Change image format of gallery

app.py

@@ -41,7 +41,7 @@ def split_image(image, parts, direction='horizontal'):
 
 
 css = "#file {height: 10vh;}"
-result_image = gr.Gallery(height="45vh")
+result_image = gr.Gallery(height="45vh", format="png")
 with gr.Blocks(css=css) as demo: 
     with gr.Tabs():
         with gr.Tab(label="Split") as tab_split:
@@ -56,7 +56,7 @@ with gr.Blocks(css=css) as demo:
             with gr.Row():
                 with gr.Column():
                     merge_files = gr.File(file_count="multiple", elem_id="file")
-                    merge_preview = gr.Gallery(label="prevew", height="35vh")
+                    merge_preview = gr.Gallery(label="prevew", height="35vh", format="png")
                 with gr.Column():
                     merge_direction = gr.Radio(label="Direction", choices=["vertical", "horizontal"], value="vertical", interactive=True) 
                     merge_b_resize = gr.Checkbox(label="Resize to first image", value=True, interactive=True)