Improve snapshot handling to support different image formats

- Save snapshot as a temporary file before decoding, allowing better handling of JFIF or non-standard JPEG formats.
- Improved error handling for invalid or corrupted image data.

dayglo_detector/dayglo_detector.py

@@ -5,6 +5,7 @@ import numpy as np
 import cv2
 import base64
 import json
+import tempfile
 
 # Configuration
 MQTT_BROKER = os.environ.get('MQTT_BROKER', '10.59.221.172')
@@ -69,15 +70,19 @@ def process_snapshot(payload):
     print("Processing snapshot...")
     try:
         image_data = base64.b64decode(payload)
-        nparr = np.frombuffer(image_data, np.uint8)
-        image = cv2.imdecode(nparr, cv2.IMREAD_COLOR)
+        with tempfile.NamedTemporaryFile(suffix=".jpg", delete=False) as temp_image_file:
+            temp_image_file.write(image_data)
+            temp_image_path = temp_image_file.name
+
+        # Attempt to read the saved image with OpenCV
+        image = cv2.imread(temp_image_path)
 
         if image is not None:
             rating = calculate_dayglo_rating(image)
             print("Dayglo Rating calculated:", rating)
             publish_rating(rating)
         else:
-            print("Invalid image received")
+            print("Invalid image format or corrupted image received")
     except Exception as e:
         print(f"Error processing snapshot: {e}")