5 ms·
From the github repo, the site is a wrapper around exactly two shell commands. Instead of uploading your data to an untrusted site, you can run from the comfort
by jmwilson 6y ago
From the github repo, the site is a wrapper around exactly two shell commands. Instead of uploading your data to an untrusted site, you can run from the comfort and safety of your local computer:
convert -density 150 input.pdf -colorspace gray -linear-stretch 3.5%x10% -blur 0x0.5 -attenuate 0.25 +noise Gaussian -rotate 0.5 temp.pdf
gs -dSAFER -dBATCH -dNOPAUSE -dNOCACHE -sDEVICE=pdfwrite -sColorConversionStrategy=LeaveColorUnchanged dAutoFilterColorImages=true -dAutoFilterGrayImages=true -dDownsampleMonoImages=true -dDownsampleGrayImages=true -dDownsampleColorImages=true -sOutputFile=output.pdf temp.pdf
- miles 6y agopmiller2 linked[0] to some alternatives[1], including this one[2] which only requires ImageMagick: convert letter.pdf -colorspace gray \( +clone -blur 0x1 \) +swap -compose divide -composite -linear-stretch 5%x0% -rotate 1.5 as-scanned.pdf [0] https://news.ycombinator.com/item?id=23157979 https://news.ycombinator.com/item?id=23157979 [1] https://tex.stackexchange.com/questions/94523/simulate-a-scanned-paper https://tex.stackexchange.com/questions/94523/simulate-a-sca... [2] https://tex.stackexchange.com/a/94541/185219 https://tex.stackexchange.com/a/94541/185219
- baicunko 6y agoI'd recommend GS after ImageMagick as IM will hugely increase the size of the output due to rasterization!
- miles 6y agoThe above convert command produced credible output only 6KB larger than the input PDF in my limited testing.
- apetresc 6y agoBut that in itself is a tell.
- miles 6y agoThe whole purpose is to make a new PDF that looks like it was scanned. The file size differing from the original is a feature, not a bug.
- jschwartzi 6y agoAnyone unsophisticated enough to require you to print and handwrite a signature is also unsophisticated enough to not realize that the PDF size is a tell.
- baicunko 6y agoWhen I tested using only IM I was getting 3x file size. I will further test your command to see how this improves the current situation, thanks!!
- derefr 6y agoBut isn't rasterization necessary for this deception to work? Unless there's some magical scanner out there that's outputting vector images.
- eru 6y agoWhether leaving as vector works depends on how much your recipients care to investigate.
- deleted 6y ago[deleted]
- baicunko 6y agoIn summary you could say yes but I wanted to simplify the process for the not-so-techy person. I will work on a Standalone app that simplifies the command and shows a nice GUI for more private documents
- ryanwaggoner 6y agoI hope you don’t take the comment you’re responding to as anything negative. I’m a software engineer and I would use this myself rather than try and remember some arcane command line utility.
- ARandomerDude 6y agoMake it a bash script! I have all kinds of scripts for things I don't want to remember in my ~/bin.
- cerved 6y agoA software engineer!?? On HN!?? IMPOSSIBLE
- baicunko 6y agoNot at all, I'm actually quite happy with all the comments, ideas and feedback I've received on this, really encourages me to keep improving the project
- gdilla 6y agoi just tell people the dropbox app will scan docs for you. comes out looking like a photocopy. perfect for the bankers.
- cs702 6y agoTry this one-line ImageMagick command to make COMPACT pseudo-scanned files: convert -density 150 ORIGINAL.pdf -colorspace gray +noise Gaussian -rotate 0.5 -depth 2 SCANNED.pdf Consider using `-depth 1`, `-depth 3` as a final parameter to map colors to only 2¹=2 or 2³=8 instead of 2²=4 gray levels. Using a small number of gray levels SIGNIFICANTLY reduces file size and also gives your pseudo-scanned document a more pixelated, it-just-came-out-of-my-old-printer look. Also consider using `-density 100` or even `-density 75` for long text documents. Using a density of 75 dpi produces documents that are 4x smaller than 150 dpi (75²=150²/4) and doesn't affect the readability of normal-sized (10-12pt) text that much. Finally, sometimes it works best not to add Gaussian noise.
- miles 6y agoRather than making a COMPACT version, your command created a file over twice the size of one created using the aforementioned convert letter.pdf -colorspace gray \( +clone -blur 0x1 \) +swap -compose divide -composite -linear-stretch 5%x0% -rotate 1.5 as-scanned.pdf However, that may be a useful feature, since many users end up inadvertently creating very large PDFs when scanning.
- Moru 6y agoIf you lower the resolution those auto-scanning services that does OCR on the documents will get problems converting the tex back to normal text. Which might or might not be the point of doing this in the first place... :-)
- mwcampbell 6y agoJust remember that if you make it harder for OCR to produce accurate text from an image, you also make it harder for blind people to read it.
- cs702 6y agoThe output file size relative to other approaches will depend on the contents of the input file (e.g., does it embed any bitmaps, or is it only text in non-rasterized fonts?), the density you use (e.g., 150 dpi is 4x greater than 75 dpi), the bit depth you use (3 bits is 4x greater than 1 bit), and whether you add noise or not. Also, the one-line command above your comment is short/easy to remember and reasonably fast -- which is useful if you're impatient like me. All that said, note that you can always add a `-compress <compression method>` to the convert command, although this could make it noticeably slower, say, for a directory full of long documents. There's even a Fax TIFF compression method that makes the document look like it came out of one of those fax machines you see in movies from the 1980's. To get a list of supported compression methods, type `convert -list compress` at the command line.
- mNovak 6y agoFor other noobish windows users like myself, you can simply dump the following into a bat file. When run, it'll look for a file called "scanThis.pdf" and apply the conversion with ImageMagick. IF EXIST scanThis.pdf (magick convert -density 100 scanThis.pdf -colorspace gray +noise Gaussian -rotate 0.5 -depth 2 SCANNED.pdf) ELSE (ECHO File scanThis.pdf not found & PAUSE)
- stormdennis 6y agoSorry, I'm a long term Windows user but not very proficient. That can't be there entire contents of the bat file, can it? What else goes in there?
- mNovak 6y agoNope that's it. The bat file here is just a clickable shortcut so you don't have to remember the whole command. The interesting stuff is happening in ImageMagick, which has to be installed already.
- stormdennis 6y agoOk thanks, that's interesting. I might give it a shot
- cristaloleg 6y agoSounds like a plan to compile it into WASM and run locally inside any browser. To be honest, I'm waiting for a boom of such services, that can be run in a separate tab without any network jumps.
- so_serious 6y agoIt should be '-dAutoFilterColorImages=true' instead of 'dAutoFilterColorImages=true' for the gs command.