feat(v1): add basic backend and frontend

backend/processing/storage.py

@@ -0,0 +1,57 @@
+from pathlib import Path
+from uuid import uuid4
+
+import cv2
+import numpy as np
+from django.conf import settings
+
+from .algorithms import ProcessingError, ensure_uint8, image_to_data_url
+
+
+def session_dir():
+    path = Path(settings.MEDIA_ROOT) / "sessions"
+    path.mkdir(parents=True, exist_ok=True)
+    return path
+
+
+def save_image_array(image, prefix="image"):
+    filename = f"sessions/{prefix}-{uuid4().hex}.png"
+    path = Path(settings.MEDIA_ROOT) / filename
+    path.parent.mkdir(parents=True, exist_ok=True)
+    rgb = ensure_uint8(image)
+    bgr = cv2.cvtColor(rgb, cv2.COLOR_RGB2BGR)
+    ok, encoded = cv2.imencode(".png", bgr)
+    if not ok:
+        raise ProcessingError("Unable to encode image for temporary storage.")
+    path.write_bytes(encoded.tobytes())
+    return filename
+
+
+def load_image_array(relative_path):
+    path = Path(settings.MEDIA_ROOT) / relative_path
+    if not path.exists():
+        raise ProcessingError("Temporary image file is missing or unreadable.")
+    raw = np.frombuffer(path.read_bytes(), dtype=np.uint8)
+    image = cv2.imdecode(raw, cv2.IMREAD_COLOR)
+    if image is None:
+        raise ProcessingError("Temporary image file is missing or unreadable.")
+    return cv2.cvtColor(image, cv2.COLOR_BGR2RGB).astype(np.uint8)
+
+
+def delete_relative_file(relative_path):
+    if not relative_path:
+        return
+    path = (Path(settings.MEDIA_ROOT) / relative_path).resolve()
+    media_root = Path(settings.MEDIA_ROOT).resolve()
+    if media_root not in path.parents and path != media_root:
+        return
+    if path.exists():
+        path.unlink()
+
+
+def payload_for_image(image, relative_path):
+    return {
+        "image_path": relative_path,
+        "image_url": f"{settings.MEDIA_URL}{relative_path}",
+        "image_data": image_to_data_url(image),
+    }