app.py

import gradio as gr
import torch
import torch.nn as nn
from torchvision import models, transforms
from PIL import Image

# 1. SETUP MODEL
# We use ResNet18 structure to match your training
model = models.resnet18(weights=None) 
model.fc = nn.Linear(model.fc.in_features, 10) # Adjust head to 10 classes

# Load your 98.79% accuracy weights
try:
    state_dict = torch.load("fulldigits.pt", map_location="cpu")
    model.load_state_dict(state_dict)
    model.eval()
except Exception as e:
    print(f"Error loading model: {e}")

# 2. PREPROCESSING
# Must use the ImageNet stats you trained with!
transform = transforms.Compose([
    transforms.Lambda(lambda x: x.convert("RGB")), # Force RGB
    transforms.Resize((128, 128)),                 # Match training size
    transforms.ToTensor(),
    transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225])
])

# 3. PREDICT FUNCTION
def predict(image):
    if image is None: return None
    img_tensor = transform(image).unsqueeze(0)
    
    with torch.no_grad():
        output = model(img_tensor)
        probabilities = torch.nn.functional.softmax(output[0], dim=0)
    
    return {str(i): float(probabilities[i]) for i in range(10)}

# 4. INTERFACE
demo = gr.Interface(
    fn=predict,
    inputs=gr.Image(type="pil", label="Draw or Upload Digit"),
    outputs=gr.Label(num_top_classes=3),
    title="Handwritten Digit Recognizer",
    description="A ResNet18 model fine-tuned to 98.79% accuracy."
)

if __name__ == "__main__":
    demo.launch()