54. The system of claim 53 wherein: the subsets module determines the initial subset of rows for each column having more than one character block aligned in that column in the text rows of the at least one document image; and in the division module: each final subset of rows comprises at least one of the one or more text rows of the corresponding initial subset of rows having a corresponding physical structure that is most similar to the corresponding optimum set when compared to physical structures of all of the one or more text rows of the corresponding initial subset of rows; each confidence factor measures a similarity of corresponding physical structures of the at least one of the one or more text rows in one corresponding final subset of rows to each other; and each particular text row has at least one confidence factor corresponding to at least one final subset of rows in which the particular text row is an element.
53. A non-transitory computer-readable medium encoded with a system to process at least one document image comprising a plurality of text rows and a plurality of characters, each text row having at least one character, the system comprising a plurality of modules to execute on at least one processor, the modules comprising: a character block creator to create character blocks for the characters in the text rows and to determine positions of alignments of the character blocks; and a classification system comprising: a subsets module to determine columns for the alignments of the character blocks at the positions of the alignments, each text row having a physical structure defined by the columns of the alignments of the character blocks in that text row, and to determine an initial subset of rows for each column, each initial subset of rows comprising one or more of the text rows of the at least one document image having at least one alignment of at least one character block in a selected column, each initial subset of rows having a set of columns comprising the selected column and other columns in the one or more text rows of a corresponding initial subset of rows in which the selected column is present; an optimum set module to determine an optimum set of columns for each initial subset of rows by: generating a histogram of column frequencies of the set of columns in the corresponding initial subset of rows, each column frequency comprising a number of times a particular column occurs in the corresponding initial subset of rows; determining a threshold of the column frequencies for the corresponding initial subset of rows; and selecting particular columns having the column frequency above the threshold to be included in a corresponding optimum set; a division module to: determine a final subset of rows for each initial subset of rows, each final subset of rows comprising at least one text row of the corresponding initial subset of rows having physical structures most similar to the corresponding optimum set when compared to physical structures of all text rows in the corresponding initial subset of rows; determine a confidence factor for each final subset of rows; and determine a best confidence factor for each particular text row in the at least one document image; and a classifier module to create at least one class of text rows, the at least one class comprising at least one particular text row having a same best confidence factor.