Show HN: Make PDFs look scanned (CLI or in the browser via WASM)

https://github.com/overflowy/make-look-scanned

by overflowy • 1 month ago

155 65 1 month ago

I made this because the online "make my PDF look scanned" tools want you to upload your file to their servers, which feels sketchy at best. Also, I wasn't happy with the output they produce, I wanted something that looks realistic.

blopp99• 1 month ago

Niceee

costabrosky• 1 month ago

Useful tool

mysterydip• 1 month ago

I’m all for fun side projects, so don’t take this the wrong way. Does this have a practical use case? Like are people actually wanting to make their PDFs less legible? Usually I’m trying to do the opposite, clean up my scanned-in documents.

ktpsns• 1 month ago

This is in fact useful for people who demand you to print out and sign contracts. Did so many times in the past, using some ghostscript+imagemagick scripting to avoid the cargo culturing.

laurencerowe• 1 month ago

Sometimes companies demand you print/sign/scan a document.

pooploop64• 1 month ago

I've been in situations where I had to supply a digital version of a signed document but the person asking for it required that it be physically printed off to be signed and then scanned back in. Some policy thing. I think it would technically be fraud to use this but that's one use I thought of.

The description however seems like the creator just likes how scanned documents look. They describe it like how analogue music fans describe vinyl records. I guess everything is nostalgic to someone out there eventually.

monkpit• 1 month ago

How is it fraud? Who is being defrauded? What is the impact to the victim?

jhbadger• 1 month ago

For some value of practical, I could see it being useful in making handouts for an RPG where the handout is supposed to be a photocopy of a section of some rare book the players need to scan for clues.

nutjob2• 1 month ago

Typically when I send a form I will do as much as possible in a PDF editor, including the signature. Most of the world is in denial about how electronic documents, especially scanned ones, work, so you have to play along to stop them from getting upset.

BrandoElFollito• 1 month ago

There are countries such as France that request plenty of nonsensical handwriting with some weird also handwritten formulas. This comes from the times where graphology was a big thing in France (you would usually be required to send a handwritten letter of motivation).

Poland is also strong on that, requiring "readable handwritten signatures".

This will end when the dinosaurs that still feel it is important go away.

PufPufPuf• 1 month ago

I was actually required in the past to "print, sign and scan", and due to my lack of a printer I just took a picture of my signature and pasted it in. Nobody ever complained, but if they did, I imagine I'd rather use something like this than go to a copycenter to print a single sheet of paper to satisfy some arbitrary requirement.

gsinclair• 1 month ago

I sometimes want to create PDFs that contain text (Python code) that is not selectable. I want my students to type it in, not copy and paste.

I don’t know whether this tool enables that, but the idea is in the neighbourhood of “make it look scanned”.

carstenhag• 1 month ago

iOS will natively let you select the text, as it does ocr on ever image. Maybe Android does the same.

digitaltrees10• 1 month ago

Yes. Fraud. It makes a document look like it existed in physical form. Imagine for example a purchase agreement for a house that was physically scanned. You could change the signature to a different name and then make it look like it was original.

I am not asserting the authors intent is to facilitate fraud or there isn’t any other practical use, but let’s not be naive and act like fraud isn’t a likely use.

Before you downvote at least respond with why you think my analysis is wrong.

bluebarbet4• 1 month ago

It's not that you're wrong, but the fact that it would be fraud is farcical and needs to be challenged.

My bank demands that I perform this ridiculous hoop-jumping. Like others here, I use ImageMagick hocus pocus to defeat them with trivial ease (a couple of times they complained so I tweaked the algo a bit and they were happy). The whole situation is beyond absurd. It's security theater in place of security.

BenjiWiebe• 1 month ago

Print - sign - scan. I've never been told to keep the physical print out.

I've also never had someone refuse my too-perfect digitally inserted signature, but I could totally see it happening.

Oh and I don't like signing stuff anywhere, so I also used my scanned signature and got a custom stamp made. :)

sowbug3• 1 month ago

Charles Schwab, the brokerage, didn't like that my signed form retitling an account looked too perfect (I had scanned my signature and then inserted the JPEG into their PDF form, which is absolutely 100% legal as a signature). So I printed the form out and sent them a picture of the printout. They didn't like that, either.

So I moved my money out of the account. That worked fine.

Symbiote• 1 month ago

What were they expecting? A letter sent by mail?

echoangle• 1 month ago

If you’re interested in another suggestion: maybe allow image output too since that seems to be one of the steps in your pipeline? Maybe for some people using the jpg or a png directly is better than the final pdf.

ashton314• 1 month ago

This needs a flag to insert random blank pages

molybd3num3• 1 month ago

or make a random page the wrong orientation

wan888888• 1 month ago

I'm having a similar use case from time to time, I just use imagemagick

magick -density 150 input.pdf \ -colorspace Gray \ -virtual-pixel White -background White \ -rotate 0.7 +repage \ -attenuate 0.45 +noise Gaussian \ -blur 0x0.4 \ -brightness-contrast -5x12 \ -compress jpeg -quality 78 scanned.pdf

__mharrison__• 1 month ago

I have something similar. Someone asked for a signed PDF. I digitally signed it and sent it to them. They said it has to be scanned. So I did some image magic fu to it to rotate it and make it look crappy. Then they accepted it.

nashashmi• 1 month ago

My goto technique: apply signature stamp. Flatten. Change blend mode to multiply. Convert page to image. Rotate image by 0.5 deg. Paste scanned page on tape. Flatten. Change blend mode of image to burn or multiply. Convert to image.

The only tell tale sign is that the text still has this aliasing like texture that doesn’t happen in real scanned pages.

1a527dd5• 1 month ago

Yeah I don't want to rain on OPs parade; but this is already a solved problem:

From my bookmarks (found on HN originally!)

https://gist.github.com/andyrbell/25c8632e15d17c83a54602f6ac...

carsonye• 1 month ago

Is there any good tool that does the opposite — turning scanned documents into clean PDFs? I’ve had that need recently.

colesantiago• 1 month ago

Thank you for making this a free tool.

There are too many PDF tools that are unnecessarily paywalled, or have a paid tier that don't make any sense.

We need more tools from paid ones that should be completely free and OSS.

molybd3num3• 1 month ago

check out ilovepdf (https://www.ilovepdf.com/) not OSS (?) but it's free

normie3000• 1 month ago

Do you have to upload your documents to their server?

sublinear• 1 month ago

In the example image, the edge gradient bevels give it away.

There might be extra stuff that can be done to remedy that with this tool, but I'm not sure I'd ever use this anyway.

overflowy2• 1 month ago

Everything can be adjusted, that mostly comes from `--paper-tone` being set too high.

kccqzy• 1 month ago

I just display the PDF on my monitor and use my phone to take a photo of it. Scanner apps are good at eliminating moire patterns while accentuating the dust on my monitor. It looks highly realistic.

janoelze• 1 month ago

But… does it look scanned? https://i.imgur.com/ENKZV7s.png

overflowy2• 1 month ago

You can play around with the sliders to obtain results that look more dramatic: https://cleanshot.com/share/gpfyJyJV

sprobertson• 1 month ago

Much better than your current demo image! The default vignette is too obviously digital

Rajikshank• 1 month ago

Great idea

Cbagenal• 1 month ago

cool idea, looks sooo realistic

hk1337• 1 month ago

Basically, you’re converting it to an image-based PDF so they cannot just scrape the text off of it but would have to use OCR?

recroad• 1 month ago

This has been working for me

https://lookscanned.io/en/scan

catoc• 1 month ago

Which shares your personal data with over 200 “partners”… thanks, but no

Phoenixhq• 1 month ago

It's pretty good, but there seem to be some similar products on the market that can convert locally without uploading.

svl7• 1 month ago

Reminds me of this: https://github.com/erstazi/falsisign

Adds your signature and makes it look scanned. Previously discussed on HN. Came in handy once in a while.

Show HN: Make PDFs look scanned (CLI or in the browser via WASM)

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