Add README and update examples.

README.md

@@ -0,0 +1,58 @@
+# Triangulizor
+
+<img src="https://github.com/mccutchen/triangulizor/raw/master/examples/in.jpg" align="middle">
+➡☁➡
+<img src="https://github.com/mccutchen/triangulizor/raw/master/examples/out.png" align="middle">
+
+## Usage
+
+Triangulizor requires Python 2.7+ and the [Python Imaging Library][3]. First,
+install `PIL` (usually this is as easy as `pip install pil`). Next, find an
+image to triangulize! To generate the example above, either of these commands
+will do the trick:
+
+```bash
+./triangulizor.py --debug --tile-size=16 examples/in.jpg
+```
+
+The `--debug` flag will cause the resulting image to be displayed immediately
+instead of written to `stdout` or to disk. You can also pass in the URL to an
+image that you want to process:
+
+```bash
+./triangulizor.py --debug --tile-size=16 https://github.com/mccutchen/triangulizor/raw/master/examples/in.jpg
+```
+
+All command line options are given below:
+
+```bash
+$ ./triangulizor.py --help
+```
+
+```
+usage: triangulizor.py [-h] [-t TILE_SIZE] [-v] [-vv] [-d] [infile] [outfile]
+
+Applies a "triangular pixel" effect to an image.
+
+positional arguments:
+  infile                Image to process (path or URL; defaults to STDIN)
+  outfile               Output file (defaults to STDOUT)
+
+optional arguments:
+  -h, --help            show this help message and exit
+  -t TILE_SIZE, --tile-size TILE_SIZE
+                        Tile size (must be divisible by 2; defaults to 20)
+  -v, --verbose         Verbose output
+  -vv                   Very verbose output
+  -d, --debug           Immediately display image instead of writing to
+                        OUTFILE.
+```
+
+## Credits
+
+This was inspired entirely by [this awesomely helpful blog post][1] by
+[@revdancatt][2].
+
+[1]: http://revdancatt.com/2012/03/31/the-pxl-effect-with-javascript-and-canvas-and-maths/
+[2]: http://twitter.com/revdancatt
+[3]: http://pypi.python.org/pypi/PIL

triangulizor.py

@@ -1,13 +1,5 @@
 #!/usr/bin/env python2.7
 
-"""
-triangulizor.py
-
-Applies a "triangular pixel" effect to images. Inspired by:
- * http://revdancatt.com/2012/03/31/the-pxl-effect-with-javascript-and-canvas-and-maths/
- * https://github.com/revdancatt/GuardianAmbientHeadlineRadio
-"""
-
 import argparse
 from cStringIO import StringIO
 import logging
@@ -210,7 +202,8 @@ def even_int(x):
         help='Image to process (path or URL; defaults to STDIN)')
     arg_parser.add_argument(
         'outfile', nargs='?', default=sys.stdout,
-        type=argparse.FileType('wb'))
+        type=argparse.FileType('wb'),
+        help='Output file (defaults to STDOUT)')
     arg_parser.add_argument(
         '-t', '--tile-size', type=even_int, default=20,
         help='Tile size (must be divisible by 2; defaults to 20)')