app.py

import gradio as gr
import torch
from transformers import SegformerForSemanticSegmentation, SegformerImageProcessor
import numpy as np
from PIL import Image

# Load model and processor
model_name = "nvidia/segformer-b0-finetuned-ade-512-512"
processor = SegformerImageProcessor.from_pretrained(model_name)
model = SegformerForSemanticSegmentation.from_pretrained(model_name)

# ADE20k color palette (simplified for visualization)
def create_color_map():
    # Create a colorful palette for visualization
    np.random.seed(42)
    return np.random.randint(0, 255, size=(150, 3), dtype=np.uint8)

color_map = create_color_map()

def segment_image(image):
    # Process the image
    inputs = processor(images=image, return_tensors="pt")
    
    # Get model prediction
    with torch.no_grad():
        outputs = model(**inputs)
        logits = outputs.logits
    
    # Get segmentation map
    seg = logits.argmax(dim=1)[0].cpu().numpy()
    
    # Convert to colored segmentation map
    colored_seg = np.zeros((seg.shape[0], seg.shape[1], 3), dtype=np.uint8)
    for label in np.unique(seg):
        colored_seg[seg == label] = color_map[label]
    
    # Convert to PIL image for display
    segmented_image = Image.fromarray(colored_seg)
    
    return [image, segmented_image]

# Create Gradio interface
demo = gr.Interface(
    fn=segment_image,
    inputs=gr.Image(type="pil"),
    outputs=[
        gr.Image(type="pil", label="Original"),
        gr.Image(type="pil", label="Segmented")
    ],
    title="Image Segmentation with SegFormer",
    description="Upload an image to segment it into different semantic regions using SegFormer model fine-tuned on ADE20K dataset."
)

# Launch the app
if __name__ == "__main__":
    demo.launch()