allow setting size and cropping of snapshots and best.jpg endpoint

config/config.example.yml

@@ -162,6 +162,13 @@ cameras:
     ################
     take_frame: 1
 
+    ################
+    # MQTT settings
+    ################
+    # mqtt:
+    #   crop_to_region: True
+    #   snapshot_height: 300
+
     ################
     # This will save a clip for each tracked object by frigate along with a json file that contains
     # data related to the tracked object. This works by telling ffmpeg to write video segments to /cache

detect_objects.py

@@ -381,10 +381,14 @@ def main():
     @app.route('/<camera_name>/<label>/best.jpg')
     def best(camera_name, label):
         if camera_name in CONFIG['cameras']:
-            best_frame = object_processor.get_best(camera_name, label)
-            if best_frame is None:
-                best_frame = np.zeros((720,1280,3), np.uint8)
-
+            best_object = object_processor.get_best(camera_name, label)
+            best_frame = best_object.get('frame', np.zeros((720,1280,3), np.uint8))
+            
+            crop = bool(request.args.get('crop', 0))
+            if crop:
+                region = best_object.get('region', [0,0,300,300])
+                best_frame = best_frame[region[1]:region[3], region[0]:region[2]]
+            
             height = int(request.args.get('h', str(best_frame.shape[0])))
             width = int(height*best_frame.shape[1]/best_frame.shape[0])
 

frigate/object_processing.py

@@ -254,6 +254,14 @@ class TrackedObjectProcessor(threading.Thread):
         
         def snapshot(camera, obj):
             best_frame = cv2.cvtColor(obj['frame'], cv2.COLOR_RGB2BGR)
+            mqtt_config = self.camera_config.get('mqtt', {'crop_to_region': False})
+            if mqtt_config.get('crop_to_region'):
+                region = obj['region']
+                best_frame = best_frame[region[1]:region[3], region[0]:region[2]]
+            if 'snapshot_height' in mqtt_config: 
+                height = int(mqtt_config['snapshot_height'])
+                width = int(height*best_frame.shape[1]/best_frame.shape[0])
+                best_frame = cv2.resize(best_frame, dsize=(width, height), interpolation=cv2.INTER_AREA)
             ret, jpg = cv2.imencode('.jpg', best_frame)
             if ret:
                 jpg_bytes = jpg.tobytes()
@@ -310,9 +318,9 @@ class TrackedObjectProcessor(threading.Thread):
     def get_best(self, camera, label):
         best_objects = self.camera_states[camera].best_objects
         if label in best_objects:
-            return best_objects[label]['frame']
+            return best_objects[label]
         else:
-            return None
+            return {}
     
     def get_current_frame(self, camera):
         return self.camera_states[camera].current_frame