Are index fileds really necessary when you have the full text OCR?

Full text OCR

Ah, the old debate, do I just perform optical character recognition on all my scanned documents, make them searchable OCR PDFs, and rely on the OCR to retrieve documents?  Why use index fields when I already have all the converted text?

Index fields, or performing the indexing process, provides structured data about the documents.  This data can be utilized, especially when using document capture software, to link into columns and index fields in your document management system.  Index fields provide faster retrieval, especially if you want to be able to retrieve through specifying several criteria.  Relying on OCR, or the recognized text can get you in trouble.  First of all, you are assuming that the document will alwyas have recognized text, and that all the items that you are searching for are in the text.  Secondly, depdning on the type of OCR format you have, you may have to just find the document, and then open and parse what you are looking for.  This can also lead to false positives in retrieval if many documents have the same terms in their OCR text.

How fast is OCR Software? OCR Performance Testing

OCR Performance Testing

So which Desktop Optical Character Recognition Software is the fastest? Has the best overall performance when converting images to Word? When converting images to PDF?




I ran some testing with 4 basic desktop OCR applications to see which would have the fastest conversion times. The OCR applications are:



-eCopy Desktop (Uses the ReadIRIS OCR Engine)

-Adobe 8

-Paperport 11

-OmniPage 15



I ran all the tests on a 9 month old laptop, with a Dual Core 2 GHz processor, and 2 GB of memory. I utilized all the "out of the box" settings on the apps, with no performance tuning of settings, and I timed the speed of the applications to convert a 100 page TIFF image to Word and to Adobe Image and Text PDF.



Results of the OCR Speed Test in minutes and seconds(Word/PDF):



eCopy Desktop 4:25/2:58

Adobe 8 3:54/3:22

OmniPage 15 2:16/2:16*

PaperPort 11 2:35**



*With OmniPage you run the conversion process and then save to your preferred format.

**PaperPort just had text conversion capabilities.



I have to note that the eCopy Desktop test can be misleading in that it performs auto-orientation on all the pages before performing OCR. Also note that when evaluating an OCR application, speed is not the only factor. You need to decide up front whether you want speed, accuracy, both, or want to focus on formatting. I will write another article on formatting and which application is best in the near future.