Show HN: Make PDFs look scanned (CLI or in the browser via WASM)
github.comI 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.
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
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.
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.
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...
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.
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.
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.
Sometimes companies demand you print/sign/scan a document.
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.
How is it fraud? Who is being defrauded? What is the impact to the victim?
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.
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.
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.
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.
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”.
iOS will natively let you select the text, as it does ocr on ever image. Maybe Android does the same.
MacOS does this as well in Preview.
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.
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.
This is fraud. Your are passing off a document as authentic by misleading use of visual artifacts to make the origin of the document appear different than reality.
Just because you don’t like the security theatre does make it acceptable to misrepresent the origin of a document to satisfy the security requirements.
And I gave a specific example, slipping a page into a document that wasn’t in the original and making it look like it belongs by making it look scanned.
Imagine I changed the purchase price on your home to 10% of its value rather than the original agreed price and took it to court to enforce the purchase. This tech would make that appear more credible.
You could just as easily edit it, print it, then scan it again. This tech doesn't enable you to do anything you couldn't already do.
The real problem is that written signatures are a poor form of authentication.
Just because there is an alternative path doesn’t mean this path won’t equally facilitate fraudulent acts.
That is an example of a flawed argument named false equivalence. And it ignores that the this library eliminates the friction of printing, and enables the ability to scale the process.
Everyone is overlooking the reality that multiple parties have a copy of the documents, and a judge is not going to believe that the seller agreed to 10% of market value when they claim otherwise and they have a document backing it up and so does their lawyer and so does their real estate agent. And you are going to be charged with a crime if you attempt something like this.
There are plenty of examples of a single set of documents with no corroborating documents. In fact, when I was a lawyer for Lehman in 2008 most mortgage transfers were a line in a spreadsheet not a legal document. Many wills have only a single copy that was kept in a safe deposit box. I could go on and on.
The fact remains that altering a photocopied or faxed copy of a document has been trivially easy for decades and yet it's not really a problem in real life, because it's a criminal act to do so and present it as authentic.
Which is easier to do this 10,000 times a print and scan work flow or a python script that calls this library :).
I own home care agencies in 13 states and in the early years had to collect timesheets with physical signatures for medical billing. I know the work involved in printing, collecting, scanning, organizing and retaining/archiving physical signatures at scale. We lost real money when signatures weren’t collected or were lost because there were times we couldn’t collect a replacement for various reasons.
I then built the digital system to collect signatures and had to get legislation passed to make them legally valid. We were literally blocked for several years because digital signatures were not permitted. So this isn’t a hypothetical I am throwing out just to make an argument and be annoying.
In the 2020s, outside the office (and certainly outside middle-class America), ordinary people hardly even use computers let alone printers. I have not owned a printer in 15 years. So, yes, it is a massive inconvenience. Not to mention insecure: to make a paper document I would need to share the supposedly private file with third parties.
An interesting take that reveals differing moral bases.
As a preamble, I have zero moral qualms about technically committing fraud in order to access my own money (almost nobody would).
More important, I choose not to respect a law that upholds an insecure and broken system. A parallel with traffic regulations come to mind: as a cyclist I regularly break rules when I consider that they do not best serve my safety. All things being equal, I follow the law. But all things are not always equal and bad laws are there for the breaking.
The correct outcome here is that the law is tested and amended. That is the way to end the perverse situation of the precise example you raise, where anybody with technical skills can fake a document and then win in court.
I never said that the act of making a digital doc look like it was scanned is fraud.
I said that process would be used in other fraudulent acts.
>I never said that the act of making a digital doc look like it was scanned is fraud.
Yes you did. Verbatim.
You’re dropping the important clause: to pass a document off as being of a different origin and nature specifically to make have a desired legal effect.
I think a library like this could be used for art or literature. For example, to make a document look like an old artifact in lord of the rings or a Sherlock Holmes mystery.
The fraud isn’t in the conversion or appearance. It’s in the intent behind it and how it’s used.
Hard disagree. Just because you don’t understand the rationale of a law doesn’t mean it is arbitrary and disconnected from your safety or best interest.
I’ll give a concrete example. In law school I was hired to write a memo on a traffic circle. There was a very deliberate and effective approach to identifying where pedestrian crossings were the safest. And the cross walk itself is an attempt to encourage people to go to the safe areas for crossing.
Cross walks also create a clear zone of liability. If a driver hits a pedestrian in a crosswalk they are deemed at fault. Outside the crosswalk the pedestrian is deemed to have contributed. So the law incentivizes both driver and pedestrian behavior to converge on a known safety pattern in the safer section of the road. So you can jaywalk based on your analysis that it isn’t really that big of a deal or necessary for your safety but at the scale of society the law encourages the safest behavior.
As far as signatures. I would agree there are better systems. But they still serve a valid function.
I had ATT forge mysignature on a contract to try to get me to have to pay an early termination fee. But because I had other documents with my signature I was able to demonstrate that the forgery wasn’t even close to mine. I would honestly rather have that rather than a digital stamp or Docusign.
You went to law school and you don't see any the difference between forging someone else's signature on a document and encoding one's own authentic signature into a digital document file in the manner needed by the recipient?
I do see a difference. I have said clearly there is a difference. You don’t see that the act of misrepresenting the origin and nature of a signature is deliberate deception?
I’ll give a more concrete example. If you bill the government for Medicaid home health services they required an ink signature. And in fact it had to be black ink, no other color was acceptable. When I was building software for electronic visit verification it was actually a formal legal block and required several states passing law to make digital signature images legally acceptable. If I had used a library like this to make the document digital signature look like they had been analog at some point it would have been a crime.
So just because you think it’s reasonable doesn’t mean the act of misrepresenting the origin and nature of the signature isn’t illegal.
It's just that such cases come down to technical advice that applies to a specific legal environment (certain states you mention), whereas I'm personally more interested in looking at such situations from the ethics, identity, and authenticity perspectives.
That’s fine. I studied philosophy in undergrad and happy to debate those perspectives but I was making a legal argument.
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. :)
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.
What were they expecting? A letter sent by mail?
Bunch of places want it to "look like" you've printed the page, then signed it, then scanned it. If it doesn't "look like" that, they won't accept it. Makes no sense, but I've also encountered it a bunch of times myself too.
That's right. This requirement makes a little sense if you don't actually know the signer and could conceivably end up in court with a forensic handwriting analyst testifying whether the signature was a forgery. Anything involving notarization, for example, should pass that analysis.
But for the other 99.99% of signatures in the world, any mark at all is fine, and insisting on more is wasteful bureaucracy.
They're called "wet signatures"
"However, many jurisdictions still require a wet signature. For instance, in the US and Canada, notarized documents require signatures in wet ink. Similarly, documents in areas such as family law, wills, trusts, or banking also require physical signatures. In the UK, tax authorities require a wet signature for any tax documents filed by a British resident."
https://www.adobe.com/acrobat/business/resources/wet-signatu...
I think they compared the first signature to the second and saw that they were too similar. They wanted the sequence 1. Download PDF 2. Print PDF, 3. Find pen, 4. Use pen to scribble name on paper, 5. Scan paper to PDF, 6. Upload PDF.
Without diving into too much minutiae, a legal signature can be any mark the signer intends to act as a signature. It could be a bird you've trained to poo on command onto signature lines.
In my case, this instance with Schwab was the first of a lot of similar paperwork I was going to have to do, so I pulled the ripcord when I saw how they were going to approach it.
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.
Everything can be adjusted, that mostly comes from `--paper-tone` being set too high.
Is there any good tool that does the opposite — turning scanned documents into clean PDFs? I’ve had that need recently.
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.
This has been working for me
https://lookscanned.io/en/scan
Which shares your personal data with over 200 “partners”… thanks, but no
But… does it look scanned? https://i.imgur.com/ENKZV7s.png
You can play around with the sliders to obtain results that look more dramatic: https://cleanshot.com/share/gpfyJyJV
Much better than your current demo image! The default vignette is too obviously digital
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.
It's pretty good, but there seem to be some similar products on the market that can convert locally without uploading.
This needs a flag to insert random blank pages
or make a random page the wrong orientation
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?
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.
check out ilovepdf (https://www.ilovepdf.com/) not OSS (?) but it's free
Do you have to upload your documents to their server?
ooh yeah you have to, forgot about that
cool idea, looks sooo realistic
Useful tool
Niceee
Great idea