With optical character recognition (OCR) technology, OCR software automatically extracts text from any scanned PDF or image file and OCR converts it to a searchable PDF file. With OCR software, you can transform a scanned PDF of a paper document into a text-searchable PDF document. This new OCR searchable PDF is like an image containing text data, that you will be able to search for a specific keyword. When we read a document, our brain recognizes a character by analyzing the patterns and compare them against the pre-learned alphabet set. An OCR software application is trying to do the exact same. An OCR software reads the text pixels from a scanned image and compares it against a pre-trained dataset. Once the text is recognized, it is added as a hidden layer in the scanned PDF. This new "sandwiched PDF" file is popularly known as a searchable PDF.
What are the benefits of a searchable PDF over a scanned PDF? It is easier for an end-user to search for a piece of information if you convert scanned PDF to a searchable PDF. A searchable PDF enhances the value of your scanned PDF by adding an invisible OCR text layer on top of the scanned image content. Normally it is created by an OCR converter software application. This text layer can be searched using the search button of your PDF reader software. You can copy text from a searchable PDF and paste it into another program like notepad or word. A scanned PDF is inaccessible for a disabled person because the "text" is just an image of a document. When you OCR convert a scanned PDF, it enhances the readability of the document and it can be used by applications like windows narrator. A searchable PDF helps an organization in the digital transformation of the company into a paperless office.