adding explanation of usage on the gradio app

app.py

@@ -6,7 +6,12 @@ import os
 from tqdm import tqdm
 from PIL import Image
 
-def main(image1, image2, refine='False'):
+def process_image(image1, image2, refine='False'):
+    """ Process a pair of images to swap their backgrounds.
+    image1: PIL image of the first image.
+    image2: PIL image of the second image.
+    refine: if True, use an additional network in the inpainter to refine the background.\
+            useful in high-resolution images and large inpainting masks. It takes longer to run."""
        
     segmenter = Mask2FormerSegmenter()
     segmenter.load_models(checkpoint_name = "facebook/mask2former-swin-large-ade-semantic")
@@ -24,17 +29,22 @@ def main(image1, image2, refine='False'):
     return image_a, image_b
         
 
-def process_image(image1, image2, refine=False):
+def run_gradio_fn(image1, image2, refine=False):
+    """ Run the background swapper app on a pair of images."""
     img1 = Image.fromarray(image1.astype('uint8'), 'RGB')
     img2 = Image.fromarray(image2.astype('uint8'), 'RGB')
-    return main(img1, img2, refine)
+    return process_image(img1, img2, refine)
 
 
 iface = gr.Interface(
-    fn=process_image,
+    fn=run_gradio_fn,
     inputs=["image", "image", gr.inputs.Checkbox(label="Use Refiner on background")],
     outputs=["image", "image"],
     title="Background Swapper App",
-    description="Upload two images to see their backgrounds swapped.",
+    description="Upload two images to see their backgrounds swapped. \
+        The first image will have the background of the second image, and vice versa. \
+            Refiner option: Uses an additional network in the inpainter to refine the background.\
+            Useful in high-resolution images and large inpainting masks. \
+            It takes about 20s longer to run on 1024x1024",
 )
 iface.launch()