update stuff

README copy.md

@@ -1,2 +0,0 @@
-# pySTC
-A Python interface for [Syndrome Trellis Codes](http://dde.binghamton.edu/download/syndrome/) Steganography 

README.md

@@ -1,6 +1,6 @@
 ---
 title: Stego
-emoji: 👀
+emoji: 🔎
 colorFrom: purple
 colorTo: purple
 sdk: gradio

app.py

@@ -8,7 +8,16 @@ from PIL import Image
 
 
 title = "Steganography"
-description = "Explore hiding messages in images using content adaptive steganography and STCs. Python implementation by Daniel Lerch https://github.com/daniellerch/pySTC"
+description =  '''Explore hiding messages in images using content adaptive steganography and STCs (Syndrome Trellis Codes).
+               http://dde.binghamton.edu/download/syndrome/ .
+               We use HILL https://ieeexplore.ieee.org/document/7025854 .
+               Python implementation adapted from Daniel Lerch's https://github.com/daniellerch/pySTC .
+               To encode:
+               Drag and drop a PNG file, write a message and enter a key (remember the key).
+               To decode:
+               Drap and drop the stego file, enter the key.
+               Note that this software is supplied "as is," without any services or guaranties.
+               '''
 
 def HILL(input_image, operation, message, key):
     input_image.seek(0)
@@ -28,11 +37,11 @@ def HILL(input_image, operation, message, key):
             [-1,  2, -1]])
         L1 = np.ones((3, 3)).astype('float32')/(3**2)
         L2 = np.ones((15, 15)).astype('float32')/(15**2)
-        costs = signal.convolve2d(I, H, mode='same')  
+        costs = signal.convolve2d(I, H, mode='same', boundary='symm')  
         costs = abs(costs)
-        costs = signal.convolve2d(costs, L1, mode='same')  
+        costs = signal.convolve2d(costs, L1, mode='same', boundary='symm')  
         costs = 1/costs
-        costs = signal.convolve2d(costs, L2, mode='same')  
+        costs = signal.convolve2d(costs, L2, mode='same', boundary='symm')  
         costs[costs == np.inf] = 1
         stc.embed('tmp/file.png', costs, message, key, 'tmp/stego.png')
         return 'tmp/stego.png'