Added example usage and fixed an important typo in the main code

.gitignore

@@ -0,0 +1,67 @@
+
+# Created by https://www.gitignore.io/api/c++,macos
+# Edit at https://www.gitignore.io/?templates=c++,macos
+
+### C++ ###
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+
+### macOS ###
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+# End of https://www.gitignore.io/api/c++,macos

README.md

@@ -6,13 +6,13 @@ output is printed on transparency film and overlaid.  The
 [dithercrypt program](dithercrypt/dithercrypt.py) supports
 four variants:
 
-* "encrypt2" encrypts a single image into two output grids.  Taken
+* "encrypt2" encrypts single image into two output grids.  Taken
   individually, the grids are random noise.  If overlaid, the image is
   revealed.  Black areas of the secret image will appear entirely black;
   white areas will be half black and half white; and gray areas will
   be more than half black and less than half white.
 
-* "encrypt3" encrypts a three images into three output grids.  Taken
+* "encrypt3" encrypts three images into three output grids.  Taken
   individually, the grids are random noise.  If two grids are
   overlaid, one of the three input images will be revealed.  Black
   areas of the secret image will appear entirely black; white areas
@@ -37,10 +37,15 @@ gamma.
 To print the results, you'll need to use a program that will give
 pixelated output instead of trying to interpolate.
 
+Example usage:
+```
+python /path/to/dithercrypt.py encrypt2 /path/to/inputimage.jpg output1.jpg output2.jpg
+```
+
 # Visual cryptography workshop
 
 This is a placeholder.  It's very awkward to use right now.
 
 # License
 
-MIT
+MIT

dithercrypt/dithercrypt.py

@@ -20,7 +20,7 @@ def save_img(img, fn):
 
 def encrypt2(img):
     shape = img.shape
-    
+
     out1 = np.zeros(shape, dtype=np.uint8)
     out2 = np.zeros(shape, dtype=np.uint8)
 
@@ -41,7 +41,7 @@ def steg2(clear1, clear2, secret):
     shape = clear1.shape
     if shape != clear2.shape or shape != secret.shape:
         raise TypeError('all three images must have the same shape')
-    
+
     out1 = np.zeros(shape, dtype=np.uint8)
     out2 = np.zeros(shape, dtype=np.uint8)
 
@@ -192,7 +192,7 @@ def encrypt4(img_ab, img_ac, img_ad, img_bc, img_bd, img_cd):
     return (out_a, out_b, out_c, out_d)
 
 commands = [
-    ('encrypt2', 2, 2, encrypt2),
+    ('encrypt2', 1, 2, encrypt2),
     ('steg2', 3, 2, steg2),
     ('encrypt3', 3, 3, encrypt3),
     ('encrypt4', 6, 4, encrypt4),

index.php

@@ -0,0 +1,3 @@
+<?php
+require_once("website/index.php")
+?>

website/css/index.css

@@ -0,0 +1,43 @@
+body {
+	font-size: 11pt;
+	margin: 3em;
+	background: #fff;
+	color: #444;
+	max-width: 100%;
+    font-family: monospace;
+}
+
+h1 {
+	text-transform: uppercase;
+    font-size: 1em;
+}
+
+h2 {
+	font-size: 1em;
+	text-transform: uppercase;
+    margin-top: 1em;
+}
+
+section a {
+	color: #444;
+	display: block;
+	margin: 0;
+}
+
+a:hover {
+	color: #268bd2;
+}
+
+.postdate {
+	color: #CCC;
+}
+
+@media (max-width: 1080px) {
+	body {
+		margin: 3em;
+		font-size: 20pt;
+	}
+	a {
+		margin-top: 0.25em;
+	}
+}

website/css/style.css

@@ -0,0 +1,103 @@
+body {
+  color: #000;
+  background: #FFF;
+
+  max-width: 30em;
+  margin: 6em 3em 6em 6em;
+
+  font-family: sans-serif;
+  font-style: normal;
+  font-size: 11pt;
+  line-height: 1.5;
+}
+
+h1, h2, h3, h4 {
+  margin-bottom: 0;
+  padding-bottom: 0;
+  font-size: 1em;
+}
+
+p {
+  margin-top: 0.5em;
+  margin-bottom: 0;
+  text-align: left;
+  hyphenate: auto;
+  hyphenate-before:2;
+  hyphenate-after:3;
+}
+
+/* all paragraphs that are proceeded by another paragraph. tiny paragraphs don't
+ * count */
+p:not(.tiny) + p, figure + p {
+  margin-top: 0;
+  text-indent: 1.5em;
+}
+
+p.tiny, #bottom {
+  margin-top: 1em;
+  1argin-bottom: 1em;
+  text-indent: 0;
+  color: #CCC;
+}
+
+img {
+  width: 100%;
+}
+
+figcaption {
+  margin-top: 0.5em;
+}
+
+figure {
+  margin: 1.5em 8em;
+  padding: 2em 0;
+  max-width: 600px;
+}
+
+@media (max-width: 700px) {
+	figure {
+		margin: 1.5em 0;
+	}
+}
+
+pre {
+  margin: 1em 2em;
+}
+
+pre code {
+    background: none;
+    font-size: 1em;
+}
+
+code {
+  background: rgba(0, 0, 0, 0.05);
+  padding: .2em;
+  font-size: .8em;
+}
+
+a {
+  color: #268bd2;
+  text-decoration: none;
+}
+
+a:hover {
+  color: #1a6192;
+}
+
+#header, header {
+  float: left;
+  width: 100%;
+  line-height: 1.3;
+  padding-bottom: 4em;
+}
+
+#header h1, header h1 {
+  padding: 50px 0 0 0;
+  margin: 0;
+}
+
+#header h2, header h2 {
+  margin: 0;
+  color: #CCC;
+}
+

website/index.php

@@ -0,0 +1,16 @@
+<?php
+echo "test";
+?>
+
+
+<html>
+  <head>
+    <title>barkin | viusal cryptography</title>
+    <meta charset="utf-8" />
+    <link href="css/style.css" rel="stylesheet">
+    <link href="css/index.css" rel="stylesheet">
+  </head>
+  <body>
+
+  </body>
+</html>