Added image merging script

This merges the image for the black and coloured images into a single one.

images/merger.py

@@ -0,0 +1,31 @@
+from PIL import Image
+import numpy
+
+module_name = 'inkycal_agenda'
+
+
+def merge(module_name, out_filename):
+  """Merge black pixels from image2 into image 1
+  module_name = name of the module generating the image
+  out_filename = what name to give to the finished file
+  """
+  
+  im1_name, im2_name = module_name+'.png', module_name+'_colour.png'
+  im1 = Image.open(im1_name).convert('RGBA')
+  im2 = Image.open(im2_name).convert('RGBA')
+
+  def clear_white(img):
+    """Replace all white pixels from image with transparent pixels
+    """
+    x = numpy.asarray(img.convert('RGBA')).copy()
+    x[:, :, 3] = (255 * (x[:, :, :3] != 255).any(axis=2)).astype(numpy.uint8)
+    return Image.fromarray(x)
+
+  im2 = clear_white(im2)
+  im1.paste(im2, (0,0), im2)
+  im1.save(out_filename+'.png', 'PNG')
+
+merge(module_name, module_name+'2')
+
+
+print('Done')