app.py

import sys
from subprocess import call
def run_cmd(command):
    try:
        print(command)
        call(command, shell=True)
    except KeyboardInterrupt:
        print("Process interrupted")
        sys.exit(1)

print("⬇️ Installing latest gradio==2.4.7b9")
run_cmd("pip install --upgrade pip")
run_cmd('pip install gradio==2.4.7b9')

import gradio as gr
import os
import random
import math
import numpy as np
import matplotlib.pyplot as plt

from enum import Enum
from glob import glob
from functools import partial

import tensorflow as tf
from tensorflow import keras
from tensorflow.keras import layers
from tensorflow.keras.models import Sequential
from tensorflow_addons.layers import InstanceNormalization

import tensorflow_datasets as tfds

# Model Definition

def log2(x):
    return int(np.log2(x))


def resize_image(res, sample):
    print("Call resize_image...")
    image = sample["image"]
    # only donwsampling, so use nearest neighbor that is faster to run
    image = tf.image.resize(
        image, (res, res), method=tf.image.ResizeMethod.NEAREST_NEIGHBOR
    )
    image = tf.cast(image, tf.float32) / 127.5 - 1.0
    return image


def create_dataloader(res):
    batch_size = batch_sizes[log2(res)]
    dl = ds_train.map(partial(resize_image, res), num_parallel_calls=tf.data.AUTOTUNE)
    dl = dl.shuffle(200).batch(batch_size, drop_remainder=True).prefetch(1).repeat()
    return dl

def fade_in(alpha, a, b):
    return alpha * a + (1.0 - alpha) * b


def wasserstein_loss(y_true, y_pred):
    return -tf.reduce_mean(y_true * y_pred)


def pixel_norm(x, epsilon=1e-8):
    return x / tf.math.sqrt(tf.reduce_mean(x ** 2, axis=-1, keepdims=True) + epsilon)


def minibatch_std(input_tensor, epsilon=1e-8):
    n, h, w, c = tf.shape(input_tensor)
    group_size = tf.minimum(4, n)
    x = tf.reshape(input_tensor, [group_size, -1, h, w, c])
    group_mean, group_var = tf.nn.moments(x, axes=(0), keepdims=False)
    group_std = tf.sqrt(group_var + epsilon)
    avg_std = tf.reduce_mean(group_std, axis=[1, 2, 3], keepdims=True)
    x = tf.tile(avg_std, [group_size, h, w, 1])
    return tf.concat([input_tensor, x], axis=-1)


class EqualizedConv(layers.Layer):
    def __init__(self, out_channels, kernel=3, gain=2, **kwargs):
        super(EqualizedConv, self).__init__(**kwargs)
        self.kernel = kernel
        self.out_channels = out_channels
        self.gain = gain
        self.pad = kernel != 1

    def build(self, input_shape):
        self.in_channels = input_shape[-1]
        initializer = keras.initializers.RandomNormal(mean=0.0, stddev=1.0)
        self.w = self.add_weight(
            shape=[self.kernel, self.kernel, self.in_channels, self.out_channels],
            initializer=initializer,
            trainable=True,
            name="kernel",
        )
        self.b = self.add_weight(
            shape=(self.out_channels,), initializer="zeros", trainable=True, name="bias"
        )
        fan_in = self.kernel * self.kernel * self.in_channels
        self.scale = tf.sqrt(self.gain / fan_in)

    def call(self, inputs):
        if self.pad:
            x = tf.pad(inputs, [[0, 0], [1, 1], [1, 1], [0, 0]], mode="REFLECT")
        else:
            x = inputs
        output = (
            tf.nn.conv2d(x, self.scale * self.w, strides=1, padding="VALID") + self.b
        )
        return output


class EqualizedDense(layers.Layer):
    def __init__(self, units, gain=2, learning_rate_multiplier=1, **kwargs):
        super(EqualizedDense, self).__init__(**kwargs)
        self.units = units
        self.gain = gain
        self.learning_rate_multiplier = learning_rate_multiplier

    def build(self, input_shape):
        self.in_channels = input_shape[-1]
        initializer = keras.initializers.RandomNormal(
            mean=0.0, stddev=1.0 / self.learning_rate_multiplier
        )
        self.w = self.add_weight(
            shape=[self.in_channels, self.units],
            initializer=initializer,
            trainable=True,
            name="kernel",
        )
        self.b = self.add_weight(
            shape=(self.units,), initializer="zeros", trainable=True, name="bias"
        )
        fan_in = self.in_channels
        self.scale = tf.sqrt(self.gain / fan_in)

    def call(self, inputs):
        output = tf.add(tf.matmul(inputs, self.scale * self.w), self.b)
        return output * self.learning_rate_multiplier


class AddNoise(layers.Layer):
    def build(self, input_shape):
        n, h, w, c = input_shape[0]
        initializer = keras.initializers.RandomNormal(mean=0.0, stddev=1.0)
        self.b = self.add_weight(
            shape=[1, 1, 1, c], initializer=initializer, trainable=True, name="kernel"
        )

    def call(self, inputs):
        x, noise = inputs
        output = x + self.b * noise
        return output


class AdaIN(layers.Layer):
    def __init__(self, gain=1, **kwargs):
        super(AdaIN, self).__init__(**kwargs)
        self.gain = gain

    def build(self, input_shapes):
        x_shape = input_shapes[0]
        w_shape = input_shapes[1]

        self.w_channels = w_shape[-1]
        self.x_channels = x_shape[-1]

        self.dense_1 = EqualizedDense(self.x_channels, gain=1)
        self.dense_2 = EqualizedDense(self.x_channels, gain=1)

    def call(self, inputs):
        x, w = inputs
        ys = tf.reshape(self.dense_1(w), (-1, 1, 1, self.x_channels))
        yb = tf.reshape(self.dense_2(w), (-1, 1, 1, self.x_channels))
        return ys * x + yb

def Mapping(num_stages, input_shape=512):
    z = layers.Input(shape=(input_shape))
    w = pixel_norm(z)
    for i in range(8):
        w = EqualizedDense(512, learning_rate_multiplier=0.01)(w)
        w = layers.LeakyReLU(0.2)(w)
    w = tf.tile(tf.expand_dims(w, 1), (1, num_stages, 1))
    return keras.Model(z, w, name="mapping")


class Generator:
    def __init__(self, start_res_log2, target_res_log2):
        self.start_res_log2 = start_res_log2
        self.target_res_log2 = target_res_log2
        self.num_stages = target_res_log2 - start_res_log2 + 1
        # list of generator blocks at increasing resolution
        self.g_blocks = []
        # list of layers to convert g_block activation to RGB
        self.to_rgb = []
        # list of noise input of different resolutions into g_blocks
        self.noise_inputs = []
        # filter size to use at each stage, keys are log2(resolution)
        self.filter_nums = {
            0: 512,
            1: 512,
            2: 512,  # 4x4
            3: 512,  # 8x8
            4: 512,  # 16x16
            5: 512,  # 32x32
            6: 256,  # 64x64
            7: 128,  # 128x128
            8: 64,  # 256x256
            9: 32,  # 512x512
            10: 16,
        }  # 1024x1024

        start_res = 2 ** start_res_log2
        self.input_shape = (start_res, start_res, self.filter_nums[start_res_log2])
        self.g_input = layers.Input(self.input_shape, name="generator_input")

        for i in range(start_res_log2, target_res_log2 + 1):
            filter_num = self.filter_nums[i]
            res = 2 ** i
            self.noise_inputs.append(
                layers.Input(shape=(res, res, 1), name=f"noise_{res}x{res}")
            )
            to_rgb = Sequential(
                [
                    layers.InputLayer(input_shape=(res, res, filter_num)),
                    EqualizedConv(3, 1, gain=1),
                ],
                name=f"to_rgb_{res}x{res}",
            )
            self.to_rgb.append(to_rgb)
            is_base = i == self.start_res_log2
            if is_base:
                input_shape = (res, res, self.filter_nums[i - 1])
            else:
                input_shape = (2 ** (i - 1), 2 ** (i - 1), self.filter_nums[i - 1])
            g_block = self.build_block(
                filter_num, res=res, input_shape=input_shape, is_base=is_base
            )
            self.g_blocks.append(g_block)

    def build_block(self, filter_num, res, input_shape, is_base):
        input_tensor = layers.Input(shape=input_shape, name=f"g_{res}")
        noise = layers.Input(shape=(res, res, 1), name=f"noise_{res}")
        w = layers.Input(shape=512)
        x = input_tensor

        if not is_base:
            x = layers.UpSampling2D((2, 2))(x)
            x = EqualizedConv(filter_num, 3)(x)

        x = AddNoise()([x, noise])
        x = layers.LeakyReLU(0.2)(x)
        x = InstanceNormalization()(x)
        x = AdaIN()([x, w])

        x = EqualizedConv(filter_num, 3)(x)
        x = AddNoise()([x, noise])
        x = layers.LeakyReLU(0.2)(x)
        x = InstanceNormalization()(x)
        x = AdaIN()([x, w])
        return keras.Model([input_tensor, w, noise], x, name=f"genblock_{res}x{res}")

    def grow(self, res_log2):
        res = 2 ** res_log2

        num_stages = res_log2 - self.start_res_log2 + 1
        w = layers.Input(shape=(self.num_stages, 512), name="w")

        alpha = layers.Input(shape=(1), name="g_alpha")
        x = self.g_blocks[0]([self.g_input, w[:, 0], self.noise_inputs[0]])

        if num_stages == 1:
            rgb = self.to_rgb[0](x)
        else:
            for i in range(1, num_stages - 1):

                x = self.g_blocks[i]([x, w[:, i], self.noise_inputs[i]])

            old_rgb = self.to_rgb[num_stages - 2](x)
            old_rgb = layers.UpSampling2D((2, 2))(old_rgb)

            i = num_stages - 1
            x = self.g_blocks[i]([x, w[:, i], self.noise_inputs[i]])

            new_rgb = self.to_rgb[i](x)

            rgb = fade_in(alpha[0], new_rgb, old_rgb)

        return keras.Model(
            [self.g_input, w, self.noise_inputs, alpha],
            rgb,
            name=f"generator_{res}_x_{res}",
        )


class Discriminator:
    def __init__(self, start_res_log2, target_res_log2):
        self.start_res_log2 = start_res_log2
        self.target_res_log2 = target_res_log2
        self.num_stages = target_res_log2 - start_res_log2 + 1
        # filter size to use at each stage, keys are log2(resolution)
        self.filter_nums = {
            0: 512,
            1: 512,
            2: 512,  # 4x4
            3: 512,  # 8x8
            4: 512,  # 16x16
            5: 512,  # 32x32
            6: 256,  # 64x64
            7: 128,  # 128x128
            8: 64,  # 256x256
            9: 32,  # 512x512
            10: 16,
        }  # 1024x1024
        # list of discriminator blocks at increasing resolution
        self.d_blocks = []
        # list of layers to convert RGB into activation for d_blocks inputs
        self.from_rgb = []

        for res_log2 in range(self.start_res_log2, self.target_res_log2 + 1):
            res = 2 ** res_log2
            filter_num = self.filter_nums[res_log2]
            from_rgb = Sequential(
                [
                    layers.InputLayer(
                        input_shape=(res, res, 3), name=f"from_rgb_input_{res}"
                    ),
                    EqualizedConv(filter_num, 1),
                    layers.LeakyReLU(0.2),
                ],
                name=f"from_rgb_{res}",
            )

            self.from_rgb.append(from_rgb)

            input_shape = (res, res, filter_num)
            if len(self.d_blocks) == 0:
                d_block = self.build_base(filter_num, res)
            else:
                d_block = self.build_block(
                    filter_num, self.filter_nums[res_log2 - 1], res
                )

            self.d_blocks.append(d_block)

    def build_base(self, filter_num, res):
        input_tensor = layers.Input(shape=(res, res, filter_num), name=f"d_{res}")
        x = minibatch_std(input_tensor)
        x = EqualizedConv(filter_num, 3)(x)
        x = layers.LeakyReLU(0.2)(x)
        x = layers.Flatten()(x)
        x = EqualizedDense(filter_num)(x)
        x = layers.LeakyReLU(0.2)(x)
        x = EqualizedDense(1)(x)
        return keras.Model(input_tensor, x, name=f"d_{res}")

    def build_block(self, filter_num_1, filter_num_2, res):
        input_tensor = layers.Input(shape=(res, res, filter_num_1), name=f"d_{res}")
        x = EqualizedConv(filter_num_1, 3)(input_tensor)
        x = layers.LeakyReLU(0.2)(x)
        x = EqualizedConv(filter_num_2)(x)
        x = layers.LeakyReLU(0.2)(x)
        x = layers.AveragePooling2D((2, 2))(x)
        return keras.Model(input_tensor, x, name=f"d_{res}")

    def grow(self, res_log2):
        res = 2 ** res_log2
        idx = res_log2 - self.start_res_log2
        alpha = layers.Input(shape=(1), name="d_alpha")
        input_image = layers.Input(shape=(res, res, 3), name="input_image")
        x = self.from_rgb[idx](input_image)
        x = self.d_blocks[idx](x)
        if idx > 0:
            idx -= 1
            downsized_image = layers.AveragePooling2D((2, 2))(input_image)
            y = self.from_rgb[idx](downsized_image)
            x = fade_in(alpha[0], x, y)

            for i in range(idx, -1, -1):
                x = self.d_blocks[i](x)
        return keras.Model([input_image, alpha], x, name=f"discriminator_{res}_x_{res}")

class StyleGAN(tf.keras.Model):
    def __init__(self, z_dim=512, target_res=64, start_res=4):
        super(StyleGAN, self).__init__()
        self.z_dim = z_dim

        self.target_res_log2 = log2(target_res)
        self.start_res_log2 = log2(start_res)
        self.current_res_log2 = self.target_res_log2
        self.num_stages = self.target_res_log2 - self.start_res_log2 + 1

        self.alpha = tf.Variable(1.0, dtype=tf.float32, trainable=False, name="alpha")

        self.mapping = Mapping(num_stages=self.num_stages)
        self.d_builder = Discriminator(self.start_res_log2, self.target_res_log2)
        self.g_builder = Generator(self.start_res_log2, self.target_res_log2)
        self.g_input_shape = self.g_builder.input_shape

        self.phase = None
        self.train_step_counter = tf.Variable(0, dtype=tf.int32, trainable=False)

        self.loss_weights = {"gradient_penalty": 10, "drift": 0.001}

    def grow_model(self, res):
        tf.keras.backend.clear_session()
        res_log2 = log2(res)
        self.generator = self.g_builder.grow(res_log2)
        self.discriminator = self.d_builder.grow(res_log2)
        self.current_res_log2 = res_log2
        print(f"\nModel resolution:{res}x{res}")

    def compile(
        self, steps_per_epoch, phase, res, d_optimizer, g_optimizer, *args, **kwargs
    ):
        self.loss_weights = kwargs.pop("loss_weights", self.loss_weights)
        self.steps_per_epoch = steps_per_epoch
        if res != 2 ** self.current_res_log2:
            self.grow_model(res)
            self.d_optimizer = d_optimizer
            self.g_optimizer = g_optimizer

        self.train_step_counter.assign(0)
        self.phase = phase
        self.d_loss_metric = keras.metrics.Mean(name="d_loss")
        self.g_loss_metric = keras.metrics.Mean(name="g_loss")
        super(StyleGAN, self).compile(*args, **kwargs)

    @property
    def metrics(self):
        return [self.d_loss_metric, self.g_loss_metric]

    def generate_noise(self, batch_size):
        noise = [
            tf.random.normal((batch_size, 2 ** res, 2 ** res, 1))
            for res in range(self.start_res_log2, self.target_res_log2 + 1)
        ]
        return noise

    def gradient_loss(self, grad):
        loss = tf.square(grad)
        loss = tf.reduce_sum(loss, axis=tf.range(1, tf.size(tf.shape(loss))))
        loss = tf.sqrt(loss)
        loss = tf.reduce_mean(tf.square(loss - 1))
        return loss

    def train_step(self, real_images):

        self.train_step_counter.assign_add(1)

        if self.phase == "TRANSITION":
            self.alpha.assign(
                tf.cast(self.train_step_counter / self.steps_per_epoch, tf.float32)
            )
        elif self.phase == "STABLE":
            self.alpha.assign(1.0)
        else:
            raise NotImplementedError
        alpha = tf.expand_dims(self.alpha, 0)
        batch_size = tf.shape(real_images)[0]
        real_labels = tf.ones(batch_size)
        fake_labels = -tf.ones(batch_size)

        z = tf.random.normal((batch_size, self.z_dim))
        const_input = tf.ones(tuple([batch_size] + list(self.g_input_shape)))
        noise = self.generate_noise(batch_size)

        # generator
        with tf.GradientTape() as g_tape:
            w = self.mapping(z)
            fake_images = self.generator([const_input, w, noise, alpha])
            pred_fake = self.discriminator([fake_images, alpha])
            g_loss = wasserstein_loss(real_labels, pred_fake)

            trainable_weights = (
                self.mapping.trainable_weights + self.generator.trainable_weights
            )
            gradients = g_tape.gradient(g_loss, trainable_weights)
            self.g_optimizer.apply_gradients(zip(gradients, trainable_weights))

        # discriminator
        with tf.GradientTape() as gradient_tape, tf.GradientTape() as total_tape:
            # forward pass
            pred_fake = self.discriminator([fake_images, alpha])
            pred_real = self.discriminator([real_images, alpha])

            epsilon = tf.random.uniform((batch_size, 1, 1, 1))
            interpolates = epsilon * real_images + (1 - epsilon) * fake_images
            gradient_tape.watch(interpolates)
            pred_fake_grad = self.discriminator([interpolates, alpha])

            # calculate losses
            loss_fake = wasserstein_loss(fake_labels, pred_fake)
            loss_real = wasserstein_loss(real_labels, pred_real)
            loss_fake_grad = wasserstein_loss(fake_labels, pred_fake_grad)

            # gradient penalty
            gradients_fake = gradient_tape.gradient(loss_fake_grad, [interpolates])
            gradient_penalty = self.loss_weights[
                "gradient_penalty"
            ] * self.gradient_loss(gradients_fake)

            # drift loss
            all_pred = tf.concat([pred_fake, pred_real], axis=0)
            drift_loss = self.loss_weights["drift"] * tf.reduce_mean(all_pred ** 2)

            d_loss = loss_fake + loss_real + gradient_penalty + drift_loss

            gradients = total_tape.gradient(
                d_loss, self.discriminator.trainable_weights
            )
            self.d_optimizer.apply_gradients(
                zip(gradients, self.discriminator.trainable_weights)
            )

        # Update metrics
        self.d_loss_metric.update_state(d_loss)
        self.g_loss_metric.update_state(g_loss)
        return {
            "d_loss": self.d_loss_metric.result(),
            "g_loss": self.g_loss_metric.result(),
        }

    def call(self, inputs: dict()):
        style_code = inputs.get("style_code", None)
        z = inputs.get("z", None)
        noise = inputs.get("noise", None)
        batch_size = inputs.get("batch_size", 1)
        alpha = inputs.get("alpha", 1.0)
        alpha = tf.expand_dims(alpha, 0)
        if style_code is None:
            if z is None:
                z = tf.random.normal((batch_size, self.z_dim))
            style_code = self.mapping(z)

        if noise is None:
            noise = self.generate_noise(batch_size)

        # self.alpha.assign(alpha)

        const_input = tf.ones(tuple([batch_size] + list(self.g_input_shape)))
        images = self.generator([const_input, style_code, noise, alpha])
        images = np.clip((images * 0.5 + 0.5) * 255, 0, 255).astype(np.uint8)

        return images

# Set up GAN

batch_sizes = {2: 16, 3: 16, 4: 16, 5: 16, 6: 16, 7: 8, 8: 4, 9: 2, 10: 1}
train_step_ratio = {k: batch_sizes[2] / v for k, v in batch_sizes.items()}

START_RES = 4
TARGET_RES = 128

# style_gan = StyleGAN(start_res=START_RES, target_res=TARGET_RES)

print("Loading...")

url = "https://github.com/soon-yau/stylegan_keras/releases/download/keras_example_v1.0/stylegan_128x128.ckpt.zip"

weights_path = keras.utils.get_file(
    "stylegan_128x128.ckpt.zip",
    url,
    extract=True,
    cache_dir=os.path.abspath("."),
    cache_subdir="pretrained",
)

# style_gan.grow_model(128)
# style_gan.load_weights(os.path.join("pretrained/stylegan_128x128.ckpt"))

# tf.random.set_seed(196)
# batch_size = 2
# z = tf.random.normal((batch_size, style_gan.z_dim))
# w = style_gan.mapping(z)
# noise = style_gan.generate_noise(batch_size=batch_size)
# images = style_gan({"style_code": w, "noise": noise, "alpha": 1.0})

# plot_images(images, 5)

class InferenceWrapper:
    def __init__(self, model):
        self.model = model
        self.style_gan = StyleGAN(start_res=START_RES, target_res=TARGET_RES)
        self.style_gan.grow_model(128)
        self.style_gan.load_weights(os.path.join("pretrained/stylegan_128x128.ckpt"))
        self.seed = -1

    def __call__(self, seed, feature):
        if seed != self.seed:
            print(f"Loading model: {self.model}")
            tf.random.set_seed(seed)
            batch_size = 1
            self.z = tf.random.normal((batch_size, self.style_gan.z_dim))
            self.w = self.style_gan.mapping(self.z)
            self.noise = self.style_gan.generate_noise(batch_size=batch_size)
        else:
            print(f"Model '{self.model}' already loaded, reusing it.")
        return self.style_gan({"style_code": self.w, "noise": self.noise, "alpha": 1.0})[0]


wrapper = InferenceWrapper('celeba')

def fn(seed, feature):
    return wrapper(seed, feature)

gr.Interface(
    fn,
    inputs=[
        gr.inputs.Slider(minimum=0, maximum=999999999, step=1, default=0, label='Random Seed'),
        gr.inputs.Radio(list({"test1","test2"}), type="value", default='test1', label='Feature Type')
    ],
    outputs='image',
    examples=[[343, 'test1'], [456, 'test2']],
    enable_queue=True,
    title="Keras StyleGAN Generator",
    description="Select random seed and selct Submit to generate a new image",
    article="<p>Face image generation with StyleGAN using tf.keras. The code is from the Keras.io <a class='moflo-link' href='https://keras.io/examples/generative/stylegan/'>exmple</a> by Soon-Yau Cheong</p>",
    css=".panel { padding: 5px } .moflo-link { color: #999 }"
).launch()