app.py

import streamlit as st
from PIL import Image
import jax
import jax.numpy as jnp  # JAX NumPy
import numpy as np
from flax import linen as nn  # Linen API
from huggingface_hub import HfFileSystem
from flax.serialization import msgpack_restore, from_state_dict
import time

LATENT_DIM = 100

class Generator(nn.Module):
  @nn.compact
  def __call__(self, latent, training=True):
    x = latent
    x = nn.Dense(features=64)(x)
    x = nn.BatchNorm(not training)(x)
    x = nn.relu(x)
    x = nn.Dense(features=2*2*512)(x)
    x = nn.relu(x)
    x = x.reshape((x.shape[0], 2, 2, -1))
    x = nn.ConvTranspose(features=256, kernel_size=(2, 2), strides=(2, 2))(x)
    x = nn.relu(x)
    x = nn.ConvTranspose(features=128, kernel_size=(2, 2), strides=(2, 2))(x)
    x = nn.relu(x)
    x = nn.ConvTranspose(features=64, kernel_size=(2, 2), strides=(2, 2))(x)
    x = nn.relu(x)
    x = nn.ConvTranspose(features=1, kernel_size=(2, 2), strides=(2, 2))(x)
    x = nn.tanh(x)
    return x

generator = Generator()
variables = generator.init(jax.random.PRNGKey(0), jnp.zeros([1, LATENT_DIM]), training=False)

fs = HfFileSystem()
with fs.open("PrakhAI/DigitGAN/g_checkpoint.msgpack", "rb") as f:
  g_state = from_state_dict(variables, msgpack_restore(f.read()))

def sample_latent(key):
  return jax.random.normal(key, shape=(1, LATENT_DIM))

if st.button('Generate Digit'):
  latents = sample_latent(jax.random.PRNGKey(int(1_000_000 * time.time())))
  g_out = generator.apply({'params': g_state['params'], 'batch_stats': g_state['batch_stats']}, latents, training=False)
  img = ((np.array(g_out)+1)*255./2.).astype(np.uint8)[0]
  st.image(Image.fromarray(np.repeat(img, repeats=3, axis=2)))
  st.write("The model's details are at https://huggingface.co/PrakhAI/DigitGAN/blob/main/README.md")