Fixes to app.py-1

app.py

@@ -1,7 +1,6 @@
 import gradio as gr
 import numpy as np
 
-rng = range(1,225)
 
 sobel_verticle = np.array([[-1,0,1],
                                [-1,0,1],
@@ -31,7 +30,7 @@ def apply_kernel(ch, kernel):
     return out_ch
 def convolve(img, kernel):
     ch1, ch2, ch3 = img[:,:,0], img[:,:,1], img[:,:,2] 
-    out_img = np.concatenate([apply_kernel(ch1, kernel), apply_kernel(ch2, kernel), apply_kernel(ch3, kernel)])
+    out_img = np.dstack((apply_kernel(ch1, kernel), apply_kernel(ch2, kernel), apply_kernel(ch3, kernel)))
     return out_img