Compound Document Comparison

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Compound documents are documents that have OLE objects embedded in addition to native text or tables. Examples include MS WORD or PowerPoint documents with embedded Excel, Visio, ChemDraw, SmartDraw, Jpegs, TIFF, PNG, BMP etc.

Since many documents contain OLE objects, the need to compare the entire document, including OLE objects, is of critical importance to mitigate the risks of undetected and unapproved changes. Software-based compound document comparison compares the entire document granularly, including the native format, in addition to embedded objects like spreadsheets and images, and creates a third document highlighting modifications through a coded system. Normally this coded system takes the form of color-coding or highlighting the changes granularly. Compound document comparison can be used on any document format including Word, WordPerfect, spreadsheets, PDFs, and PowerPoint. The patent for software-based compound document comparison is held by Litéra Technology LLC.[1]


Software-based compound document comparison first separates and compares the native format in two documents. Second, compound document comparison compares all embedded objects by first marking their original place, and then comparing the objects granularly in their native form. As an example, this may include comparison on a cell by cell basis for Excel objects and pixel by pixel basis for image objects. Once the changes are highlighted on the embedded object, it is placed back into the document using the aforementioned markers.


Greater accuracy is achieved when changes to both text and embedded objects are compared on a pixel by pixel basis with software-based compound document comparison tools. Risks associated with manual user review of changes in embedded objects are eliminated using software-based compound document comparison tools.

Manual review of embedded objects such as Excel tables in a complex word processing document is not only tedious but also a potential drain on productivity. As an example, an embedded Excel sheet may take 30 minutes to manually detect all the changes while software based comparison may take seconds.

  1. ^ Massand, Deepak, Assignee Litéra Technology LLC, McLeansville, NC. 2006. Method of compound document comparison. U.S. Patent 7,818,660, filed January 2006, and issued October 19, 2010.