ALTO (XML) ALTO (Analyzed Layout and Text Object) is an open XML Schema developed by the Library of Congress for OCR text and layout information. It is often used with Metadata Encoding and Transmission Standard (METS). ==Structure== An ALTO file consists of three major sections as children of the root element:〔(Structure of ALTO Files )〕 * section contains metadata about the ALTO file itself and processing information on how the file was created. * section contains the text and paragraph styles with their individual descriptions: * * has font descriptions * * has paragraph descriptions, e.g. alignment information * section contains the content information. It is subdivided into elements.