How to store large amounts of data on paper with QR code like tech?
An old neighbour wants to settle his affairs - create a will, detail his investments, divide his assets among the kids etc. He asked me if it was possible to create a digital copy of all the documents (will, bank, title deed, investments, online account details etc.) and store it with some QR code like technology so that he can print all of it on a single sheet of paper and hand it to his kids. I remember reading there was some other tech (open source) that could store more data then QR, but I can't seem to recall or find it online. Any suggestions? (Let's not diverge on how there are alternate better solutions like archival disks etc).
Mind if I ask to what the vision is to have it stored on a QR code on paper?
Reason I ask is because doing it that way is creates some overhead vs just printing plain text on paper. Namely that you'd have to have the format of the QR-like-tech and create and maintain an application to execute the format for whatever current operating system.
So it's creating a bunch of additional work, and I'm not sure what benefit he has in mind.
Looked into this years ago. 2D barcodes have nowhere near the data density to encode several/multi-page documents that compactly.
But I understand exactly why he wants to do this. 35mm film is commonly available and inexpensive to process. Ilford XP2 would be ideal — black and white film that uses “C41” ordinary color processing.
Set up a stand and lighting, then click away for an hour photographing the printed documents. Send it off and you’ll have a very compact archive result in a few days.
Mount the negatives in slide holders and read with a slide viewer or projector. Or scan with a flatbed or film scanner. Or send them off for 8x10 prints.
How about zipping pure text or Markdown files, splitting them into QR-code sized chunks (1.5-3KB), converting them to QR-codes and printing all those on a single paper sheet? You can choose their sizes depending on how redundant you want them to be. And restoring them is just doing the same in reverse.
I believe you can fit pretty big texts this way without delving into a rabbit-hole of some obscure formats.
Python app code for decoding that, using existing modules, should fit on a single A4 sheet too without any encoding.
>Any suggestions? (Let's not diverge on how there are alternate better solutions like archival disks etc)
Don't try to do this, not a good idea.
If he wants physical copies that take up less space, the old fashion and time proven way is microfilm. One could probably store a bunch of QR codes on it if you wanted to.
Properly stored film is probably better than paper.
I don’t think a paper sheet can store enough information because of the paper grain. You can actually store a lot of data in a qrcode printed on paper, but not many digitalised documents.
I think he should simply print his documents and give them in a folder. That is not much different than what he wants and people will actually manage to read the documents.
Has anybody done the calculation (I'm tempted to, now), if you were to take the text, create QR codes, how much text could you reasonably have on a page? The QRs do have a certain amount of redundancy, which is good. If this is calculated, then how many pages you need is easy.
Depending on how long his will is, qr codes might work. A single qr code can store up to 4296 alphanumeric characters, which is about 2.5 pages worth of single space text. This is with a 177x177 cell qr code; not sure how many of those you could reliably fit on a single sheet of paper while maintaining readability but its probably in the double digits, especially if you can print on both sides of the sheet. If you pre-compress the text data, you might be able to get a few hundred pages of text.
I made a small script to securely backup and restore some important files: https://gitlab.com/thexa4/ocrbackup
Data density isn't great though (especially with the added redundancy) but it's enough for things like a password manager file.
Couldn't you use something like Huffman encoding to compress the entire will and print it on a single sheet of paper, then the estate could use OCR to scan and reverse the compression? If you're using ASCII characters only, I assume the compression could be very high.