Continuation of an interrupted training

[amitdo]

From issue #3560:

@stweil commented,

There are other training aspects which I consider more important.

One is continuation of an interrupted training. That should start with the line following the last one which was used for training. I'm afraid that it currently starts with the first line, so a training which was interrupted is different compared to a training which runs without any interrupt.

[DesBw]

Is is about interrupted trainings as in the user hits ctrl+Z (or ctrl+c)? Or, does the issue includes all types of interruptions such as training in step wise (first round 10000 iterations, then, the next round 100000 iterations etc)?

I hope the issue affects only in cases that are explicitly interrupted by the user. If it affects the latter case as well, we should have been warned because it has been a rule of thumb to train incrementally (slowly increasing the iterations).

[stweil]

It always starts with the first training data, no matter how it terminated before. Therefore I now always use epochs instead of iterations. Other OCR software always uses epochs and also saves the intermediate models after each epoch. That's what I do when training Tesseract models, too.

So if you have a large data set for training, start with the first epoch (--max_iterations -1), save the final model, restart the training for the 2nd epoch (--max_iterations -2), save the final model again and so on.

[DesBw]

Well, I didn't know that. I have been reading different forums and people are just saying I can start from a small number of iterations and slowly increase it. This is absolutely very important information: need to be told for anyone trying to train Tesseract.

• That means, we have been repeatedly training the same lines: leaving out others. I now understand why I was getting 0% error rate before I run as many iterations as the number of texts.

Thank you clarification. I hope you guys will improve tesseract for future releases so that it will continue where it stopped from.

[DesBw]

Almost two years, no progress on this request.