Extended features of MLX90640 infrared camera plugin

docs/source/conf.py

@@ -224,6 +224,7 @@ autodoc_mock_imports = ['googlesamples.assistant.grpc.audio_helpers',
                         'gps',
                         'picamera',
                         'pwm3901',
+                        'PIL',
                         ]
 
 sys.path.insert(0, os.path.abspath('../..'))

platypush/plugins/camera/ir/mlx90640/__init__.py

@@ -1,7 +1,11 @@
+import base64
+import math
 import os
 import subprocess
 import time
 
+from PIL import Image, ImageCms
+
 from platypush.plugins import Plugin, action
 
 
@@ -24,15 +28,20 @@ class CameraIrMlx90640Plugin(Plugin):
         $ make bcm2835
         $ make examples/rawrgb I2C_MODE=LINUX
 
+    Requires:
+
+        * **mlx90640-library** installation (see instructions above)
+        * **PIL** image library (``pip install Pillow``)
     """
 
     _img_size = (24, 32)
 
-    def __init__(self, fps=16, skip_frames=2, scale_factor=10, rawrgb_path=None, **kwargs):
+    def __init__(self, fps=16, skip_frames=2, scale_factor=10, rotate=0, rawrgb_path=None, **kwargs):
         """
         :param fps: Frames per seconds (default: 16)
         :param skip_frames: Number of frames to be skipped on sensor initialization/warmup (default: 2)
         :param scale_factor: The camera outputs 24x32 pixels artifacts. Use scale_factor to scale them up to a larger image (default: 10)
+        :param rotate: Rotation angle in degrees (default: 0)
         :param rawrgb_path: Specify it if the rawrgb executable compiled from
             https://github.com/pimoroni/mlx90640-library is in another folder than
             `<directory of this file>/lib/examples`.
@@ -47,19 +56,25 @@ class CameraIrMlx90640Plugin(Plugin):
         assert os.path.isfile(rawrgb_path)
 
         self.fps = fps
+        self.rotate = rotate
         self.skip_frames = skip_frames
         self.scale_factor = scale_factor
         self.rawrgb_path = rawrgb_path
 
     @action
-    def capture(self, frames=1, skip_frames=None):
+    def capture(self, frames=1, fps=None, skip_frames=None):
         """
         Capture one or multiple frames and return them as raw RGB
 
         :param frames: Number of frames to be captured (default: 1)
+        :param fps: If set it overrides the fps parameter specified on the object (default: None)
         :param skip_frames: If set it overrides the skip_frames parameter specified on the object (default: None)
+        :returns: list[str]. Each item is a base64 encoded raw RGB representation of a frame
         """
 
+        if fps is None:
+            fps = self.fps
+
         if skip_frames is None:
             skip_frames = self.skip_frames
 
@@ -71,16 +86,77 @@ class CameraIrMlx90640Plugin(Plugin):
                               stderr=subprocess.PIPE) as camera:
             while len(captured_frames) < frames:
                 frame = camera.stdout.read(input_size)
-                size = len(frame)
 
                 if skip_frames > 0:
                     time.sleep(sleep_time)
                     skip_frames -= 1
                     continue
 
+                frame = base64.encodebytes(frame).decode()
                 captured_frames.append(frame)
+                time.sleep(sleep_time)
 
-        return frames
+            camera.terminate()
+
+        return captured_frames
+
+    @action
+    def capture_to_file(self, output_image, frames=1, grayscale=False, fps=None, skip_frames=None, scale_factor=None, rotate=None):
+        """
+        Capture one or multiple frames to one or multiple image files.
+
+        :param output_image: Can be either the path to a single image file or a format string (e.g. 'snapshots/image-{:04d}') in case of multiple frames
+        :param fps: If set it overrides the fps parameter specified on the object (default: None)
+        :param frames: Number of frames to be captured (default: 1)
+        :param grayscale: Save the image as grayscale - black pixels will be colder, white pixels warmer (default: False)
+        :param skip_frames: If set it overrides the skip_frames parameter specified on the object (default: None)
+        :param scale_factor: If set it overrides the scale_factor parameter specified on the object (default: None)
+        :param rotate: If set it overrides the rotate parameter specified on the object (default: None)
+        :returns: list[str] containing the saved image file names
+        """
+
+        if scale_factor is None:
+            scale_factor = self.scale_factor
+
+        if rotate is None:
+            rotate = self.rotate
+
+        files = []
+
+        for i in range(0, frames):
+            encoded_frame = self.capture(frames=1, fps=fps, skip_frames=skip_frames).output[0]
+            frame = base64.decodebytes(encoded_frame.encode())
+            size = (self._img_size[1], self._img_size[0])
+            image = Image.frombytes('RGB', size, frame)
+            new_image = Image.new('L', image.size)
+
+            if grayscale:
+                for i in range(0, image.size[0]):
+                    for j in range(0, image.size[1]):
+                        r, g, b = image.getpixel((i, j))
+                        value = int(2.0*r - 0.5*g - 1.5*b)
+
+                        if value > 255:
+                            value = 255
+                        if value < 0:
+                            value = 0
+
+                        new_image.putpixel((i, j), value)
+
+                image = new_image
+
+            if rotate:
+                image = image.rotate(rotate)
+
+            if scale_factor != 1:
+                size = tuple(i*scale_factor for i in size)
+                image = image.resize(size, Image.ANTIALIAS)
+
+            filename = os.path.abspath(os.path.expanduser(output_image.format(i)))
+            image.save(filename)
+            files.append(filename)
+
+        return files
 
 
 # vim:sw=4:ts=4:et:

requirements.txt

@@ -165,3 +165,6 @@ pyScss
 
 # Support for PWM3901 2-Dimensional Optical Flow Sensor
 # pwm3901
+
+# Support for MLX90640 thermal camera
+# Pillow