Files
deep-learning-with-python-n…/chapter12_part02_deep-dream.ipynb
2021-06-25 14:03:50 -07:00

245 lines
6.7 KiB
Plaintext

{
"cells": [
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"This is a companion notebook for the book [Deep Learning with Python, Second Edition](https://www.manning.com/books/deep-learning-with-python-second-edition?a_aid=keras&a_bid=76564dff). For readability, it only contains runnable code blocks and section titles, and omits everything else in the book: text paragraphs, figures, and pseudocode.\n\n**If you want to be able to follow what's going on, I recommend reading the notebook side by side with your copy of the book.**\n\nThis notebook was generated for TensorFlow 2.6."
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"## DeepDream"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### Implementing DeepDream in Keras"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"from tensorflow import keras\n",
"import matplotlib.pyplot as plt\n",
"\n",
"base_image_path = keras.utils.get_file(\n",
" \"coast.jpg\", origin=\"https://img-datasets.s3.amazonaws.com/coast.jpg\")\n",
"\n",
"plt.axis(\"off\")\n",
"plt.imshow(keras.utils.load_img(base_image_path))"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"from tensorflow.keras.applications import inception_v3\n",
"model = inception_v3.InceptionV3(weights=\"imagenet\", include_top=False)"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"layer_settings = {\n",
" \"mixed4\": 1.0,\n",
" \"mixed5\": 1.5,\n",
" \"mixed6\": 2.0,\n",
" \"mixed7\": 2.5,\n",
"}\n",
"outputs_dict = dict(\n",
" [\n",
" (layer.name, layer.output)\n",
" for layer in [model.get_layer(name) for name in layer_settings.keys()]\n",
" ]\n",
")\n",
"feature_extractor = keras.Model(inputs=model.inputs, outputs=outputs_dict)"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"def compute_loss(input_image):\n",
" features = feature_extractor(input_image)\n",
" loss = tf.zeros(shape=())\n",
" for name in features.keys():\n",
" coeff = layer_settings[name]\n",
" activation = features[name]\n",
" loss += coeff * tf.reduce_mean(tf.square(activation[:, 2:-2, 2:-2, :]))\n",
" return loss"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"import tensorflow as tf\n",
"\n",
"@tf.function\n",
"def gradient_ascent_step(image, learning_rate):\n",
" with tf.GradientTape() as tape:\n",
" tape.watch(image)\n",
" loss = compute_loss(image)\n",
" grads = tape.gradient(loss, image)\n",
" grads = tf.math.l2_normalize(grads)\n",
" image += learning_rate * grads\n",
" return loss, image\n",
"\n",
"\n",
"def gradient_ascent_loop(image, iterations, learning_rate, max_loss=None):\n",
" for i in range(iterations):\n",
" loss, image = gradient_ascent_step(image, learning_rate)\n",
" if max_loss is not None and loss > max_loss:\n",
" break\n",
" print(f\"... Loss value at step {i}: {loss:.2f}\")\n",
" return image"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"step = 20.\n",
"num_octave = 3\n",
"octave_scale = 1.4\n",
"iterations = 30\n",
"max_loss = 15."
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"import numpy as np\n",
"\n",
"def preprocess_image(image_path):\n",
" img = keras.utils.load_img(image_path)\n",
" img = keras.utils.img_to_array(img)\n",
" img = np.expand_dims(img, axis=0)\n",
" img = keras.applications.inception_v3.preprocess_input(img)\n",
" return img\n",
"\n",
"def deprocess_image(img):\n",
" img = img.reshape((img.shape[1], img.shape[2], 3))\n",
" img /= 2.0\n",
" img += 0.5\n",
" img *= 255.\n",
" img = np.clip(img, 0, 255).astype(\"uint8\")\n",
" return img"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"original_img = preprocess_image(base_image_path)\n",
"original_shape = original_img.shape[1:3]\n",
"\n",
"successive_shapes = [original_shape]\n",
"for i in range(1, num_octave):\n",
" shape = tuple([int(dim / (octave_scale ** i)) for dim in original_shape])\n",
" successive_shapes.append(shape)\n",
"successive_shapes = successive_shapes[::-1]\n",
"\n",
"shrunk_original_img = tf.image.resize(original_img, successive_shapes[0])\n",
"\n",
"img = tf.identity(original_img)\n",
"for i, shape in enumerate(successive_shapes):\n",
" print(f\"Processing octave {i} with shape {shape}\")\n",
" img = tf.image.resize(img, shape)\n",
" img = gradient_ascent_loop(\n",
" img, iterations=iterations, learning_rate=step, max_loss=max_loss\n",
" )\n",
" upscaled_shrunk_original_img = tf.image.resize(shrunk_original_img, shape)\n",
" same_size_original = tf.image.resize(original_img, shape)\n",
" lost_detail = same_size_original - upscaled_shrunk_original_img\n",
" img += lost_detail\n",
" shrunk_original_img = tf.image.resize(original_img, shape)\n",
"\n",
"keras.utils.save_img(\"dream.png\", deprocess_image(img.numpy()))"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### Wrapping up"
]
}
],
"metadata": {
"colab": {
"collapsed_sections": [],
"name": "chapter12_part02_deep-dream.i",
"private_outputs": false,
"provenance": [],
"toc_visible": true
},
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.7.0"
}
},
"nbformat": 4,
"nbformat_minor": 0
}