Graphical syntax analysis of tables through tree rewriting

摘要

To determine a table structure, a spatially ordered sequence of rectangular cells (42) disposed in a two dimensional region is derived. The ordered sequence of rectangular cells is parsed in accordance with a two-dimensional structural grammar (54) having terminal elements corresponding to cells and non-terminal elements corresponding to structural relationship operators. The parsing produces a grammatical expression (52) with the cells represented by terminal elements and structural relationships represented by non-terminal elements.