Hiding image

Untested

steginack.py

@@ -2,20 +2,43 @@
 
 from PIL import Image
 import argparse
+from eta import ETA
+
+get_bin = lambda x, n: x >= 0 and str(bin(x))[2:].zfill(n) or "-" + str(bin(x))[3:].zfill(n)
+# From http://stackoverflow.com/a/21732313/2766106
 
 
 def hideInFile(infile, hidefile, bits, outfile):
     inim = Image.open(infile)
     hideim = Image.open(hidefile)
     assert inim.size == hideim.size, "Both image must be of the same size"
+    assert 0 <= bits <= 8
     outim = Image.new('RGB', inim.size)
+    eta = ETA(inim.size[0] * inim.size[1])
+    for x in range(inim.size[0]):
+        for y in range(inim.size[1]):
+            incol = inim.getpixel((x, y))
+            hidecol = inim.getpixel((x, y))
+            outcol = []
+            for cp in range(len(incol)):
+                inbyt = get_bin(incol[cp], 8)
+                hidebyt = get_bin(hidecol[cp], 8)
+                outbyt = list(inbyt)
+                for bit in range(bits):
+                    outbyt[-bit - 1] = inbyt[1]
+                outcol.append(int(''.join(outbyt), 2))
+            outim.putpixel((x, y), tuple(outcol))
+            eta.print_status(x * inim.size[1] + y)
+    eta.done()
     inim.close()
     hideim.close()
     outim.save(outfile, 'PNG')
 
+
 def inverseFile(infile, bits, outfile):
     inim = Image.open(infile)
     outim = Image.new('RGB', inim.size)
+    assert 0 <= bits <= 8
     inim.close()
     outim.save(outfile, 'PNG')