1. A method for identifying regular geometric structures in a document page, comprising: for a document page for which a set of page elements have been identified, at least some of the elements comprising more than one line of text, providing for: identifying geometric relations among a subset of the page elements that comprise more than one line of text, from a predefined set of geometric relations; identifying a geometric structure comprising regular rows and regular columns, based on the identified geometric relations; applying constraints of a definition of a regular geometric structure to the identified geometric structure, the applied constraints being selected from the group consisting of: each page element in a regular geometric structure belongs to no more than one regular row and no more than one regular column of the regular geometric structure; each page element of a regular row of the regular geometric structure does not vertically overlap any other page elements of the regular geometric structure other than those in that regular row; and each page element of a regular column of the regular geometric structure does not horizontally overlap any other page elements of the regular geometric structure other than those in that regular column; and where the subset of page elements includes regular rows and regular columns forming a geometric structure which is determined to meet the constraints of the definition of a regular geometric structure, identifying the subset of the page elements as forming a regular geometric structure, wherein at least one of the identifying of geometric relations, the identifying of the geometric structure, and the applying constraints is performed by a computer processor.