1. A method for processing a batch of document images, the method comprising: processing, by a computing device, the document images into one or more documents, wherein a document of the one or more documents includes multiple pages; maintaining, by the computing device, a page-based coordinate system to specify a location of structures within individual pages of the document; combining, by the computing device, the multiple pages to form a multi-page sheet, wherein a sheet-based coordinate system specifies a location of structures within the multi-page sheet; and performing, by the computing device, a data extraction operation to extract data from the document, said data extraction operation including: detecting the structures on individual pages using the page-based coordinate system; defining a repeating group of fields, wherein the repeating group of fields is capable of flowing over from one page onto another page; detecting whether all fields of an instance of the repeating group of fields are found on consecutive pages; and depending on whether all fields of the instance of the repeating group of fields are found on consecutive pages, detecting structures using the sheet-based coordinate system, detecting structures within the document using the sheet-based coordinate system.