21–24 of 24 posts
If anyone sent me data in PDF format I would immediately reject it and ask for a more suitable format. This isn't because I know anything about PDF, it's just intuition. Why don't more people come with this intuition? I feel the same way about basic security principles.
OCR the PDF. It's the ground truth, and it's not like it's more complex than parsing a pdf, at this point, the technology for OCR might even be better than PDF parsing, which is full of accidental instead of natural complexity.
I don’t really understand how OCRing a PDF could be more accurate than reading the text nodes. Another thing to consider is OCR works well for English but not so well for other languages.
However in this case, we see a scenario where OCR would be more accurate indeed. So just reread the article and you might understand how OCR can be more accurate. It's because in case of disparity between the printed optical 2D matrix and some interpretation of the text/print encoding, the optical matrix is correct. PDF is a printing encoding, not a machine consumption, there's thousands of ways to print a document, it's not feasible or practical to understand all of them to build a document parser, you need to focus on the end result, not the process, like we do when analyzing a document.
If you are analyzing the Mona Lisa, maybe it's useful to understand how it was painted. But if you are analyzing your electricity bill, it's likely that going into what order the numbers were printed and what ink was used, is going to be more of a distraction than anything useful.
>Another thing to consider is OCR works well for English but not so well for other languages.
Maybe, not terribly in scope for the case in the OP, as long as arabic numerals are used, that's the core of the requirements.
Earlier quoted context omitted.
I don’t really understand how OCRing a PDF could be more accurate than reading the text nodes. Another thing to consider is OCR works well for English but not so well for other languages.
As the article stated, in this specific case the bank used an "invisible" character (a minus sign) to assist in alignment .. which resulted in errors when parsing the text nodes by layout. OCR of a digital image generated from those PDF draw commands only operates on the visible portions that are rendered. Another case to be considered .. FOI requests for documents from "pain in the arse" government departments or la…
PDF is used as DRM by obfuscation by non technical users, it's a sort of emergent phenomenon that occurs hundreds of times per day. And it turns out it's a quite effective tool at that, if anything it associates a cost to editing/copying/automatic processing.
In terms of technically compliant, a PDF is as much of a sensible requirement as USB or String types. It checks the box, but it's likely that there's a lot of additional work into integrating two systems that input and ouput these envelope protocols/encoding, because they are purposefully too broad.
If anyone sent me data in PDF format I would immediately reject it and ask for a more suitable format. This isn't because I know anything about PDF, it's just intuition. Why don't more people come with this intuition? I feel the same way about basic security principles.
The domain name of this blog post should give you a clue why OP shouldn't follow your intuition.