Offline use of PAGE → ALTO conversion

[mikegerber]

Currently converting from PAGE to ALTO - so one of the primary use cases for me - requires a working network connection and possibly a working HTTP proxy configuration to - apparently - load the ALTO schema. (#29) I also noticed that this conversion also needs to load - at least - xlink.xsd from the network.

There is code in PrimaDla.jar to load from a schema folder (searchForAdditionalSchemas), we should probably explore this first with the aim to pre-install all schemas in such a folder.

[mikegerber]

I think that code is only used in the unit tests, so we will have to patch prima-page-converter

[mikegerber]

Personally, I'm not super happy about relying on prima-page-converter for this. It's hard to work with (though that may be largely due to my lack of Java expertise...), hard to build (PRImA-Research-Lab/prima-core-libs#10) and one of the dependencies is closed source (PRImA-Research-Lab/prima-page-converter#17).

Did someone explore the option of doing this conversion by other means, i.e. reimplementing it in Python?

[kba]

Did someone explore the option of doing this conversion by other means, i.e. reimplementing it in Python?

Yes, I am going to invest a bit of time into this, since we need that conversion in many places and it must be fast and robust. I was going to first consider XSLT and if that turned out to be too cumbersome or inefficient, do the conversion in Python.

[mikegerber]

In addition to @kba's efforts at https://github.com/kba/page-to-alto, I also stumbled upon these XSLT files: https://gitlab.com/readcoop/transkribus/TranskribusCore/-/tree/master/src/main/resources/xslt

[mikegerber]

In addition to @kba's efforts at https://github.com/kba/page-to-alto, I also stumbled upon these XSLT files: https://gitlab.com/readcoop/transkribus/TranskribusCore/-/tree/master/src/main/resources/xslt

At least PageToAlto.xsl does not contain any mention of ReadingOrder so I think it might me unsuitable.

[bertsky]

@mikegerber, did the Pythonic page-to-alto backend solve this for you?

[mikegerber]

@mikegerber, did the Pythonic page-to-alto backend solve this for you?

Yes!