[TIKA-3258] Run OCR on PDFs with 'auto' mode as default in Tika 2.0.0

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Assignee: Tim Allison
• Reporter: Tim Allison
• Created: 04/Jan/21 14:53
• Updated: 08/Apr/21 12:57
• Resolved: 13/Jan/21 21:07

Description

In Tika 1.x we currently have the fiddly mess that users have to configure OCR of PDFs...it doesn't just work out of the box. We did this initially because of concerns (well, reality) of crazy resource consumption for some PDFs that can have thousands of images per page that are stitched together to make a reasonable composite.

Since then, we've added option 2, which renders each page and then runs OCR on that composite image rather than running OCR on each inline image...so we'll only call tesseract once per page. Second, we've added an 'auto' mode that runs OCR only on pages that didn't have much text extracted. While there is plenty of room for improvement in the 'auto' heuristic, I think we should move to running OCR automatically on PDFs as default in 2.0.0.

Under this proposal, users will now have to disable OCR if they have tesseract installed but don't want to run it on PDFs.

This will be a breaking change, and we'll make sure to document it early and often in the "Breaking Changes" sections of the readme.txt.

Issue Links

• is related to: TIKA-2749 OCR on PDFs should "just work" out of the box