Update app.py

app.py

@@ -144,7 +144,8 @@ def linscale(linear):
     return int(math.log2(linear))
 
 def loadf(f):
-    f = f.sort()
+    if f != None:
+        f = f.sort()
     return f
 
 
@@ -176,7 +177,7 @@ with gr.Blocks() as demo:
         gr.HTML(title)
         with gr.Row():
             with gr.Column():
-                files_input = gr.File(file_count="directory")
+                files_input = gr.File(file_count="multiple", file_types=['image'])
                 gallery_input = gr.Gallery(label="Slides", preview=True, columns=8192, interactive=False)
                 files_input.change(fn=loadf, inputs=[files_input], outputs=[gallery_input])
                 with gr.Row():