Beer With Subtitles: Paperwork

Paperwork

April 20, 2023

The pandemic's not over - but travel is back. I'll even be in China again soon. I prepared the paperwork for my visa application using just a smartphone and some free software. Without access to an office-style printer/scanner, ID cards and passports were the trickiest to scan.

Here's how I did it. I hope this makes the process a little easier for someone else but please bear in mind I'm a nerd who already had the required software installed.

Tools

I rely on these free tools to wrangle JPEGs and PDFs:

https://github.com/myollie/img2pdf, to create PDFs from JPEGs
https://github.com/rrthomas/pdfjam, to join together PDFs in interesting ways, e.g. N-up/booklet printing

Since both tools have a lot of dependencies, I install and run them in a Docker container which I can throw away afterwards.

Open a terminal, cd to some directory in which you'll place your "scanned" images, and fire up the tools:

docker run -ti -v `pwd`:/work -w /work ubuntu:kinetic
apt update && apt install -y img2pdf texlive-extra-utils

Passports

Passports measure 125mm across; they're covered by ID-3 of ISO/IEC 7810.

We need a one-page PDF containing an image of your passport, at approximately the right size. This is exactly what img2pdf does:

You'll need a JPEG of your passport. I use Adobe Scan: it straightens and de-skews and processes backgrounds/textures to look a little like a photocopy. Whatever tool you use, crop as close to the edges as you can.
Copy the JPEG to your working directory. Rename it passport.jpeg.
Create a single-page, A4 PDF containing this JPEG, centred, at approximately the right dimensions:
```
img2pdf passport.jpeg -o passport.pdf -S A4 -s 125mm
```

ID Cards

ID cards (and credit cards, and many others) measure 85.6mm wide; that's ID-1 of ISO/IEC 7810.

I like to place the back and front of ID cards on the same page. Thanks to a nice property of ISO 216, this is straightforward: combine two single-page A5 landscape PDFs into one A4 single-page PDF.

You'll need a JPEG of the front and back of your card. Again, crop as close to the edges as you can. Copy them to your working directory. Rename them front.jpeg and back.jpeg.

Create a single-page, A4 PDF containing both JPEGs at approximately the right dimensions:

img2pdf front.jpeg -o front.pdf -S A5^T -s 85.6mm
img2pdf back.jpeg -o back.pdf -S A5^T -s 85.6mm
pdfjam --nup 1x2 front.pdf back.pdf -o idcard.pdf

Joining it all together

You may want to supply all your paperwork in one file. This is easy with pdfjam:

pdfjam passport.pdf idcard.pdf -o paperwork.pdf

Notes and Troubleshooting

Adobe Scan is only free "as in beer". You'll need to create an Adobe account if you don't already have one. Other apps are available!
If you find the PDFs too large (they'll be the size of your images plus a few bytes), scale down the image first. This is straightforward with ImageMagick:
```
magick passport.jpeg -scale 800x passport-small.jpeg
```
Passports don't tend to lie flat. I found it helpful to place a large clear sheet of plastic or glass on top.
Sorry, I don't know of a similarly-elegant way to place the front and back of ID cards onto a single sheet of Letter-sized paper.

#travels

#howto