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What is OCR?

What is OCR?

What is OCR?

OCR, or optical character recognition, is a technology that enables the conversion of different types of documents, like scanned paper documents, PDF files or images captured by a camera, into editable and searchable data.

The main use of OCR software is to take a document, identify the characters within it, and then translate those image characters into machine-encoded text that can be easily edited, searched and used in digital systems.

The origins of OCR date back to the early 1950s and it was primarily used by the postal service to read addresses and sort mail automatically. In the 1970s, ray Kurzweil developed the first omni-font OCR system, which could recognize text in any normal font. Since then, OCR accuracy has improved significantly with advanced machine learning algorithms. Today, it is a standard feature integrated into many scanners and multifunction printers. The wide adoption of OCR has enabled organizations to digitize information locked away in paper documents and improve document workflows.

How Does OCR Work?

Optical character recognition (OCR) is a multi-step process that converts scanned images of text into machine-readable text data. At a high level, it involves:

Scanning and Preprocessing Images

The first step in OCR is to scan a physical document to create a digital image file. This image then goes through preprocessing to prepare it for character recognition. Common preprocessing steps include:

  • Cropping and straightening - Removing any edges and orienting the text properly.
  • De-skewing - Correcting skewed angles of the text from the scanning process.
  • Binarization - Converting the image to black and white to separate the text from the background.
  • Noise removal - Eliminating scanning artifacts or specks that could be misinterpreted as text.

These preprocessing steps help clean up the image so that the OCR engine can more easily recognize the text characters.

Character Recognition

Once the image is preprocessed, OCR software works to identify the text characters in the image. It does this through character recognition, which matches patterns in the image to alphabetic letters or numeric digits.

Modern OCR engines utilize neural networks and deep learning to identify characters with higher accuracy. The OCR engine segments the characters, extracts features like lines and curves, and compares those to models of each character to identify which one is most likely.

Contextual Analysis

In addition to recognizing individual characters, advanced OCR engines use contextual analysis to validate those characters and words in relation to the surrounding text. This provides a way to detect and correct errors.

Contextual analysis techniques include:

  • Dictionary lookups - Checking if a word matches a known dictionary definition.
  • Lexical analysis - Examining sentence structure and grammar.
  • Semantic analysis - Validating meaning and logical connections between words and phrases.

This allows the OCR engine to use the context of a sentence or document to improve the accuracy of the final output text.


After extracting the text, OCR engines use post-processing to finalize the output. Steps in post-processing include:

  • Text formatting - Applying styles and arrangement from the original document.
  • Error correction - Automatically fixing lingering errors based on databases of common mistakes.
  • Data export - Converting and exporting the final text to an editable digital format.

Post-processing ensures the highest possible accuracy while also preparing the OCR text for practical use.

The combination of these techniques allows OCR software to convert scanned documents into usable, editable, and searchable text data. The overall accuracy continues to improve as OCR technology evolves.

Types of OCR

There are a few main types of optical character recognition (OCR) technology:

Optical Character Recognition

Optical character recognition (OCR) is the conversion of typed, handwritten or printed text into machine-encoded text. It is the most common type of OCR, where the software recognizes characters and converts images into text documents that can be edited.

OCR systems are trained on thousands of sample images to recognize characters in a wide variety of fonts, sizes and styles. Advanced OCR software can recognize text in over 200 languages. The accuracy of OCR depends on the quality of the image scanned. Higher resolution scans and simpler fonts and layouts produce better accuracy.

Intelligent Character Recognition

Intelligent character recognition (ICR) is an advanced form of OCR that uses context-based recognition and artificial intelligence to increase accuracy. ICR systems apply grammar rules and natural language processing to recognize whole words and phrases, not just individual characters.

ICR improves upon standard OCR by using database lookups and pattern recognition to guess words and spellings when uncertain. This allows ICR to better handle low quality scans with ambiguous characters. The downside is ICR requires more processing power and training.

Optical Mark Recognition

Optical mark recognition (OMR) is used to read marked areas on forms and surveys. It detects presence or absence of a mark within a defined area, rather than recognizing actual characters.

OMR is commonly used to score multiple choice exams and process survey data. It works by detecting how marks fall within predefined boxes or areas on a form. Advanced OMR can detect check marks, Xs, dots, and partially filled boxes. OMR accuracy depends on using properly printed forms.

OCR Use Cases

Optical character recognition (OCR) technology is used for a variety of applications and use cases across many industries. Here are some of the most common and impactful ways that OCR is utilized:

Document Digitization

OCR enables organizations to convert paper documents and physical records into digital formats. This allows for easier searching, storage, sharing and analysis of information contained in printed materials. OCR software can scan documents and identify the text, allowing the contents to be edited, indexed and made searchable. This is extremely useful for digitizing archives, books, magazines and more.

Data Extraction

A major use case for OCR is extracting structured data from documents like forms, surveys and applications. OCR can identify text and layout to pull out relevant data fields into spreadsheets or databases. This eliminates the need for manual data entry which is time-consuming, expensive and prone to human error. OCR data extraction enables automation to collect and digitize large volumes of critical information.

Indexing and Archiving

OCR powers the indexing and archiving of scanned documents and images to make them searchable. It analyzes page contents to tag documents with relevant metadata. This allows records to be rapidly retrieved by searching keywords, titles, dates and other attributes. OCR is essential for effectively managing and utilizing large document archives and libraries.

Invoice Processing

A frequent application of OCR processing is to extract data from invoices, bills, purchase orders and other financial documents. The structured data can automatically be exported to populate accounting, ERP or other systems. This eliminates tedious manual invoice processing, saves time, reduces errors and enables faster payment cycles.

OCR Applications

Optical character recognition (OCR) technology is integrated into many common software applications and services to enable scanning and digitization of documents and images containing text. Here are some of the most popular OCR applications:

Microsoft Office

Microsoft Office apps like Word, Excel, and PowerPoint have built-in OCR capabilities. You can scan a document directly into Word to convert it into an editable Word doc. Excel can import data from scanned tables and automatically convert it into spreadsheet format.

Google Drive

Google Drive allows you to upload images and PDFs, then use OCR to detect text and make it selectable and editable. This makes it easy to extract information from documents and reuse it digitally.

Adobe Acrobat

Adobe Acrobat Pro has a powerful OCR engine that can convert scanned documents and PDFs into searchable and editable files. It can also scan paper documents directly into PDF format.

Scanner Apps

Many scanner apps for mobile devices use OCR to convert photos of documents into editable text. This allows you to quickly digitize business cards, receipts, notes, and more using just your smartphone camera. Popular scanner apps with integrated OCR include Microsoft Office Lens, Adobe Scan, CamScanner, and Scanner Pro.

OCR integration in major productivity software and scanner apps makes digitizing paper documents seamless. Converting files into searchable and editable formats allows you to reduce paper usage and improve accessibility.

OCR Benefits

OCR technology provides numerous benefits for businesses and individuals. Some of the key benefits include:

Increased productivity

  • OCR automates the conversion of scanned documents and images into searchable and editable text. This eliminates the need for manual data entry which is time-consuming and prone to errors. OCR saves time and effort, allowing users to focus on more value-add tasks.

  • OCR speeds up document processing as multiple pages can be converted at once. This results in faster data extraction leading to more efficient operations.

Better data organization

  • OCR extracts text and recreates document formatting. This enables quick and easy organization as the converted files can be searched, edited, shared and stored just like any other digital document.

  • OCR facilitates categorization and indexing of scanned files making it simpler to manage and access documents.

Improved analytics

  • The searchable text generated via OCR allows better data mining and analysis. Users can rapidly search through large volumes of documents to find specific information.

  • OCR enhances discoverability. Data patterns and trends which may be hidden in scanned files can be uncovered through search and analytics.

Reduced costs

  • OCR eliminates the need for manual data entry which is expensive and has high error rates. This directly reduces operating costs.

  • OCR makes document management more efficient. Less administrative overhead for handling, sorting and tracking scanned files ultimately lowers costs.

  • OCR enables automated document processing workflows which optimize operations and cut down expenses.

OCR Challenges

While OCR technology has improved significantly over the years, it still faces some key challenges:

Accuracy Issues

OCR is not 100% accurate, especially when dealing with poor quality scans or unusual fonts and formats. Anything under perfect conditions can cause the accuracy rate to drop.

Handwriting Recognition

Recognizing handwritten text is very difficult for OCR. Human handwriting has a lot of variation between individuals that computer software struggles to account for.

Photo OCR

OCR software has difficulty recognizing text in photos or non-scanned images. Variations in image quality, lighting, backgrounds, etc. can obscure the text and limit OCR accuracy.

Non-Standard Formats

Unusual fonts, colors, alignments, orientations, shapes and line styles often trip up OCR software, which is designed primarily around clean black text on white backgrounds. Non-standard formats can greatly reduce accuracy.

Overcoming these challenges is an active area of OCR research and development. But for now, inconsistencies in source materials remain a barrier to perfect OCR results in all situations. Users should be aware of these limitations when evaluating options.

Improving OCR Accuracy

There are several ways to improve OCR accuracy:

Scanner Quality

Higher quality scanners can greatly improve OCR accuracy. Scanners with higher optical resolution produce clearer images, reducing issues caused by blur, distortion, uneven lighting and shadows. Calibrated scanners also minimize noise and color balance problems that interfere with OCR.

Image Preprocessing

Before running OCR, images can be preprocessed to improve results. This includes cropping, rotating, removing margins, adjusting brightness/contrast, sharpening, and converting to black and white. Cleaning up images enhances text readability and removes elements that confuse OCR algorithms.

Advanced Recognition Algorithms

OCR accuracy has improved significantly in recent years thanks to machine learning and neural networks. Advanced algorithms better handle challenging fonts, formats, languages, and noisy images. Some leverage contextual analysis to recognize entire words and phrases instead of individual characters.


As a final step, manual proofreading catches remaining OCR errors. Human review improves accuracy while also confirming proper font/format rendering. For large volumes of text, automated spellchecking can flag likely errors for human verification.

The Future of OCR

OCR technology continues to advance rapidly, opening up new possibilities in many areas. Some key trends shaping the future of OCR include:

Cloud-based OCR

Cloud-based OCR is becoming more popular as it enables easy deployment without any extra hardware or software requirements. Users can simply upload documents to process through the cloud. This makes OCR more accessible and cost-effective. Cloud OCR also allows for easy scalability to handle large volumes of documents.

AI and Machine Learning

Artificial intelligence and machine learning are being applied to significantly improve OCR accuracy. Advanced neural networks can better recognize text styles, fonts, languages, and specialized vocabularies. Contextual learning also helps correctly identify ambiguous characters. Over time, AI-powered OCR will become even more accurate.

Handwriting Recognition

Recognizing handwriting remains an OCR challenge. But machine learning is improving handwriting recognition, including varied styles and languages. Extraction of handwritten information will enable new use cases for archival documents, healthcare records, and more.

Real-time OCR

Real-time OCR enables instant text extraction from live video feeds. This has applications like instant text translation for video calls or live events. For impaired users, real-time OCR could be integrated with screen reader apps or voice assistants to quickly interpret surrounding text. Real-time OCR unlocks innovative assistive technology applications.

So in summary, OCR will continue advancing through cloud computing, AI, handwriting recognition improvements, and real-time capabilities. This will open up new ways for both individuals and organizations to efficiently digitize, search, and leverage vast amounts of unstructured text information.


Optical character recognition (OCR) technology has come a long way and made business operations more efficient. To summarize, OCR is the process of electronically recognizing printed or handwritten text from scanned documents and converting it into machine-readable text data.

OCR software works by analyzing text pixel by pixel, recognizing shapes and patterns to identify letters and words. There are several types of OCR including handwriting recognition, invoice recognition, and passport recognition that are customized to interpret different text types.

Key benefits of OCR include automating data entry, enabling full-text search, improving analytics with structured data, and digitizing paper archives. While accuracy levels are generally high, OCR still faces challenges with complex documents, special fonts and characters, poor image quality, and interpreting context.

Going forward, OCR will continue growing in importance as businesses digitize their operations. With advancements in AI and machine learning, OCR accuracy will improve further. Overall, OCR delivers immense time and cost savings by eliminating tedious manual data entry. It helps organizations effectively leverage their document data.

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