Added colour optimisation function

A new function handles correct rendering of images (especially text) by converting grey areas to black.

settings/configuration.py

@@ -35,17 +35,14 @@ else:
 top_section_width = middle_section_width = bottom_section_width = display_width
 
 if top_section and bottom_section:
-  print('top and bottom section occupied')
   top_section_height = int(display_height*0.11)
   bottom_section_height = int(display_height*0.24)
 
 elif top_section and not bottom_section:
-  print('top section occupied')
   top_section_height = int(display_height*0.11)
   bottom_section_height = 0
 
 elif bottom_section and not top_section:
-  print('bottom_section occupied')
   top_section_height = 0
   bottom_section_height = int(display_height*0.24)
 
@@ -245,6 +242,13 @@ def image_cleanup():
       os.remove(temp_files)
   print('Done')
 
+def optimise_colours(image, threshold=220):
+  buffer = numpy.array(image.convert('RGB'))
+  red, green = buffer[:, :, 0], buffer[:, :, 1]
+  buffer[numpy.logical_and(red <= threshold, green <= threshold)] = [0,0,0] #grey->black
+  image = Image.fromarray(buffer)
+  return image
+
 def calibrate_display(no_of_cycles):
   """How many times should each colour be calibrated? Default is 3"""
   epaper = driver.EPD()