1. A method of decomposing a two-dimensional structured representation of an input document using multiple one-dimensional methods, comprising: creating an input document schema tree with nodes; deriving a set of valid input paths in the two-dimensional structured representation of the input schema and a set of valid output paths in a two-dimensional structured representation of an output schema; determining a first mapping and/or re-labeling function from the input paths into the output paths, applying suitable classification rules; and determining a second mapping and/or re-labeling function from the suitable classification rules to structural actions; wherein determining a first mapping and/or re-labeling function from the input paths into the output paths, applying suitable classification rules, comprises: establishing leaf extraction rules that include one-dimensional simple path leaf delimiter candidates, associated classification labels, and associated confidence levels; storing path candidates in a candidate index wherein the candidate index is in the form of a tree data structure that stores all simple path delimiter candidates, the simple path delimiter candidates including reverse path delimiters, and the candidate index stores information sufficient to determine the most discriminative delimiters; where the candidate index allows incremental accommodation of new annotated samples; determining, for each leaf, which leaf delimiter candidate has a highest confidence level; determining a classification label for the leaf content based on the leaf delimiter candidate having the highest confidence level; and providing a classification label for each leaf with respect to which leaf delimiter has the highest confidence level to achieve a valid two-dimensional tree according to the output schema.