更新功能

backend/app/services/image_processing.py

@@ -0,0 +1,46 @@
+"""Optional image metadata and computer-vision hints for image observations."""
+
+from __future__ import annotations
+
+import io
+from typing import Any
+
+
+def image_metadata(data: bytes) -> dict[str, Any]:
+    """Read safe image metadata without changing the original upload."""
+    try:
+        from PIL import Image, ImageOps
+        with Image.open(io.BytesIO(data)) as image:
+            normalized = ImageOps.exif_transpose(image)
+            return {
+                "width": int(normalized.width),
+                "height": int(normalized.height),
+                "format": str(image.format or "").lower(),
+                "orientation": "landscape" if normalized.width >= normalized.height else "portrait",
+                "has_alpha": "A" in normalized.getbands(),
+            }
+    except Exception as error:
+        return {"error": f"image metadata unavailable: {type(error).__name__}"}
+
+
+def cv_hints(data: bytes) -> dict[str, Any]:
+    """Return conservative CV hints; OpenCV is intentionally optional."""
+    try:
+        import cv2  # type: ignore
+        import numpy as np  # type: ignore
+    except Exception:
+        return {"available": False, "hints": []}
+    try:
+        image = cv2.imdecode(np.frombuffer(data, dtype=np.uint8), cv2.IMREAD_GRAYSCALE)
+        if image is None:
+            return {"available": True, "hints": [], "error": "image decode failed"}
+        edges = cv2.Canny(image, 50, 150)
+        lines = cv2.HoughLinesP(edges, 1, 3.141592653589793 / 180, threshold=50, minLineLength=30, maxLineGap=8)
+        line_hints = []
+        for line in (lines[:32] if lines is not None else []):
+            x1, y1, x2, y2 = [int(value) for value in line[0]]
+            line_hints.append({"type": "line", "start_px": [x1, y1], "end_px": [x2, y2]})
+        return {"available": True, "hints": line_hints, "edge_pixels": int((edges > 0).sum())}
+    except Exception as error:
+        return {"available": True, "hints": [], "error": f"cv failed: {type(error).__name__}"}
+