edge. It gives the seam the room it needs, commonly 0.7 to 1.5 cm.
Whether the allowance is already in the paper pattern or gets added digitally decides which contour you photograph. PatternScan Pro can add it afterwards.

Digitize sewing patterns without tracing.
Test PatternScan Pro free for 14 days with the full feature set. You need your smartphone, a printer and one pattern you always wanted digital.