A-M baby

Task/Grayscale-image/Python/grayscale-image.py

@@ -0,0 +1,53 @@
+# String masquerading as ppm file (version P3)
+import io
+ppmfileout = io.StringIO('')
+
+def togreyscale(self):
+    for h in range(self.height):
+        for w in range(self.width):
+            r, g, b = self.get(w, h)
+            l = int(0.2126 * r + 0.7152 * g + 0.0722 * b)
+            self.set(w, h, Colour(l, l, l))
+
+Bitmap.togreyscale = togreyscale
+
+
+# Draw something simple
+bitmap = Bitmap(4, 4, white)
+bitmap.fillrect(1, 0, 1, 2, Colour(127, 0, 63))
+bitmap.set(3, 3, Colour(0, 127, 31))
+print('Colour:')
+# Write to the open 'file' handle
+bitmap.writeppmp3(ppmfileout)
+print(ppmfileout.getvalue())
+print('Grey:')
+bitmap.togreyscale()
+ppmfileout = io.StringIO('')
+bitmap.writeppmp3(ppmfileout)
+print(ppmfileout.getvalue())
+
+
+'''
+The print statement above produces the following output :
+
+Colour:
+P3
+# generated from Bitmap.writeppmp3
+4 4
+255
+   255 255 255   255 255 255   255 255 255     0 127  31
+   255 255 255   255 255 255   255 255 255   255 255 255
+   255 255 255   127   0  63   255 255 255   255 255 255
+   255 255 255   127   0  63   255 255 255   255 255 255
+
+Grey:
+P3
+# generated from Bitmap.writeppmp3
+4 4
+254
+   254 254 254   254 254 254   254 254 254    93  93  93
+   254 254 254   254 254 254   254 254 254   254 254 254
+   254 254 254    31  31  31   254 254 254   254 254 254
+   254 254 254    31  31  31   254 254 254   254 254 254
+
+'''