Only calculate brightness based on the calculated ambient color, remo…

…ve ignore black feature, make 0% minimum brightness the default

amby/cli.py

@@ -9,7 +9,7 @@
 
 from amby.config import get_saved_username, save_username
 from amby.constants import SUCCESS_EXIT_CODE, FAILURE_EXIT_CODE, PHILIPS_MAX_BRIGHTNESS, PHILIPS_MIN_BRIGHTNESS
-from amby.core import get_average_color, get_pixel_data, get_relative_brightness, rgb_to_xy
+from amby.core import get_average_color, get_pixel_data, rgb_to_xy, get_relative_luminance
 
 argument_parser = argparse.ArgumentParser()
 argument_parser.add_argument('bridge_address', help='The domain or IP address of the Philips Hue Bridge')
@@ -31,16 +31,11 @@
     help='Specify which percentage of brightest colors to average in luminance mode')
 argument_parser.add_argument(
     '--change-brightness', '-b', action='store_true',
-    help='Adjust brightness of lights based on the overall relative luminance of the specified region. '
-         'Very CPU intensive!')
+    help='Adjust brightness of lights based on the overall relative luminance of the specified screen')
 argument_parser.add_argument(
-    '--min-brightness', '-m', type=float, default=50, help='Minimum brightness in percent')
+    '--min-brightness', '-m', type=float, default=0, help='Minimum brightness in percent')
 argument_parser.add_argument(
     '--max-brightness', '-M', type=float, default=100, help='Maximum brightness in percent')
-argument_parser.add_argument(
-    '--dont-ignore-black', '-B', dest='ignore_black', action='store_false',
-    help="Don't ignore absolutely black pixels. Absolutely black pixels are ignored by default because of the black "
-         "bars added by video players if the aspect ratio doesn't match, which skews the results")
 
 
 def stderr(*args, **kwargs):
@@ -86,11 +81,10 @@ def change_light_states(state):
             data = get_pixel_data(arguments.screen)
             color = get_average_color(data)
             if color != previous_color:
-                state = {'xy': rgb_to_xy(*color)}
+                state = {'xy': rgb_to_xy(color)}
                 if arguments.change_brightness:
-                    state['bri'] = max(
-                        min_brightness,
-                        int(round(get_relative_brightness(data, arguments.ignore_black) * max_brightness)))
+                    state['bri'] = max(min_brightness, int(round(get_relative_luminance(color) * max_brightness)))
+
                 change_light_states(state)
 
             if arguments.run_once:

amby/core.py

@@ -1,8 +1,6 @@
 import numpy as np
 import rgbxy
 
-from amby.constants import PHILIPS_MAX_BRIGHTNESS
-
 try:
     import PyQt5
     from PyQt5.QtWidgets import QApplication
@@ -11,8 +9,8 @@
     PyQt5 = None
 
 # https://en.wikipedia.org/wiki/Relative_luminance
-_luminance_multipliers = np.array([0.2126, 0.7152, 0.0722])
-_max_luminance = np.dot([255, 255, 255], _luminance_multipliers)
+_white_color = 255, 255, 255
+_luminance_multipliers = 0.2126, 0.7152, 0.0722
 _last_image_reference = None
 _color_converter = rgbxy.Converter()
 
@@ -45,26 +43,23 @@ def get_pixel_data(screen=None, region=None):
         raise Exception('no screenshot provider available')
 
 
-def get_average_color(data):
-    return tuple(np.average(data, axis=0).round().astype(int))
+def _get_absolute_luminance(color):
+    return sum(x * y for x, y in zip(color, _luminance_multipliers))
+
+
+_max_luminance = _get_absolute_luminance(_white_color)
 
 
-def get_relative_brightness(data, ignore_black):
-    max_brightness = _max_luminance * data.shape[0]
-    luminance = np.dot(data, _luminance_multipliers)
-    absolute_brightness = np.sum(luminance, axis=0)
+def get_relative_luminance(color):
+    return _get_absolute_luminance(color) / _max_luminance
 
-    if ignore_black:
-        # Act like absolutely black pixels have a neutral effect on the absolute brightness by multiplying their amount
-        # with half of the maximum brightness
-        black_pixels = data.shape[0] - np.count_nonzero(luminance)
-        absolute_brightness += PHILIPS_MAX_BRIGHTNESS / 2 * black_pixels
 
-    return absolute_brightness / max_brightness
+def get_average_color(data_matrix):
+    return tuple(np.average(data_matrix, axis=0).round().astype(int))
 
 
-def rgb_to_xy(r, g, b):
+def rgb_to_xy(color):
     # Prevent DivisionByZero exception in rgbxy library:
     # https://github.com/benknight/hue-python-rgb-converter/issues/6
-    r, g, b = tuple(max(component, 10 ** -3) for component in (r, g, b))
-    return _color_converter.rgb_to_xy(r, g, b)
+    color = tuple(max(component, 10 ** -3) for component in color)
+    return _color_converter.rgb_to_xy(*color)