What is an OCR tool?
Let’s say you want to convert a physical book into a digital format. You can spend hours typing the entire book and correcting errors or use a scanner and Optical Character Recognition (OCR) software and complete the process within hours with minimal errors.
So, what is Optical Character Recognition (OCR)?
OCR is a software program that converts handwritten, typed or printed text and images into machine-encoded text. The source of conversion can be a photo, text within a photo, scanned document or any text superimposed on an image. OCR, is thus, a method to digitize printed text.
Digital text can be edited and displayed online and accessed by the readers based on metadata and keyword search. Besides, it can also be used in various machine processes such as machine translation, text-to-speech conversion, cognitive computing, and key data and text mining. Some other use cases of OCR technology are data entry automation, indexing documents for search engines, automatic number plate recognition, and assisting blind and visually impaired people. OCR has proved immensely useful in digitizing historic newspapers and texts and a complete library of books in searchable formats.
How does OCR work?
The document to be digitized is first scanned using a digital camera or scanner. The OCR tool then comes into play. It analyzes the structure of the document image and divides the text into smaller elements such as text blocks, images and tables. The software then singles out the individual characters and analyzes different ways to break lines into words and then into characters. After processing the data, it puts characters into words, words into sentences, thus enabling you to access recognized text. Some OCR dictionaries also support multiple languages, resulting in more accurate analysis of words and documents, and consequently, more verified recognition results.
Uses of OCR technology
Apart from digitizing text, OCR technology is widely used for:
- Data entry, for example, invoices, bank statements, checks etc.
- Passport recognition at airports
- Information extraction in various businesses, for example, insurance documents and business card information
- Traffic sign recognition
- Book scanning
- Making electronic images of printed documents searchable
- Pen computing
- Assistive technology for blind and visually impaired users
- Making scanned documents searchable by converting them to searchable PDFs
The role of OCR converters in digital publishing
Digitizing print documents: OCR converts print documents into digitized documents that are editable and searchable. For optimum results, you need to improve the print quality of the document. Issues such as folds, dirty marks, coffee stains and ink blots can make a huge difference to the quality of the final output. The OCR tool can improve the print quality by photocopying the print document. Photocopying increases the contrast between the print and page, resulting in accurate character and word recognition.
Scanning: In the next step, the printout is run through the optical scanner. Sheet-fed scanners are better than flatbed scanners for OCR because they scan pages one after the other. Most OCR tools scan each page, recognize the words and characters on it and then move to the next page.
Two-color scans: The OCR tool generates black-and-white versions of the color or grayscale scanned page. If the scanned document is accurate, the OCR tool will recognize the black color as a character and white as the background. Converting the image into black and white is therefore the first stage of digitizing documents as it helps to identify what text needs to be processed.
OCR: All OCR tools generally work on the same principle, that is, they process the image by recognizing each character and then present the output word by word, and line by line in the form of recognized text.
Basic error correction: Some OCR tools have in-built spell checkers that scan for errors when a page is processed. The spell check highlights misspelled words indicating any misrecognition, allowing you to make corrections side by side. The more sophisticated tools can also conduct what is known as near-neighbor analysis. Basically, the feature can find words that are more likely to occur together, for instance, a baking bog will be automatically corrected to a barking dog given that these words are near neighbors and more likely to occur together. You can, if you wish, switch off the feature because sometimes automatic corrections could lead to an error.
Layout analysis: An OCR tool can also detect a complex page layout, for example, a print document with multiple images and tables. The tool will automatically convert images into graphics and split tables correctly, such that text from the first line of the first column doesn’t continue to the text on the first line of the second column.
Proofreading: While the OCR tool can do basic editing and proofreading, the best practice would be to have someone manually edit the document for errors.
There are several types of OCR tools available in the market, and almost all of them convert image-based documents to PDFs, .docx, or other formats. However, each OCR tool differs based on character recognition accuracy, user interface, page layout, text language, speed, and support for searchable PDF output. The basic function of OCR tools remains the same, that is, the tool will print the document, scan it, read text to two colors, detect the layout and do a simple proof check, though human editing and proofreading of the print ready output is always advisable.
While OCR is widely used in digital publishing it also finds use in various other functions. For instance, OCR is widely used in marketing campaigns. Brands use OCR to run innovative campaigns to drive engagement with their customers, for example, voucher codes which customers can redeem by typing them in the apps or websites. It is also important to mention here that there are different OCR tools that are dedicated to specialized functions, for instance, an OCR that is specially designed for payment processes in banks, or those for recognizing passports at airports. As a publisher, it is therefore important to ensure that you work with providers who specialize in OCR tools for digital publishing.
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