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- Hacker News
- Is there something wrong with the pictures in the second half of the article? It seems like they are taking forever to load (about 30 seconds each), one at a time. I’m on mobile (iOS).by Diti
- I thought it might be a case of accidental huge image files (well I haven't checked the network tab) but it seems to be normal sized images loading at ~5 kB/s for me.
i.e. server is probably overloaded due to this story being on the front page.
by andai - 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.
by waltbosz - I wonder if having another normal camera capturing at the same time to assist with stitching images together will be easier than measuring acceleration? The normal camera doesn't need to have high resolution, just enough to align the images.by tvbusy
- Taken to the extreme....
I gotta wonder. Owen from RanOutOnARail could make some incredible wide pictures from his journeys if he had this setup. Been watching his YouTube channel for years [0], [1]. He has a Patreon account with more videos [2].
He use to have a lot more videos on YouTube. It's illegal to ride trains the way he does, but his videos helped get me through the long time of the covid pandemic after I would stop work for the day.
[0] https://youtube.com/@ranoutonarail?si=ElAeMpcrJASsE3Ov
by ggerules - Taking this to the extreme is doing this from space, which is how many imaging satellites actually work.by russdill
- As someone who also did some line scan photography, I also ran into a lot of similar challenges!
> Displaying and sharing the pictures I've taken has been a pain throughout the project. Most software on my computer doesn't like how big they are, and the most reliable tool I've found for viewing them has been GNU IMP, which feels a bit overkill.
I vibe-coded my own image viewer, sriv, to address this: https://github.com/dllu/sriv
Also, I found that displaying the images with multiple rows instead of a single super wide image is a lot more ergonomic.
> I correct for it for a given subject by shifting the red and blue channels to line up with the green channel. Since the lines are evenly spaced, I can shift by the same amount in opposite directions rather than having to measure separate offsets for each channel. In theory, I could decide how far to shift by correlating brightness shifts across channels, but at present, I do it manually.
I implemented the correlation-based approach: https://daniel.lawrence.lu/blog/2025-09-21-line-scan-camera-...
Recently, I also vibe-coded a tool for me to manually annotate constraints to fine-tune the distortion correction: https://daniel.lawrence.lu/blog/2026-08-02-line-scan-camera-...
For a stationary camera imaging a train, you just need to estimate the train's speed. But for the inverse problem of imaging the landscape from a moving train, the speed varies due to parallax (near things move faster, far things move slower), so there's no way to fully eliminate the RGB fringing for all distances.
> The biggest one is to make it not dependent on a laptop to capture images, which will make it less sketchy and easier to bring places.
I did just that recently, by adding an NVIDIA Jetson Orin Nano and a 7" 2000 nit touchscreen as well as a custom-designed CNC aluminum case: https://daniel.lawrence.lu/blog/2026-06-12-standalone-cnc-li...
by dllu - very impressed by the images you got, zero choppinessby otherayden
- The final quality of your photos is really impressive and your blog post was a good read on image processing.by y04nn
- 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 turnsby strohwueste
- Ohhh, nice; happy to have a chat on the subject; suggest a messaging option to discuss further if you're interested. Check out keybase on my profile for some listed contact options; you can also use the padlock symbol in the menubar there to PGP encrypt a message to me and share that through any suitable channel that can handle that ascii.
Edit: I've captured and extracted-to-textured-mesh Mirker Bahnhof before it got covered by the scaffolding; if you're going to do another recording I'd highly recommend you include an IMU recording and ideally (though much less critically) a GNSS raw measurements recording that includes carrier phase. I've got a recorder for the latter that exposes a simple USB-serial port that should work great unless the GTW15 windows are EMI-shielding (but iirc they aren't).
by namibj - 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.by awwaiid
- 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/
by otherayden - by mhb
- (17 days ago, 85 points, 34 comments)by Terr_
- 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?
by a1o - Recycling comment from another submission 17 day ago:
> Random thought: If you stick a very small adhesive mirror to the outside window before boarding, then footage "looking down" at the regularly-spaced railroad ties could contribute to information about the current speed and acceleration.
> Well, on a straight section anyway, if you turn, the inner/outer edges will appear differently-spaced...
> Wouldn't do anything positive in terms of suspicious staff though. They might think it's like some kind of heist-movie that will involve a specialized glass cutter making a circle on the window.
by Terr_ - 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:
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".
by jonty - This is super cool!by focusedone
- This was fun to play around with
- I see a blank page with the tab title "S L I T S C A N S P A ...". Scrolling does nothing. What's supposed to be there?by Aachen
- 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
by decae - Gorgeous!by jacquesm
- These are so adorable!by otherayden
- Had to think for a moment to understand the "Tokyo enters the dark night" shot.
Very beautiful and very clever. Loved it.
by srean - 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.
by msisk6 - > It was a fun little project; the speed of the trains affected the horizontal compression of the images.
A few years ago I took a photo out the window of a Shinkansen going 150 mph and was amused that everything in the foreground tilted significantly to the left because of this effect. This is about as close as I'll get to seeing what it's like to get sucked into a black hole.
by kmoser