diff --git a/platypush/backend/http/app/utils/routes.py b/platypush/backend/http/app/utils/routes.py
index b27fa4ca1..f7de249da 100644
--- a/platypush/backend/http/app/utils/routes.py
+++ b/platypush/backend/http/app/utils/routes.py
@@ -30,8 +30,7 @@ def get_routes():
             if hasattr(module, '__routes__'):
                 routes.extend(module.__routes__)
         except Exception as e:
-            logger.warning('Could not import module %s', mod_name)
-            logger.exception(e)
+            logger().warning('Could not import module %s: %s', mod_name, str(e))
             continue
 
     return routes
diff --git a/platypush/plugins/camera/model/camera.py b/platypush/plugins/camera/model/camera.py
index 3791f201b..851000213 100644
--- a/platypush/plugins/camera/model/camera.py
+++ b/platypush/plugins/camera/model/camera.py
@@ -3,8 +3,6 @@ import threading
 from dataclasses import asdict, dataclass
 from typing import Optional, Union, Tuple, Set
 
-import numpy as np
-
 from platypush.plugins.camera.model.writer import (
     StreamWriter,
     VideoWriter,
@@ -78,6 +76,8 @@ class Camera:
         Calculates the effective resolution of the camera in pixels, taking
         into account the base resolution, the scale and the rotation.
         """
+        import numpy as np
+
         assert self.info.resolution, 'No base resolution specified'
         rot = (self.info.rotate or 0) * math.pi / 180
         sin = math.sin(rot)
diff --git a/platypush/plugins/camera/model/writer/__init__.py b/platypush/plugins/camera/model/writer/__init__.py
index a24d780f7..89f4e311d 100644
--- a/platypush/plugins/camera/model/writer/__init__.py
+++ b/platypush/plugins/camera/model/writer/__init__.py
@@ -7,8 +7,6 @@ import time
 from abc import ABC, abstractmethod
 from typing import Optional, IO
 
-from PIL.Image import Image
-
 from platypush.utils import get_redis
 
 
@@ -28,11 +26,12 @@ class VideoWriter(ABC):
         self.closed = False
 
     @abstractmethod
-    def write(self, image: Image):
+    def write(self, image):
         """
         Write an image to the channel.
 
         :param image: PIL Image instance.
+        :type image: PIL.Image.Image
         """
         raise NotImplementedError()
 
@@ -88,7 +87,7 @@ class StreamWriter(VideoWriter, ABC):
         self.redis_queue = redis_queue
         self.sock = sock
 
-    def write(self, image: Image):
+    def write(self, image):
         data = self.encode(image)
         with self.ready:
             if self.buffer.closed:
@@ -116,7 +115,7 @@ class StreamWriter(VideoWriter, ABC):
             get_redis().publish(self.redis_queue, data)
 
     @abstractmethod
-    def encode(self, image: Image) -> bytes:
+    def encode(self, image) -> bytes:
         """
         Encode an image before sending it to the channel.
 
diff --git a/platypush/plugins/camera/model/writer/ffmpeg.py b/platypush/plugins/camera/model/writer/ffmpeg.py
index 41011e393..d31f9efce 100644
--- a/platypush/plugins/camera/model/writer/ffmpeg.py
+++ b/platypush/plugins/camera/model/writer/ffmpeg.py
@@ -5,8 +5,6 @@ import time
 from abc import ABC
 from typing import Optional, Tuple
 
-from PIL.Image import Image
-
 from platypush.plugins.camera.model.camera import Camera
 from platypush.plugins.camera.model.writer import (
     VideoWriter,
@@ -73,7 +71,7 @@ class FFmpegWriter(VideoWriter, ABC):
     def is_closed(self):
         return self.closed or not self.ffmpeg or self.ffmpeg.poll() is not None
 
-    def write(self, image: Image):
+    def write(self, image):
         if self.is_closed():
             return
 
@@ -146,7 +144,7 @@ class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
         self._reader = threading.Thread(target=self._reader_thread)
         self._reader.start()
 
-    def encode(self, image: Image) -> bytes:
+    def encode(self, image) -> bytes:
         return image.convert('RGB').tobytes()
 
     def _reader_thread(self):
@@ -173,7 +171,7 @@ class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
 
             self._sock_send(self.frame)
 
-    def write(self, image: Image):
+    def write(self, image):
         if self.is_closed():
             return