Multithreading in Python

In the previous post, I investigated a way to preprocess images using multiple processes. In this post, I will investigate a way to preprocess images using multiple threads.

The real difference from the multiprocessing code is not much. Instead of using multiprocessing.Pool class, use multiprocessing.pool.ThreadPool class. Below is the code:

The execution time for multithreading is a bit slower than that of multiprocessing, but I am not sure if this is always the case, as the difference is not significant.

single thread elapsed time: 364
2 threads elapsed time: 184
4 threads elapsed time: 115