A portable thermal printer includes a housing and an anti-skew unit. A semiconductor device represented by an organic field-effect light-emitting element and a method of manufacturing the same are provided. The first and second light emitting devices are positioned on the backplane in contiguous relation without a hermetic edge seal therebetween to maximize the filling factor, and an encapsulating material is received over and seals the first and second light emitting devices. The second candidate document region-of-interest mask may be refined, to form a final document region-of-interest mask, based on text features calculated from the luminance-only input image.