1. Open Source Ocr Software

What I've done is used a LiveCD called WatchOCR to take .PDF images of scanned documents (B&W, 300 dpi or similar) to generate searchable PDF files. This process appears to work reasonably well and appears to produce at least some recognizable text out of the images. When the PDF is viewed you can see the image but also highlight it and copy & paste the text. Using other software the PDF can be searched.

A free and open source software to merge, split, rotate and extract pages from PDF files. For Windows, Linux and Mac. An Optical Character.

The Syncfusion Essential PDF supports OCR by using the Tesseract open-source engine. How to efficiently perform OCR. You can improve the accuracy of the OCR process by choosing the correct compression method when converting scanned paper to a TIFF image and then to a PDF document. Use (zip) lossless compression for color or gray-scale images. There's tessnet2 based on great tesseract ocr engine. The Tesseract OCR engine was one of the top 3 engines in the 1995 UNLV Accuracy test. Between 1995 and 2006 it had little work done on it, but it is probably one of the most accurate open source OCR engines available. You can't extract scanned text from a PDF. You need OCR software. The good news is there are a few open source applications you can try and the OCR route will most likely be easier than using a PDF library to extract text. Check out Tesseract and GOCR. OCR Is there any open source OCR of.NET that can extract text from scanned pdf even if the text is in different fonts and it gives the ability to render it in html (or xml or text)format. Posted 14-Jun-12 5:28am elidrissi.amine1.

However my issue is that when I upload these PDF files into OpenKM these PDF files are not indexed. PDF files composed of text e.g. from Word files are indexed no problems.
Does anyone have a solution on how these files can be searched?

Below we show how to OCR convert PDF documents, for free.

Step 1: Select your PDF file

Files are transfered safely over an encrypted SSL connection. Documents stay private and are permanently removed after processing.

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Try Sejda Desktop. Offers same features as the web service, and the documents are converted locally.

Click Upload PDF files and choose files from your computer. Can also drag and drop files anywhere on the page.

Step 2: Select the language of your document

The OCR conversion process works best when the language is specified. This way ambiguous words are easier resolved based on the language dictionary.

Step 3: Select the output formats, searchable PDF and/or plain text

Convert your scan PDF to a searchable PDF file that contains text. Or convert your PDF to a plain text file containing just the text.

Tip: Output both a searchable PDF and the plain text file version

You'll get a searchable PDF document as a result, where the invisible text is overlayed on the original images at the correct locations.

Accuracy of the OCR process

To inspect the accuracy of the OCR process, open the PDF document, select all text (Ctrl+A) and copy & paste it into a text file.

Higher resolution documents consistently lead to better results. Don't compress your scans before running the OCR process.

Open Source Ocr Software

Unfortunately we can't guarantee 100% accuracy on the recognized text, this is a best-effort approach.