1. A system that transforms a document image into an electronic document, the system comprising: one or more processors; one or more electronic memories; and a hierarchically organized data structure, stored in one or more of the one or more electronic memories, the hierarchically organized data structure comprising a plurality of entries corresponding to one or more natural-language entities selected from among one or more morphemes, words, or phrases encoded as sequences of standard feature symbols, wherein the plurality of entries are associated with a plurality of scores; and computer instructions, digitally encoded and stored in one or more of the one or more electronic memories and executed on the one or more processors, that: receive an image comprising text of a language; identify a subimage within the image, the subimage corresponding to one or more of words and morphemes; identify a set of character-sequences that represent candidate character-sequence representations of the subimage, wherein a character-sequence of the set is identified by traversing a path of the hierarchically organized data structure and accumulating a value for the character-sequence based on the scores on the path, wherein the value for the character-sequence in the set satisfies a predetermined threshold; use the candidate character-sequence representations of the subimage as hypotheses regarding lexical identities of the subimage; construct a portion of an electronic document corresponding to the received image of text using the hypotheses regarding the lexical identities of the subimage; and store the constructed portion of the electronic document in one or more of the one or more electronic memories.
1. A system that transforms a document image into an electronic document, the system comprising: one or more processors; one or more electronic memories; and a hierarchically organized data structure, stored in one or more of the one or more electronic memories, the hierarchically organized data structure comprising a plurality of entries corresponding to one or more natural-language entities selected from among one or more morphemes, words, or phrases encoded as sequences of standard feature symbols, wherein the plurality of entries are associated with a plurality of scores; and computer instructions, digitally encoded and stored in one or more of the one or more electronic memories and executed on the one or more processors, that: receive an image comprising text of a language; identify a subimage within the image, the subimage corresponding to one or more of words and morphemes; identify a set of character-sequences that represent candidate character-sequence representations of the subimage, wherein a character-sequence of the set is identified by traversing a path of the hierarchically organized data structure and accumulating a value for the character-sequence based on the scores on the path, wherein the value for the character-sequence in the set satisfies a predetermined threshold; use the candidate character-sequence representations of the subimage as hypotheses regarding lexical identities of the subimage; construct a portion of an electronic document corresponding to the received image of text using the hypotheses regarding the lexical identities of the subimage; and store the constructed portion of the electronic document in one or more of the one or more electronic memories. 4. The system of claim 1 wherein the computer instructions, executed on the one or more processors, identify the set of character-sequences that represent candidate character-sequence representations of the subimage by: transforming the subimage into a sequence of feature symbols with associated parameters, each feature symbol associated with no, one, two, or more than two parameters and each feature symbol with associated parameters corresponding to a text-line feature; storing the sequence of feature symbols with associated parameters in one or more of the one or more electronic memories; using the sequence of feature symbols with associated parameters to identify candidate words, candidate morphemes, or candidate words and morphemes corresponding to the subimage that are encoded as sequences of standard feature symbols within the hierarchically organized data structure; using the identified candidate words to determine and store, in one or more of the one or more electronic memories, probable inter-character division points and traversal paths for the subimage; using the probable inter-character division points and traversal paths for the subimage to generate candidate traversal paths for the subimage; and generating the set of character-sequences that represent candidate character-sequence representations of the subimage from the candidate traversal paths.