THE DOCUMENT SPECTRUM FOR PAGE LAYOUT ANALYSIS

Page layout analysis is a document processing technique used to determ ine the format of a page. This paper describes the document spectrum, or docstrum, which is a method for structural page layout analysis bas ed on bottom-up, nearest-neighbor clustering of page components. The m ethod yields an accurate measure of skew, within-line, and between-lin e spacings and locates text lines and text blocks. It is advantageous over many other methods in three main ways: independence from skew ang le, independence from different text spacings, and the ability to proc ess local regions of different text orientations within the same image . Results of the method shown for several different page formats and f or randomly oriented subpages on the same image illustrate the versati lity of the method. We also discuss the differences, advantages, and d isadvantages of the docstrum with respect to other lay-out methods.