app.py

import gradio as gr
import torch
import torchvision.transforms as transforms
from PIL import Image

# Define the CNN model
class CNN(torch.nn.Module):
    def __init__(self):
        super(CNN, self).__init__()
        self.conv1 = torch.nn.Conv2d(1, 32, kernel_size=3, stride=1, padding=1)
        self.conv2 = torch.nn.Conv2d(32, 64, kernel_size=3, stride=1, padding=1)
        self.pool = torch.nn.MaxPool2d(2, 2)
        self.fc1 = torch.nn.Linear(64 * 14 * 14, 128)
        self.fc2 = torch.nn.Linear(128, 10)
        self.relu = torch.nn.ReLU()
        self.dropout = torch.nn.Dropout(0.25)

    def forward(self, x):
        x = self.relu(self.conv1(x))
        x = self.pool(self.relu(self.conv2(x)))
        x = x.view(x.size(0), -1)  # Flatten dynamically based on batch size
        x = self.relu(self.fc1(x))
        x = self.dropout(x)
        x = self.fc2(x)
        return x

# Load the trained model
model = CNN()
model.load_state_dict(torch.load("pytorch_model.bin", map_location=torch.device('cpu'), weights_only=True))
model.eval()

# Define the prediction function
def predict(image):
    transform = transforms.Compose([
        transforms.Grayscale(),  # Ensure the input image is grayscale
        transforms.Resize((28, 28)),  # Resize the image to 28x28 pixels
        transforms.ToTensor(),
        transforms.Normalize((0.5,), (0.5,))  # Normalize the image
    ])
    image_tensor = transform(image).unsqueeze(0)  # Add batch dimension
    with torch.no_grad():
        output = model(image_tensor)
        predicted_class = output.argmax(dim=1).item()  # Get the predicted class
    return f"Predicted digit: {predicted_class}"

# Create the Gradio interface
interface = gr.Interface(
    fn=predict,
    inputs=gr.Image(type="pil"),  # Updated input component
    outputs="text",
    title="Handwritten Digit Classifier",
    description="Upload an image of a handwritten digit, and the model will predict the digit."
)

# Launch the Gradio app
if __name__ == "__main__":
    interface.launch()  # Removed share=True for Hugging Face Spaces