3. The method of claim 1 , wherein the word images each have corresponding word features, and wherein the method further comprises: assigning a value to each of the word features; and calculating a distance between the at least two of the word images, based on the difference between values of corresponding word features of those two word images.
3. The method of claim 1 , wherein the word images each have corresponding word features, and wherein the method further comprises: assigning a value to each of the word features; and calculating a distance between the at least two of the word images, based on the difference between values of corresponding word features of those two word images. 4. The method of claim 3 , wherein the word images each have corresponding word features, and wherein the method further comprises: assigning a value to each word feature in a first of the at least two word images and to its corresponding word feature in a second of the at least two word images; determining the distance between each word feature in the first of the at least two word images and its corresponding word feature in the second of the at least two word images, based on the values assigned to those word features; establishing, in advance, a feature weight for each of the word features; and summing together the determined distance for all of the corresponding word features, with each determined distance weighted according to the feature weight established for that word feature.