1. An image processing system that determines an orientation for a text-containing region of an image, the image processing system comprising: one or more processors; one or more electronic memories; one or more mass-storage devices; an orientation-marker pattern set stored in one or more of the one or more electronic data storage devices, wherein the orientation-marker pattern set comprises two or more patterns corresponding to two or more considered orientations of one or more orientation-marker characters; and computer instructions stored in the one or more electronic data storage devices that control the image processing system to receive an image with a text-containing region, store a representation of the text-containing region in one or more of the one or more electronic memories, identify one or more text-character images within the text-containing region that match an orientation-marker pattern from the orientation-marker pattern set, and 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.
1. An image processing system that determines an orientation for a text-containing region of an image, the image processing system comprising: one or more processors; one or more electronic memories; one or more mass-storage devices; an orientation-marker pattern set stored in one or more of the one or more electronic data storage devices, wherein the orientation-marker pattern set comprises two or more patterns corresponding to two or more considered orientations of one or more orientation-marker characters; and computer instructions stored in the one or more electronic data storage devices that control the image processing system to receive an image with a text-containing region, store a representation of the text-containing region in one or more of the one or more electronic memories, identify one or more text-character images within the text-containing region that match an orientation-marker pattern from the orientation-marker pattern set, and 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. 6. The image processing system of claim 1 wherein identifying the one or more text-character images within the text-containing region that match the orientation-marker pattern from the orientation-marker pattern set further comprises: for a second number of text-character images within the text-containing region, computing a number j of metric values for j different metrics with respect to the text-character image; for one or more orientation-marker patterns of the orientation-marker pattern set, determining a match score with respect to the text-character image, and when the determined match score is less than a threshold value and when the match score is smaller than the smallest match score previously determined with respect to the text-character image, storing the match score as the smallest match score and a reference to the orientation-marker pattern as the best matching pattern.