CamSnap — Camera Snapshot & Monitoring

Capture snapshots from connected cameras, detect changes between frames, and trigger alerts when motion or scene changes are detected.

Quick Start

# Capture a snapshot from the default camera
camsnap capture

# Capture from a specific camera
camsnap capture --camera front-door

# List available cameras
camsnap list

# Compare two snapshots
camsnap diff snapshot1.jpg snapshot2.jpg

# Watch mode — continuous monitoring with change detection
camsnap watch --interval 30 --threshold 0.05

Commands

Capture

camsnap capture [--camera <name>] [--output <path>] [--quality <1-100>]

List Cameras

camsnap list [--json]

Diff / Compare

camsnap diff <image-a> <image-b> [--threshold <float>] [--json]

Watch Mode

camsnap watch [--camera <name>] [--interval <seconds>] [--threshold <float>]
              [--on-change <command>] [--output-dir <path>]

History

camsnap history [--camera <name>] [--limit <n>] [--since <duration>]

Configuration

Configuration lives in ~/.config/camsnap/config.yaml:

cameras:
  default:
    device: /dev/video0
    resolution: 1920x1080
  front-door:
    device: /dev/video1
    resolution: 1280x720

watch:
  interval: 30
  threshold: 0.05
  output_dir: ~/.local/share/camsnap/snapshots
  on_change: null  # e.g. "notify-send 'CamSnap' 'Change detected'"

Output Format

camsnap capture --json

{
  "success": true,
  "data": {
    "path": "/home/user/.local/share/camsnap/snapshots/2026-08-01T03-45-00.jpg",
    "camera": "default",
    "resolution": "1920x1080",
    "size_bytes": 245760,
    "timestamp": "2026-08-01T03:45:00Z"
  }
}

camsnap diff --json

{
  "success": true,
  "data": {
    "diff_score": 0.12,
    "changed": true,
    "threshold": 0.05,
    "regions": [
      {"x": 120, "y": 80, "w": 200, "h": 300, "score": 0.34}
    ]
  }
}

Best Practices

1. Use watch mode with --on-change to trigger alerts or webhooks
2. Set appropriate thresholds — too low = false positives, too high = missed events
3. Archive snapshots to object storage for long-term retention
4. Use named cameras for multi-camera setups
5. Rotate old snapshots with camsnap history --prune --older-than 30d

Installation

npm install -g camsnap
# or from source
cargo install camsnap

License

MIT