How to use Tesseract in a multi-threaded environment?

[helong jin]

Hello everyone,

I'm currently trying to use Tesseract for text recognition in a multi-threaded application, but I've run into some issues. My goal is to capture screen screenshots in different threads and perform OCR immediately upon detecting changes in the screen. However, I've noticed that using Tesseract in a multi-threaded environment often leads to exceptions or crashes.

Here's a basic outline of my approach: I have a monitoring thread that periodically captures screen screenshots, and when changes are detected, a new thread is started to perform OCR. However, I frequently encounter problems when releasing Tesseract resources, especially when calling the End() function.

Here are some solutions I've tried:

1. Using mutexes or semaphores: I ensure that only one thread can access the Tesseract instance during OCR. While this reduces the frequency of crashes, it hasn't completely solved the problem.

2. Controlling the lifecycle of resources: I've tried releasing Tesseract resources immediately after each use, but this hasn't solved all the issues in practice.

3. Consulting official documentation and examples: I've reviewed the official Tesseract documentation and some example code, but I haven't found specific recommendations or best practices for multi-threaded applications.

I'm wondering if there are any suggestions or best practices for safely using Tesseract in a multi-threaded environment? Perhaps there are specific configurations or techniques that can help me avoid these issues.

Thank you!