Optical Character Recognition

OpenCV can be used to recognize text in images, which can be useful for applications like document scanning and license plate recognition.

Updated March 24, 2023


Hey! If you love Computer Vision and AI, let's connect on Twitter or LinkedIn. I talk about this stuff all the time!

Optical Character Recognition (OCR) is a technology that enables the recognition and conversion of printed or handwritten text into machine-readable form. This has revolutionized the way we work with text in the real world, as OCR allows us to automate the process of reading, sorting, and processing textual information. OpenCV, a popular computer vision library, has played a significant role in advancing the state-of-the-art of OCR, making it more accessible and easier to use than ever before.

In this article, we’ll explore the basics of OCR, its general theory, and how OpenCV can be used to bring text to life.

What is OCR?

OCR is a technology that enables the recognition of text characters from an image or document. It works by analyzing the patterns and shapes of the characters and then converting them into a machine-readable format. OCR can be applied to a wide variety of text-based documents, including newspapers, books, receipts, and invoices, among others. It has been widely used in many industries, including banking, insurance, healthcare, and education, among others.

The general theory behind OCR

OCR is based on the principles of computer vision, machine learning, and natural language processing. The process of OCR involves three main stages:

  • Preprocessing: In this stage, the text image is preprocessed to improve its quality, enhance its contrast, and reduce noise. This makes it easier for the OCR algorithm to detect and recognize the text.

  • Text Detection: In this stage, the OCR algorithm identifies the regions of interest in the image that contain text. This is done by analyzing the shapes and patterns of the pixels in the image.

  • Text Recognition: In this stage, the OCR algorithm recognizes the characters in the text regions and converts them into machine-readable form. This is done using a combination of pattern recognition and machine learning techniques.

How OpenCV is used in OCR

OpenCV is a powerful computer vision library that provides a wide range of tools and functions for image processing and analysis. It has played a significant role in advancing the state-of-the-art of OCR, making it more accessible and easier to use than ever before.

OpenCV provides a variety of image processing functions that are useful for OCR. For example, it provides functions for image binarization, edge detection, and contour detection, which are essential for detecting and segmenting text regions in an image. Additionally, OpenCV provides machine learning tools that can be used to train OCR models, making it possible to recognize a wide variety of text fonts and styles.

Real-world applications of OCR with OpenCV

OCR with OpenCV has a wide range of real-world applications. For example, it can be used in the banking industry to automate the process of reading and processing checks and invoices. It can also be used in the healthcare industry to digitize medical records and patient data. In the retail industry, OCR can be used to scan product barcodes and track inventory. The possibilities are endless, and as OCR technology continues to advance, we can expect to see it being used in even more industries and applications.

Conclusion

OCR with OpenCV has the potential to revolutionize the way we work with text in the real world. It enables us to automate the process of reading, sorting, and processing textual information, which can lead to significant gains in productivity, accuracy, and efficiency.