Identifying text in an image is a very popular application for Computer Vision. This process is commonly called OCR and divided into the following steps:
Text preprocessing and segmentation: During this step, the computer must learn to deal with the image noise and rotation (skewing) and identify what areas are candidate text areas.
Text identification: This is a process used to identify each letter in a text. Although this is also a Computer Vision topic, we will not show you how to do this in this book using OpenCV. Instead, we will show you how to use the Tesseract library to do this step, since it was integrated with OpenCV 3.0. If you are interested in learning how to do what Tesseract does all by yourself, take a look at Mastering OpenCV, Packt Publishing, which presents a chapter about car license plate recognition.
The preprocessing and segmentation phase can vary greatly depending on the source of the text. Let's take a look at the common...