Using Tesseract OCR library

As Tesseract OCR is already integrated with OpenCV 3.0, it still worth studying its API since it allows a finer-grained control over Tesseract parameters. The integration will be studied in the next chapter.

Creating a OCR function

We'll change the previous example to work with Tesseract. We will start with adding baseapi and fstream tesseracts to the list:

#include <opencv2/opencv.hpp>
#include <tesseract/baseapi.h>

#include <vector>
#include <fstream>

Then, we'll create a global TessBaseAPI object that represents our Tesseract OCR engine:

tesseract::TessBaseAPI ocr;

Tip

The ocr engine is completely self-contained. If you want to create multithreaded OCR software, just add a different TessBaseAPI object to each thread, and the execution will be fairly thread-safe. You just need to guarantee that file writing is not done over the same file; otherwise, you'll need to guarantee safety for this operation.

Next, we will create a function...