Recovering redacted information from pixelated videos

Re:Recovering redacted information from pixelated videos by Syzygies on Tuesday January 25, 2022 @09:21AM (#30072047)

As University libraries have moved online, one reads many poorly scanned journal articles. I often wonder about taking the time to clean them up. What replaces temporal information here is the same characters appearing over and over.

So of course I read this article hoping to learn about an off-the-shelf tool that would do a great job of scanned text reconstruction. Alas, the best candidates were "no code available."

[ Parent | on HN ]

Re:Recovering redacted information from pixelated videos by throwawayciv651 on Tuesday January 25, 2022 @12:33PM (#30074853)

Not off the shelf but here are some tools. I have no experience with them.

Wolf binarization - I think it makes the text more clear before OCR.

https://github.com/chriswolfvision/local_adaptive_binarizati...

This thing OCRs the pdf using Tesseract OCR

https://github.com/ocrmypdf/OCRmyPDF/

Two other pdf tools

https://github.com/qpdf/qpdf

https://github.com/pikepdf/pikepdf

[ Parent | on HN ]

Re:Recovering redacted information from pixelated videos by Syzygies on Tuesday January 25, 2022 @05:13PM (#30078866)

I'll play with the Wolf filter, thanks.

Math typesetting is too messy for current OCR tools. It would be nice to reverse-engineer the LaTeX source for a math paper, but not likely soon. OCR for the language would help in mind-mapping a web connecting my saved papers, but I wouldn't use it for reading.

I want everything to look like a 600dpi scan mixed down, as I would make, rather than what the libraries thought would be acceptable. For the pure joy of reading.

The easiest approach that might work would be language agnostic, understanding only what clean scans of characters look like. Can we back-solve a clean scan from a lower resolution mess, matching up similar characters in the text without identifying the characters?

Somehow I imagine this is a giant singular value problem. I'm ok if it takes a day to run per paper, I have spare machines.

[ Parent | on HN ]

Re:Recovering redacted information from pixelated videos by throwawayciv651 on Tuesday January 25, 2022 @06:16PM (#30079503)

Found these 2 for math LaTeX OCR:

https://github.com/lukas-blecher/LaTeX-OCR

https://github.com/harvardnlp/im2markup

Also some LaTeX editors:

LyX https://en.wikipedia.org/wiki/LyX

TeXstudio https://en.wikipedia.org/wiki/TeXstudio

GNU TeXmacs https://en.wikipedia.org/wiki/GNU_TeXmacs

[ Parent | on HN ]

Re:Recovering redacted information from pixelated videos by rasz on Tuesday January 25, 2022 @11:26PM (#30081700)

I imagine you could go really far with a dumb approach or matching against pre existing font database.

[ Parent | on HN ]