calmari/1.0: Fix 1.0.x models for Python 3.11

[mikegerber]

We have old 1.0.x models that wouldn't run using the Calamari 1.0.x branch on Python 3.11, as the replacements use regexen now considered invalid in Python 3.11:

re.error: global flags not at the start of the expression at position 3

E.g. in our 0.ckpt.json:

            {
              "old": "\\s+(?u)",
              "new": " ",
              "regex": true
            },
            {
              "old": "\\n(?u)",
              "regex": true
            },
            {
              "old": "^\\s+(?u)",
              "regex": true
            },
            {
              "old": "\\s+$(?u)",
              "regex": true
            }

The global (?u) regex flag needs to go in front. This script fixes it:
https://github.com/OCR-D/ocrd_calamari/blob/master/ocrd_calamari/fix_calamari1_model.py

The question is if you want this "upgrading" procedure to go into the 1.0 branch's modeling loading code?

(I haven't checked any other 1.0 models, but I am somewhat sure that these replacements weren't customized by us and came from Calamari itself.)

[mikegerber]

Related issue in ocrd_calamari is here: OCR-D/ocrd_calamari#91

[andbue]

Hi @mikegerber, I've just made two commits to the 1.0 branch: the first is trying to fix the regex problem and the second to make all the tests run without warning. Could you please test if this works with ocrd_calamari?

[mikegerber]

Hi @mikegerber, I've just made two commits to the 1.0 branch: the first is trying to fix the regex problem and the second to make all the tests run without warning. Could you please test if this works with ocrd_calamari?

Unfortunately this only got called for the default parameters, not the ones read from the model on disk. I've had another look and opened PR #349. That PR fixes the issue for me!

[mikegerber]

(I have 2 other issues with 1.0.x - more NumPy noise and another small issue with noise in the output. If you want to release another 1.0.x version maybe wait a little bit, I still need to investigate if it's Calamari or ocrd_calamari.)

[andbue]

Thanks a lot – I didn't have an old model so I was just guessing where to fix the regexes... If you have any other suggestions, I'll gladly include them in the 1.0.7 release!

[mikegerber]

Yeah I should have linked our historic model so you can reproduce :)

If you need a working model for 1.0 in the future: https://qurator-data.de/calamari-models/GT4HistOCR/2019-12-11T11_10+0100/model.tar.xz

(only for old prints/Fraktur)

[mikegerber]

If you have any other suggestions, I'll gladly include them in the 1.0.7 release!

I'll try to debug today!

[mikegerber]

The other issues:

• PR calamari/1.0: Remove noisy/useless print around model.summary() call #350 removes a little noise
• I get a UserWarning from NumPy 1.26.1, but it's not a problem in Calamari.

So I think you could release 1.0.7 when #350 is merged and this issue can be closed too :)

[mikegerber]

Nevermind, there's still lots of DeprecationWarnings I'd like to take a look first (other than the ones @andbue thankfully already fixed)

[bertsky]

Sorry @mikegerber – I did not see #350 when releasing 1.0.7.

I'll merge that soon. So perhaps we should do another 1.0.8 ...

More than anything else we urgently need to backport the recently added support for TF SavedModel format to all the older branches – because HDF5 models stop working across the Python 3.8 / 3.9 boundary IIRC. The main problem with that is we cannot just increase the version tag of the older models retroactively (as was done with 5→6 in master). I have discussed this with @andbue and he is inclined to implement the auto-conversion without version update there.

[bertsky]

I'll merge that soon. So perhaps we should do another 1.0.8 ...

done.

I suggest we keep this issue open to track progress with the SavedModel format conversion in 1.x (and the other older branches).

[bertsky]

I suggest we keep this issue open to track progress with the SavedModel format conversion in 1.x (and the other older branches).

Since Calamari 2.3 (or rather, the initial implementation by @andbue for SavedModel format) already includes a new model/checkpoint version 6 (rather than an unversioned optional variant), there is no chance of supporting this in 1.x – as there is no way to increase the model version with an integer between 2 (Calamari 1.x) and 3 (Calamari 2.0).

But the good news is that I made a lot of progress:

• migrating all public models in calamari_models and calamari_models_experimental to version 6, and beyond that also fixing their re quirks; each model also available separately in the GH release assets
• making Calamari 2.3 usable with recent TF versions and up to Python 3.11
• implementing a version of ocrd_calamari compatible with Calamari 2

The only problem is that I cannot migrate @mikegerber's model qurator-gt4histocr due to #362. So we are stuck with 1.x for that, where none of this is of any help.

In 2.x on the other hand, there might even be other (non-public) models out there which have the same problem – even amongst newer model versions (I did see this in calamari_models). So we could really use a re fixup for 2.x as well. Either in @andbue's method of ad-hoc replacement 13b544b or in @mikegerber's method of in-file replacement 55d6a4d. (The source file now moved to calamari_ocr/ocr/dataset/textprocessors/text_regularizer.py and changed quite a bit, but it's not hard to reproduce.)

So if we want that, we should rename this issue to cover the calamari/2.x case exclusively – otherwise close (as @mikegerber's solution has already been merged in 1.0.7).