Using the railway network as a flatbed scanner

(philo.gay)

148 points | by otherayden 2 hours ago

20 comments

  • waltbosz 2 minutes ago
    The wobbly pictures brings me back to my experience as a kid with hand-held photo scanners https://oldcomputer.info/pc/apscan/index.htm .

    It was impossible (for me at least) to get a scan without shifting my hand position on the X-axis while also sliding the scanner down the picture.

    Also, I seem to recall the scanner I used was only capable of outputting 1-bit dithered black and white pictures. This was late 80s/early 90s tech.

  • msisk6 1 hour ago
    Ward Cunningham and I did something similar back in 2008.

    We were both at a startup in Portland and our office was along the railroad tracks east of the Willamette. We were up on the 4th or 5th floor right above a lot of train traffic including Amtrak.

    I brought in some extra Mac gear I had including one of the early iSight cameras which back then was an external device you stuck on the top of your display and connected to the Mac via FireWire. We set it up and rolled the desk over to the window in the office and turned the camera around pointing down at the tracks and Ward got to work hacking something up to do a slit scan.

    It was a fun little project; the speed of the trains affected the horizontal compression of the images. We could tweak the software to expand or contract the size of the image by adjusting the number of slit scans per unit of time. Of course, that affected the exposure but I recall the camera having some automatic adjustments that gave us trouble.

    That's about all we did with it. Just a quick afternoon hacking project. Neither of us thought much about it at the time so we didn't save anything.

  • decae 54 minutes ago
    I've posted this here before but I have been creating animations using a similar process with a regular camera and manually splicing the frames together. [1,2,3] The effect is quite interesting in how it forces focus on the subject reducing the background into an abstract pattern. Each 'line' is around 15px wide. I think I went through exactly the same thought process as the author, funny how ideas can come up independently like this.

    [1] https://youtube.com/shorts/VQuI1wW8hAw [2] https://youtube.com/shorts/vE6kLolf57w [3] https://youtube.com/shorts/QxvFyasQYAY

    I also shot a timelapse of the Tokyo skyline at sunset and applied a similar process [4], then motion tracked it so that time is traveling across the frame from left to right[5]. Each line here is 4 pixels wide and the original animation is in 8k.

    [4] https://youtu.be/wTma28gwSk0 [5] https://youtu.be/v5HLX5wFEGk

  • exe34 1 minute ago
    That's clever! I had the idea to use video to remove things like fences by moving the recording device, but never got around to implementing it.
  • awwaiid 1 hour ago
    I love this sort of project and write-up. Inspiring to try something a bit different and dance on that line between practicality and artwork. The in-progress "scans" are themselves an interesting stretching of time and space, even if they aren't what the artist is ultimately going for.
    • otherayden 1 hour ago
      Same here. I'm especially a big fan of the "using x as y" format (using youtube as a mountable file system, using my wii to host a web server, etc). I feel like they're a lot less common on here these days than a year or 2 ago

      edit: I made this site to only show non-ai related posts like this one https://www.unslop.news/

  • jonty 1 hour ago
    If you want to play around with slit scanning, I made this little toy a number of years ago and frequently find myself using it on trains:

    https://slitscan.space

    Press and hold your phone screen to switch between the front/back cameras, or hit "c" on a computer. Tapping the screen saves the image, as does "s".

  • sandblast 4 minutes ago
    Too bad the author is ill. Very sad.
  • mhb 1 hour ago
    • a1o 1 hour ago
      I am curious, is it the same person?

      Also, I think at some point someone shared some Japanese website where someone did these high quality photos of Japanese trains with a similar technique?

      • toomuchtodo 1 hour ago
        Same person. This is the blog post, the other thread is the CCC talk.
  • andrewla 34 minutes ago
    This project is more deeply technical but one thing I find fun is to take a video from a moving train and create a video stereogram by having one eye lagging in time/distance behind the other eye, letting you create very long baseline stereograms.

    It's fun to be able to see the 3d effects on passing bridges, etc., and for large baselines on long straight stretches you can see the 3d structure of clouds in a fascinating way.

  • cscheid 27 minutes ago
    This is so cool. It's a much better version of what Bill Cheswick and I did almost 15 years ago with footage from a SFO->EWR flight: https://cscheid.net/static/windowseat/
  • strohwueste 57 minutes ago
    Great writeup! Planned doing the same thing Herr in germany. Thought a Smartphone camera would be enough but there no way to access the camera2 api for those highspeed recordings. I took 1h long 240hz 4k vertikal videos (out of the Schwebebahn in Wuppertal) which could be displayed by MacOS preview. Right no im waiting for a good gaussian splatting tool to create the driving of the "Train” in Blender. The newest Lingbot-map is unfurtunatly not really trained for sideway movement. I always asked myself if the sideway movement and the Parallaxe would make way easier to infer the distance and the 3d scanning capabilities because the pixel only really move one as long you dont drive turns
  • hn9zmdcaou 19 minutes ago
    The honesty is what makes it good
  • adamjb 1 hour ago
    Not quite in the same spirit but I suppose one could talk of railway operators using the railway network as a flatbed scanner when they send maintenance vehicles out to scan the railbed for defects.

    For example: https://railgallery.wongm.com/ev120-inspection-vehicle/F144_... https://www.youtube.com/watch?v=5TKDw2E_PBQ

  • dorfsmay 1 hour ago
    Nice. It reminds me of a blog of a guy who had mounted a flatbed scanner on an electrical motor to make a digital photo before digital camera existed. He had added one of the resulting picture of his backyard. It was one of the most viral Slashdot post at the time.
  • mhb 1 hour ago
    Lynx photo finish cameras. Same idea:

    https://www.finishlynx.com/

  • Tepix 1 hour ago
    Has anyone done the same for other rides with wheels? I guess that would end up being NeRF (Neural Radiance Fields) & Gaussian splatting?
  • mofosyne 1 hour ago
    Reminds me of when railways attempted to attach linear barcodes on their train and read it using a similar method
  • grumbelbart2 1 hour ago
    Railway operators do this to inspect tracks: Mount a line-scan camera that looks down, get an "infinite" image of the tracks, inspect for anything interesting.
  • 13hours 48 minutes ago
    This is how satellites (mostly) take pictures.