Files
nissaphotobooth/README.md
trav 13b210935f Add camera selection diagnostics
resolve_device now prints each by-id candidate it scans, which entry
matched, and the resolved device path; the no-match error lists all
by-id entries with their targets. Camera startup logs the raw config
setting, resolved path, the node's sysfs name, the OpenCV version, and
the negotiated resolution. 'python3 camera.py' now dumps every detected
camera before opening, to troubleshoot machines where the wrong camera
gets used.
2026-07-18 15:21:32 -04:00

4.7 KiB
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CRT Photobooth

A fullscreen photobooth for a Linux laptop mirrored to a 4:3 CRT. Guests press the button (any mouse button) to take a 3-photo shoot with countdowns and flashes. After 4 shoots, all 12 photos are printed on one contact sheet. When idle for 5 minutes, a fish-tank screensaver protects the CRT from burn-in.

Setup on a new laptop

  1. Install Python 3.11 or newer (check with python3 --version).

  2. Install the dependencies:

    pip install pygame-ce opencv-python pillow
    

    Note: it's pygame-ce, not pygame — the community edition has wheels for newer Python versions. If pip refuses because the system Python is "externally managed", either use pip install --user ... or create a virtual environment:

    python3 -m venv ~/photobooth-venv
    ~/photobooth-venv/bin/pip install pygame-ce opencv-python pillow
    # then run with: ~/photobooth-venv/bin/python photobooth.py
    
  3. Plug in the Macally webcam and confirm Linux sees it:

    ls /dev/v4l/by-id/
    

    You should see something like usb-SolidYear_Macally_USB2.0Camera-video-index0. The default config finds it automatically by name.

  4. Set up the printer. The booth prints via CUPS with the lp command. Check what's configured and set a default:

    lpstat -p          # list printers
    lpoptions -d NAME  # set the default printer
    lpstat -p -d       # verify: should show a default destination
    

    Print a test page from the printer settings GUI to make sure it works before an event.

  5. Copy this whole folder to the laptop and run it:

    python3 photobooth.py
    

    Add --windowed to test in a window instead of fullscreen. Press Esc or Q to quit.

Customizing

  • All settings live in config.toml — camera choice, screen text, countdown lengths, screensaver timeout, printer options. Comments in the file explain each one.
  • Idle screen background: replace assets/background.png (any size, it gets scaled to the screen — 4:3 looks best, e.g. 800×600).
  • Fish: drop your fish drawings into the fish/ folder as PNGs with transparent backgrounds. Draw them facing right — the program flips them automatically when they swim left. Bubbles come out of the front (mouth) end. Delete placeholder_fish.png once you have real fish.

Switching cameras

In config.toml, device = "auto-macally" finds the Macally cam by name. To use a different camera:

  • device = "auto-integrated" — match another camera by (partial) name from ls /dev/v4l/by-id/, case-insensitive
  • device = "/dev/video2" — an exact device path
  • device = "0" — a plain index

Where things go

  • photos/ — individual shots for the current print cycle. Deleted automatically after a successful print. (If the program is restarted mid-cycle, photos here are counted so no progress is lost.)
  • contact_sheets/ — every printed sheet, kept as a backup in case of printer trouble. Delete them manually now and then, or set delete_contact_sheets = true in the config to remove each one right after it prints.

If printing fails

The booth doesn't lose anything: the contact sheet is saved in contact_sheets/, an error shows on the idle screen, and you can print the sheet by hand with:

lp -o media=letter -o fit-to-page contact_sheets/sheet_XXXX.jpg

Common causes: printer off or unplugged (lpstat -p says "disabled" — re-enable with cupsenable PRINTER_NAME), or no default printer set.

Troubleshooting the camera

Test the camera on its own (uses the device from config.toml):

python3 camera.py

It first prints a pre-flight dump of every camera the system sees (/dev/v4l/by-id/ names, device nodes, and what each node identifies as), then reports which device was matched, resolved, and opened, plus the OpenCV version. If the booth ever uses the wrong camera, run this and read the output — it shows exactly where the selection went sideways.

If it reports black frames (or the live preview shows a warning): the Macally cam's chipset sometimes wedges and streams pure black until it is power-cycled. Unplug the camera, plug it back in, and restart the program. Worth doing a quick test shoot at the start of an event.

Heads-up

  • The Brother HL-5470DW is a monochrome laser — contact sheets print in black & white.
  • The live preview is mirrored (like a mirror) so posing feels natural, but saved photos are not mirrored. Set mirror_preview = false to change that.
  • CRT overscan may crop the very edges of the screen; once the CRT is connected, adjust text positions/sizes in code or the CRT's own controls.