app.py

from pathlib import Path
import torch
import gradio as gr
from torch import nn

LABELS = Path("class_names.txt").read_text().splitlines()

model = nn.Sequential(
    nn.Conv2d(1, 32, 3, padding="same"),
    nn.ReLU(),
    nn.MaxPool2d(2),
    nn.Conv2d(32, 64, 3, padding="same"),
    nn.ReLU(),
    nn.MaxPool2d(2),
    nn.Conv2d(64, 128, 3, padding="same"),
    nn.ReLU(),
    nn.MaxPool2d(2),
    nn.Flatten(),
    nn.Linear(1152, 256),
    nn.ReLU(),
    nn.Linear(256, len(LABELS)),
)
state_dict = torch.load("pytorch_model.bin", map_location="cpu")
model.load_state_dict(state_dict, strict=False)
model.eval()


def predict(im):
    if isinstance(im, dict):  # For sketchpad input
        im = im['composite']
    
    # Convert to grayscale and resize to 28x28
    import cv2
    im_gray = cv2.cvtColor(im, cv2.COLOR_RGB2GRAY)
    im_resized = cv2.resize(im_gray, (28, 28))

    # Convert to tensor and normalize
    x = torch.tensor(im_resized, dtype=torch.float32).unsqueeze(0).unsqueeze(0) / 255.0

    with torch.no_grad():
        out = model(x)

    probabilities = torch.nn.functional.softmax(out[0], dim=0)
    values, indices = torch.topk(probabilities, 5)
    return {LABELS[i]: v.item() for i, v in zip(indices, values)}


interface = gr.Interface(
    predict,
    inputs="sketchpad",
    outputs="label",
    theme="huggingface",
    title="Sketch Recognition",
    description="Who wants to play Pictionary? Draw a common object like a shovel or a laptop, and the algorithm will guess in real time!",
    article="<p style='text-align: center'>Sketch Recognition | Demo Model</p>",
    live=True,
)
interface.launch(share=True)