[TIKA-3969] Inconsistent behavior on EPUB text extraction between tika-server and tika-app

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 2.6.0
• Component/s: tika-app, tika-server

Environment

I’m using a smart toaster PC running Linux Mint 20.1 (Ulyssa), MATE edition.

• Assignee: Unassigned
• Reporter: Johan van der Knijff
• Created: 08/Feb/23 19:40
• Updated: 09/Feb/23 15:37

Description

While doing some tests with Tika for text extraction from EPUB, I ran into what looks like an inconsistency between the behavior of Tika-app and Tika-server.

I’m using below EPUB file as an example:

https://www.dbnl.org/tekst/berk011veel01_01/ebook/berk011veel01_01.epub

Using the tika-app JAR, I can extract the text from this EPUB using this command:

java -jar ~/tika/tika-app-2.6.0.jar -t berk011veel01_01.epub > berk011veel01_01_tika-app.txt

Output in this case is as expected.

So then I tried this using the server. After firing up the server I use this:

curl -T berk011veel01_01.epub http://localhost:9998/tika --header "Accept: text/plain" > berk011veel01_01-tika-server.txt

In this case, Tika’s output contains elements (between square brackets) with alt-text descriptions of images. For example (from the first page of this book):

 

[image: cover]
Aster Berkhof
Veel geluk, professor!
[image: DBNL]
Colofon

 

These image references + alt-text description don't appear in the tika-app output! Not sure if this is the intended behavior, or perhaps I’m doing something wrong myself, or I’m missing some obvious option?

See also this related Tika-python issue (I initially thought this was a Tika-python problem, which on closer inspection it isn't):

https://github.com/chrismattmann/tika-python/issues/389