I'm not a developer, i always use this free online ocr tool to convert image to searchable pdf document(http://www.online-code.net/ocr.html).

There is a good portion of posts on the internet about performing Optical Character Recognition (OCR). There many free OCR engines that you can use like MODI, GOCR, Akshara Malayalam and Tesseract. I implement an OCR engine from leadtools in my application but I was able to do a quick search and find many samples on how to use Tesseract OCR engine. Here is the link: http://www.codeproject.com/Articles/696537/How-to-Use-Tessnet-Library And you can find more information about Tesseract here: https://code.google.com/p/tesseract-ocr/