randomize names

app.py

@@ -1,10 +1,10 @@
-import gradio as gr
 import stc
-import numpy as np
-import imageio
-from scipy import signal
 import cv2 
+import random
+import numpy as np
+import gradio as gr
 from PIL import Image
+from scipy import signal
 
 
 title = "Steganography"
@@ -13,22 +13,23 @@ description =  '''Explore hiding messages in images using content adaptive stega
                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).
+               Drag and drop a PNG file, write a message and enter a key (remember the key), the generated image has the secret message encoded.
                To decode:
-               Drap and drop the stego file, enter the key.
-               Note that this software is supplied "as is," without any services or guaranties.
+               Drag and drop the stego file that you just generated, enter the key.
+               Note that this software is supplied "as is," without any services or security guaranties.
                '''
 
 def HILL(input_image, operation, message, key):
+    tmp_name = str(random.randint(100,1000))
     input_image.seek(0)
     buffer = input_image.read()
     I = cv2.imdecode(np.frombuffer(buffer, np.uint8), 1)
     I = cv2.cvtColor(I,cv2.COLOR_BGR2GRAY)
-    cv2.imwrite('tmp/file.png',I)
+    cv2.imwrite('tmp/'+tmp_name+'.png',I)
 
     if operation == 'decode': 
-        stc.extract('tmp/file.png', key, 'tmp/output.txt')
-        return 'tmp/output.txt'
+        stc.extract('tmp/'+tmp_name+'.png', key, 'tmp/'+tmp_name+'.txt')
+        return 'tmp/'+tmp_name+'.txt'
     
     else: 
         H = np.array(
@@ -43,8 +44,8 @@ def HILL(input_image, operation, message, key):
         costs = 1/costs
         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'
+        stc.embed('tmp/'+tmp_name+'.png', costs, message, key, 'tmp/'+tmp_name+'.png')
+        return 'tmp/'+tmp_name+'.png'
 
 iface = gr.Interface(HILL, 
                     ['file', gr.inputs.Radio(['encode', 'decode']), 'text', 'text'], 

stc.py

@@ -122,6 +122,7 @@ def embed(input_img_path, cost_matrix,  msg_file_path, password, output_img_path
         if i<len(msg_bits):
             message[i] = msg_bits[i]
         else:
+            # This doesn't look optimal
             message[i] = 0
     # Hide message
     stego = (c_int*(width*height))()