update.

app.py

@@ -1,7 +1,15 @@
+import numpy as np
 import gradio as gr
 
-def greet(name):
-    return "Hello " + name + "!!"
+def sepia(input_img):
+    sepia_filter = np.array([
+        [0.393, 0.769, 0.189], 
+        [0.349, 0.686, 0.168], 
+        [0.272, 0.534, 0.131]
+    ])
+    sepia_img = input_img.dot(sepia_filter.T)
+    sepia_img /= sepia_img.max()
+    return sepia_img
 
-iface = gr.Interface(fn=greet, inputs="text", outputs="text")
-iface.launch()
+demo = gr.Interface(sepia, gr.Image(shape=(200, 200)), "image")
+demo.launch()