Files
SnapOtter/packages/ai/python/detect_faces.py
T
Siddharth Kumar Sah 92d4d2d9c6 feat(smart-crop): overhaul with face detection, social presets, and 3 modes
Replace the confusing 2-mode smart crop with a clear 3-mode system:
- Subject Focus: Sharp attention/entropy saliency crop with social media presets
- Face Focus: MediaPipe face detection with headshot framing presets
- Auto Trim: Border removal with optional pad-to-square

Adds detectFaces() to AI package, face preset constants, backward
compatibility for old mode names, and comprehensive integration tests.
2026-04-13 00:47:53 +08:00

130 lines
4.3 KiB
Python

"""Face detection and blurring using MediaPipe."""
import sys
import json
def emit_progress(percent, stage):
"""Emit structured progress to stderr for bridge.ts to capture."""
print(json.dumps({"progress": percent, "stage": stage}), file=sys.stderr, flush=True)
def main():
input_path = sys.argv[1]
output_path = sys.argv[2]
settings = json.loads(sys.argv[3]) if len(sys.argv) > 3 else {}
blur_radius = settings.get("blurRadius", 30)
sensitivity = settings.get("sensitivity", 0.5)
detect_only = settings.get("detectOnly", False)
try:
emit_progress(10, "Preparing")
from PIL import Image, ImageFilter
img = Image.open(input_path).convert("RGB")
try:
import mediapipe as mp
import numpy as np
emit_progress(20, "Ready")
# Map sensitivity (0.1-0.9) to MediaPipe confidence threshold.
# Higher sensitivity = lower confidence threshold = more detections.
min_confidence = max(0.1, 1.0 - sensitivity)
img_array = np.array(img)
mp_face = mp.solutions.face_detection
# Try short-range model first (model_selection=0, best for faces
# within ~2m which covers most photos), then fall back to
# full-range model (model_selection=1) for distant/group shots.
emit_progress(25, "Scanning for faces")
results = None
for model_sel in [0, 1]:
detector = mp_face.FaceDetection(
model_selection=model_sel,
min_detection_confidence=min_confidence,
)
results = detector.process(img_array)
detector.close()
if results.detections:
break
faces = []
detections = results.detections or []
num_faces = len(detections)
emit_progress(50, f"Found {num_faces} face{'s' if num_faces != 1 else ''}")
if num_faces > 0:
ih, iw = img_array.shape[:2]
for i, detection in enumerate(detections):
bbox = detection.location_data.relative_bounding_box
x = int(bbox.xmin * iw)
y = int(bbox.ymin * ih)
w = int(bbox.width * iw)
h = int(bbox.height * ih)
if not detect_only:
# Add padding around the face
pad = int(max(w, h) * 0.1)
x1 = max(0, x - pad)
y1 = max(0, y - pad)
x2 = min(img.width, x + w + pad)
y2 = min(img.height, y + h + pad)
face_region = img.crop((x1, y1, x2, y2))
blurred = face_region.filter(
ImageFilter.GaussianBlur(blur_radius)
)
img.paste(blurred, (x1, y1))
emit_progress(
50 + int((i + 1) / num_faces * 40),
f"Blurring face {i + 1} of {num_faces}",
)
faces.append({"x": x, "y": y, "w": w, "h": h})
if not detect_only:
emit_progress(95, "Saving result")
img.save(output_path)
print(
json.dumps(
{
"success": True,
"facesDetected": len(faces),
"faces": faces,
}
)
)
except ImportError:
print(
json.dumps(
{
"success": False,
"error": "Face detection requires MediaPipe. Install with: pip install mediapipe",
}
)
)
sys.exit(1)
except ImportError:
print(
json.dumps(
{
"success": False,
"error": "Pillow is not installed. Install with: pip install Pillow",
}
)
)
sys.exit(1)
except Exception as e:
print(json.dumps({"success": False, "error": str(e)}))
sys.exit(1)
if __name__ == "__main__":
main()