11. The method of claim 10 wherein the number of orientation-marker patterns in the orientation-marker-pattern set is less than 0.1%, 1%, or 10% of the total number of patterns used to represent text symbols.
11. The method of claim 10 wherein the number of orientation-marker patterns in the orientation-marker-pattern set is less than 0.1%, 1%, or 10% of the total number of patterns used to represent text symbols. 16. The method of claim 11 wherein determine an orientation for the text-containing region from the orientations of the one or more text-character images that match the orientation-marker pattern further comprises: selecting, as the determined orientation, an orientation most frequently associated with the orientation-marker patterns that match the text-character images.