import cv2
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import numpy as np
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import os
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import sys
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import tensorflow as tf
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from sklearn.model_selection import train_test_split
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EPOCHS = 10
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IMG_WIDTH = 30
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IMG_HEIGHT = 30
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NUM_CATEGORIES = 43
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TEST_SIZE = 0.4
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def main():
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# Check command-line arguments
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if len(sys.argv) not in [2, 3]:
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sys.exit("Usage: python traffic.py data_directory [model.h5]")
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# Get image arrays and labels for all image files
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images, labels = load_data(sys.argv[1])
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# Split data into training and testing sets
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labels = tf.keras.utils.to_categorical(labels)
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x_train, x_test, y_train, y_test = train_test_split(
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np.array(images), np.array(labels), test_size=TEST_SIZE
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)
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# Get a compiled neural network
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model = get_model()
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# Fit model on training data
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model.fit(x_train, y_train, epochs=EPOCHS)
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# Evaluate neural network performance
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model.evaluate(x_test, y_test, verbose=2)
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# Save model to file
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if len(sys.argv) == 3:
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filename = sys.argv[2]
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model.save(filename)
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print(f"Model saved to {filename}.")
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def load_data(data_dir):
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"""
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Load image data from directory `data_dir`.
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Assume `data_dir` has one directory named after each category, numbered
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0 through NUM_CATEGORIES - 1. Inside each category directory will be some
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number of image files.
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Return tuple `(images, labels)`. `images` should be a list of all
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of the images in the data directory, where each image is formatted as a
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numpy ndarray with dimensions IMG_WIDTH x IMG_HEIGHT x 3. `labels` should
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be a list of integer labels, representing the categories for each of the
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corresponding `images`.
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"""
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categories = os.listdir(data_dir)
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labels = []
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images = []
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for i in range(NUM_CATEGORIES):
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imgs = os.listdir(os.path.join(data_dir, str(i)))
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for j in imgs:
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img = cv2.imread(os.path.join(data_dir, str(i), j))
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resized = cv2.resize(img, (int(IMG_WIDTH),int(IMG_HEIGHT)))
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images.append(resized)
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labels.append(i)
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return (images, labels, )
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def get_model():
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"""
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Returns a compiled convolutional neural network model. Assume that the
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`input_shape` of the first layer is `(IMG_WIDTH, IMG_HEIGHT, 3)`.
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The output layer should have `NUM_CATEGORIES` units, one for each category.
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"""
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DROPOUT = 0.5
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CONV_LAYER_SIZE = (5, 5)
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CONV_LAYER_NUM = 32
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POOL_SIZE = (2, 2)
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model = tf.keras.models.Sequential([
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tf.keras.layers.Conv2D(
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CONV_LAYER_NUM, CONV_LAYER_SIZE, activation="relu", input_shape=(IMG_WIDTH, IMG_HEIGHT, 3)
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),
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tf.keras.layers.MaxPooling2D(pool_size=POOL_SIZE),
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tf.keras.layers.Flatten(),
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tf.keras.layers.Dense(64, activation="relu"),
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tf.keras.layers.Dense(32, activation="relu"),
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tf.keras.layers.Dropout(DROPOUT),
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tf.keras.layers.Dense(NUM_CATEGORIES, activation="softmax")
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])
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model.compile(
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optimizer="adam",
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loss="categorical_crossentropy",
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metrics=["accuracy"]
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)
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return model
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if __name__ == "__main__":
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main()
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