First public commit.

lenser/bbc/convert/mono.py

@@ -0,0 +1,15 @@
+"""BBC monochrome -- MODE 0's 640x256 black & white, exposed as the standard
+``mono`` mode for cross-platform parity (tone carried by dithering)."""
+from __future__ import annotations
+
+from . import mode0
+
+WIDTH, HEIGHT, PIXEL_ASPECT = mode0.WIDTH, mode0.HEIGHT, mode0.PIXEL_ASPECT
+
+
+def convert(img_rgb, palette_name="bbc", dither_mode="floyd",
+            intensive=False, base_color=None):
+    conv = mode0.convert(img_rgb, palette_name, dither_mode, intensive,
+                         base_color=base_color)
+    conv.mode = "mono"
+    return conv