3_Transfer_Learning_VGG16.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "educated-thong",
   "metadata": {},
   "outputs": [],
   "source": [
    "import numpy as np\n",
    "import keras\n",
    "import tensorflow as tf\n",
    "from keras_preprocessing.image import ImageDataGenerator\n",
    "from keras.applications.vgg16 import VGG16\n",
    "import time, os, fnmatch, shutil"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "announced-small",
   "metadata": {},
   "outputs": [],
   "source": [
    "cmmd_dir = \"/media/craig/Larry/python/\"\n",
    "\n",
    "train_datagen = ImageDataGenerator(\n",
    "        rescale=1./255,\n",
    "        shear_range=0.2,\n",
    "        zoom_range=0.2,\n",
    "        horizontal_flip=True,\n",
    "        preprocessing_function=tf.keras.applications.vgg16.preprocess_input)\n",
    "test_datagen = ImageDataGenerator(rescale=1./255,\n",
    "                                 preprocessing_function=tf.keras.applications.vgg16.preprocess_input)\n",
    "train_generator = train_datagen.flow_from_directory(\n",
    "        cmmd_dir+\"subset_two/PNG/TRAIN/\",\n",
    "        color_mode='rgb',\n",
    "        target_size=(224, 224),\n",
    "        batch_size=32,\n",
    "        shuffle=True,\n",
    "        class_mode='binary',\n",
    "        seed=11)\n",
    "validation_generator = test_datagen.flow_from_directory(\n",
    "        cmmd_dir+\"subset_two/PNG/VAL/\",\n",
    "        color_mode='rgb',\n",
    "        target_size=(224, 224),\n",
    "        batch_size=32,\n",
    "        shuffle=True,\n",
    "        class_mode='binary',\n",
    "        seed=11)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "established-soviet",
   "metadata": {},
   "source": [
    "# VGG16 Transfer Learning"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "enhanced-palestine",
   "metadata": {},
   "outputs": [],
   "source": [
    "vgg16_base = tf.keras.applications.VGG16(\n",
    "    weights='imagenet',\n",
    "    input_shape=(224, 224, 3),\n",
    "    include_top=False)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "tired-budapest",
   "metadata": {},
   "outputs": [],
   "source": [
    "model = tf.keras.models.Sequential()\n",
    "model.add(vgg16_base)\n",
    "model.add(tf.keras.layers.Flatten())\n",
    "model.add(tf.keras.layers.Dropout(0.5))\n",
    "model.add(tf.keras.layers.Dense(1, activation='sigmoid'))\n",
    "\n",
    "model.layers[0].trainable = False"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "willing-projector",
   "metadata": {},
   "outputs": [],
   "source": [
    "import time, os, fnmatch, shutil\n",
    "root_logdir = os.path.join(os.curdir, \"my_logs\")\n",
    "\n",
    "def get_run_logdir():\n",
    "    #TensorBaoard run TITLE:\n",
    "    run_id = (\"VGG16_Transfer_Learning\")\n",
    "    return os.path.join(root_logdir,run_id)\n",
    "\n",
    "run_logdir = get_run_logdir()\n",
    "tensorboard_cb = keras.callbacks.TensorBoard(run_logdir)\n",
    "\n",
    "callbacks = [\n",
    "    keras.callbacks.ModelCheckpoint(\"/media/craig/Henry/ML_models/vgg16/save_at_{epoch}.h5\"),\n",
    "    keras.callbacks.TensorBoard(run_logdir)\n",
    "]"
   ]
  },
  {
   "cell_type": "raw",
   "id": "looking-hammer",
   "metadata": {},
   "source": [
    "model.compile(\n",
    "    loss='binary_crossentropy',\n",
    "    optimizer=tf.keras.optimizers.Adam(),\n",
    "    metrics=['accuracy']\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "banned-breakdown",
   "metadata": {
    "scrolled": true
   },
   "outputs": [],
   "source": [
    "history = model.fit(\n",
    "    train_generator,\n",
    "    epochs=500,\n",
    "    validation_data=validation_generator,\n",
    "    callbacks=callbacks\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "above-happiness",
   "metadata": {},
   "outputs": [],
   "source": [
    "model.save('/media/craig/Henry/ML_models/vgg16/final_model_epoch_500.h5')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "parallel-glucose",
   "metadata": {},
   "outputs": [],
   "source": [
    "loss_hist = history.history['val_loss']\n",
    "\n",
    "lowest_val_loss = np.min(loss_hist)\n",
    "best_epochs = np.argmin(loss_hist) + 1\n",
    "print(\"The lowest validation loss is: \"+str(lowest_val_loss)+\"\\nAt epoch: \"+str(best_epochs))\n",
    "\n",
    "bin_acc_hist = history.history['val_accuracy']\n",
    "\n",
    "lowest_val_loss = np.max(bin_acc_hist)\n",
    "best_epochs = np.argmax(bin_acc_hist) + 1\n",
    "print(\"The highest validation acc is: \"+str(lowest_val_loss)+\"\\nAt epoch: \"+str(best_epochs))"
   ]
  }
 ],
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