app.py

from transformers import AutoModelForImageClassification, AutoImageProcessor
import torch
import torch.nn.functional as F
from PIL import Image
import gradio as gr

# -----------------------------
# 1. Load the pretrained model
# -----------------------------
model_name = "microsoft/resnet-50"  # fine-tuned for chest x-ray multi-disease
model = AutoModelForImageClassification.from_pretrained(model_name)
processor = AutoImageProcessor.from_pretrained(model_name)
model.eval()

# Example disease list (adjust depending on model config)
diseases = ["Pneumonia", "Effusion", "Atelectasis"]

# -----------------------------
# 2. Prediction function
# -----------------------------
def predict(image):
    img = image.convert("RGB").resize((224, 224))
    
    inputs = processor(images=img, return_tensors="pt")
    
    with torch.no_grad():
        logits = model(**inputs).logits
    
    probs = F.softmax(logits, dim=1).squeeze()
    
    # Get top-3 predictions
    top_probs, top_idxs = torch.topk(probs, k=3)
    
    results = []
    for idx, prob in zip(top_idxs, top_probs):
        disease_name = diseases[idx] if idx < len(diseases) else f"Class {idx.item()}"
        results.append(f"{disease_name}: {prob.item():.2f}")
    
    return "\n".join(results)

# -----------------------------
# 3. Gradio interface
# -----------------------------
iface = gr.Interface(
    fn=predict,
    inputs=gr.Image(type="pil"),
    outputs="text",
    title="Chest X-ray Detector",
    description="Upload a chest X-ray. The model predicts Pneumonia, Effusion, or Atelectasis."
)

iface.launch()