cv2_enumerate_cameras(CAP_AVFOUNDATION) probes indices 0-99 through
OpenCV's AVFoundation backend, which intermittently segfaults (exit
code 139) when invalid device indices are probed. Replace with a
bounded cv2.VideoCapture loop (range(10)) that safely skips
unavailable indices.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Replace float64 with float32 in apply_mouth_area() blending masks —
float32 provides sufficient precision for 8-bit image blending and
halves memory bandwidth
- Use float32 in apply_mask_area() mask computations
- Vectorize hull padding loop in create_face_mask() (face_masking.py)
replacing per-point Python loop with NumPy array operations
- Fix apply_color_transfer() to use proper [0,1] LAB conversion —
cv2.cvtColor with float32 input expects [0,1] range, not [0,255]
- Pre-compute inverse masks to avoid repeated (1.0 - mask) subtraction
- Use np.broadcast_to instead of np.repeat for face mask expansion
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add a dedicated detection thread that runs face detection continuously
on the latest captured frame and publishes results to a shared dict.
The processing/swap thread reads cached detection results instead of
running detection inline, so it never blocks on the 15-30ms detection
cost.
Architecture change: 2 threads → 3 threads
Before: capture → [detect + swap] → display
After: capture → swap (uses cached detections) → display
↘ detect (async, writes to shared cache) ↗
Also replaces the blocking while/ROOT.update() display loop with
ROOT.after()-based scheduling, which avoids Tk event loop re-entrancy
issues and UI freezes.
Closes#1664
In Tk 9.0, Menu.index("end") returns "" instead of raising TclError
on empty menus. CustomTkinter's DropdownMenu._add_menu_commands
doesn't handle this case, causing a crash when creating CTkOptionMenu
widgets (e.g., the camera selector dropdown).
Add a monkey-patch that guards against the empty-string return value.
