Self-Driving Car Engineer Nanodegree

Deep Learning

Project: Build a Traffic Sign Recognition Classifier

In this notebook, a template is provided for you to implement your functionality in stages, which is required to successfully complete this project. If additional code is required that cannot be included in the notebook, be sure that the Python code is successfully imported and included in your submission if necessary.

Note: Once you have completed all of the code implementations, you need to finalize your work by exporting the iPython Notebook as an HTML document. Before exporting the notebook to html, all of the code cells need to have been run so that reviewers can see the final implementation and output. You can then export the notebook by using the menu above and navigating to \n", "File -> Download as -> HTML (.html). Include the finished document along with this notebook as your submission.

In addition to implementing code, there is a writeup to complete. The writeup should be completed in a separate file, which can be either a markdown file or a pdf document. There is a write up template that can be used to guide the writing process. Completing the code template and writeup template will cover all of the rubric points for this project.

The rubric contains "Stand Out Suggestions" for enhancing the project beyond the minimum requirements. The stand out suggestions are optional. If you decide to pursue the "stand out suggestions", you can include the code in this Ipython notebook and also discuss the results in the writeup file.

Note: Code and Markdown cells can be executed using the Shift + Enter keyboard shortcut. In addition, Markdown cells can be edited by typically double-clicking the cell to enter edit mode.


Step 0: Load The Data


In [1]:
# Load pickled data
import pickle

# TODO: Fill this in based on where you saved the training and testing data

training_file = "traffic-signs/train.p"
validation_file= "traffic-signs/valid.p"
testing_file = "traffic-signs/test.p"

with open(training_file, mode='rb') as f:
    train = pickle.load(f)
with open(validation_file, mode='rb') as f:
    valid = pickle.load(f)
with open(testing_file, mode='rb') as f:
    test = pickle.load(f)
    
X_train, y_train = train['features'], train['labels']
X_validation, y_validation = valid['features'], valid['labels']
X_test, y_test = test['features'], test['labels']

Step 1: Dataset Summary & Exploration

The pickled data is a dictionary with 4 key/value pairs:

  • 'features' is a 4D array containing raw pixel data of the traffic sign images, (num examples, width, height, channels).
  • 'labels' is a 1D array containing the label/class id of the traffic sign. The file signnames.csv contains id -> name mappings for each id.
  • 'sizes' is a list containing tuples, (width, height) representing the original width and height the image.
  • 'coords' is a list containing tuples, (x1, y1, x2, y2) representing coordinates of a bounding box around the sign in the image. THESE COORDINATES ASSUME THE ORIGINAL IMAGE. THE PICKLED DATA CONTAINS RESIZED VERSIONS (32 by 32) OF THESE IMAGES

Complete the basic data summary below. Use python, numpy and/or pandas methods to calculate the data summary rather than hard coding the results. For example, the pandas shape method might be useful for calculating some of the summary results.

Provide a Basic Summary of the Data Set Using Python, Numpy and/or Pandas


In [2]:
# Basic Summary and Data Set info
import numpy as np
import matplotlib.pyplot as plt
import csv

# TODO: Number of training / validation / testing examples
n_train = X_train.shape[0]
n_validation = X_validation.shape[0]
n_test = X_test.shape[0]

# TODO: What's the shape of an traffic sign image?
image_shape = X_train[0].shape
image_shape_v = X_validation[0].shape
image_shape_t = X_test[0].shape

# TODO: How many unique classes/labels there are in the dataset.
n_classes = np.unique(y_train).shape[0]
n_classes_v = np.unique(y_validation).shape[0]
n_classes_t = np.unique(y_test).shape[0]

class_list = []
with open('signnames.csv') as csvfile:
    reader = csv.DictReader(csvfile)
    for row in reader:
        class_list.append(row['SignName'])

n_classes_csv = len(class_list)
        
print("Number of training examples =", n_train)
print("Number of validation examples =", n_validation)
print("Number of testing examples =", n_test)
print("Image Shape:")
print("      train dataset = ", image_shape)
print("      validation dataset = ", image_shape_v)
print("      test dataset = ", image_shape_t)
print("Number of classes:")
print("      distinct labels in train dataset = ", n_classes)
print("      distinct labels in validation dataset = ", n_classes_v)
print("      distinct labels in test dataset = ", n_classes_t)
print("      labels in csv = ", n_classes_csv)


Number of training examples = 34799
Number of validation examples = 4410
Number of testing examples = 12630
Image Shape:
      train dataset =  (32, 32, 3)
      validation dataset =  (32, 32, 3)
      test dataset =  (32, 32, 3)
Number of classes:
      distinct labels in train dataset =  43
      distinct labels in validation dataset =  43
      distinct labels in test dataset =  43
      labels in csv =  43

Include an exploratory visualization of the dataset

Visualize the German Traffic Signs Dataset using the pickled file(s). This is open ended, suggestions include: plotting traffic sign images, plotting the count of each sign, etc.

The Matplotlib examples and gallery pages are a great resource for doing visualizations in Python.

NOTE: It's recommended you start with something simple first. If you wish to do more, come back to it after you've completed the rest of the sections. It can be interesting to look at the distribution of classes in the training, validation and test set. Is the distribution the same? Are there more examples of some classes than others?


In [3]:
print(" ")
print("Training samples distribution per class")

n_samples=[]    
for i in range(0, n_classes):
    n_samples.append(X_train[y_train == i].shape[0])
    
class_list = np.asarray(list(zip(class_list, n_samples)))

plt.figure(figsize=(10, 2))
plt.bar(range(0, n_classes), n_samples,color='blue',edgecolor='black')
plt.title("Training samples per class")
plt.xlabel("Id")
plt.ylabel("Number of samples")
plt.show()

print(" ")
print("Validation samples distribution per class")

n_samples=[]    
for i in range(0, n_classes_v):
    n_samples.append(X_validation[y_validation == i].shape[0])

plt.figure(figsize=(10, 2))
plt.bar(range(0, n_classes), n_samples,color='blue',edgecolor='black')
plt.title("Validation samples per class")
plt.xlabel("Id")
plt.ylabel("Number of samples")
plt.show()

print(" ")
print("Testing samples distribution per class")

n_samples=[]    
for i in range(0, n_classes_t):
    n_samples.append(X_test[y_test == i].shape[0])

plt.figure(figsize=(10, 2))
plt.bar(range(0, n_classes), n_samples,color='blue',edgecolor='black')
plt.title("Testing samples per class")
plt.xlabel("Id")
plt.ylabel("Number of samples")
plt.show()


 
Training samples distribution per class
 
Validation samples distribution per class
 
Testing samples distribution per class

Select one train image:


In [4]:
### German sign images are already 32x32
import cv2
import random

# Visualizations will be shown in the notebook.
%matplotlib inline

n_classes_csv = len(class_list)
n_samples=[]    
for i in range(0, n_classes):
    n_samples.append(X_train[y_train == i].shape[0])
    
class_list = np.asarray(list(zip(class_list, n_samples)))

index = random.randint(0, len(X_train))
image = X_train[index].squeeze()

plt.figure(figsize=(1,1))
plt.imshow(image)
print("Classifier ID = ", y_train[index], ", Description = ", class_list[y_train[index],0])


Classifier ID =  7 , Description =  ['Speed limit (100km/h)' '1290']

Step 2: Design and Test a Model Architecture

Design and implement a deep learning model that learns to recognize traffic signs. Train and test your model on the German Traffic Sign Dataset.

The LeNet-5 implementation shown in the classroom at the end of the CNN lesson is a solid starting point. You'll have to change the number of classes and possibly the preprocessing, but aside from that it's plug and play!

With the LeNet-5 solution from the lecture, you should expect a validation set accuracy of about 0.89. To meet specifications, the validation set accuracy will need to be at least 0.93. It is possible to get an even higher accuracy, but 0.93 is the minimum for a successful project submission.

There are various aspects to consider when thinking about this problem:

  • Neural network architecture (is the network over or underfitting?)
  • Play around preprocessing techniques (normalization, rgb to grayscale, etc)
  • Number of examples per label (some have more than others).
  • Generate fake data.

Here is an example of a published baseline model on this problem. It's not required to be familiar with the approach used in the paper but, it's good practice to try to read papers like these.

Pre-process the Data Set (normalization, grayscale, etc.)

Minimally, the image data should be normalized so that the data has mean zero and equal variance. For image data, (pixel - 128)/ 128 is a quick way to approximately normalize the data and can be used in this project.

Other pre-processing steps are optional. You can try different techniques to see if it improves performance.

Use the code cell (or multiple code cells, if necessary) to implement the first step of your project.


In [5]:
def perform_grayscale(image):
    return cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)

def perform_hist_equalization(grayscale_image):
    return cv2.equalizeHist(grayscale_image)
    
def perform_image_normalization(equalized_image):
    return equalized_image/255.-.5

def pre_process_image(image):
    image = perform_grayscale(image)
    image = perform_hist_equalization(image)
    image = perform_image_normalization(image)
    return np.expand_dims(image,axis=3)

In [6]:
original_image = X_train[index].squeeze()
grayscale_image = perform_grayscale(original_image)
equalized_image = perform_hist_equalization(grayscale_image)
normalized_image = perform_image_normalization(equalized_image)
image_shape = np.shape(normalized_image)

print("Original image:")
plt.figure(figsize=(1,1))
plt.imshow(original_image)
print(y_train[index])
plt.show()
print("Grayscale image data shape =", image_shape)

print("Preprocess Image techiniques applied")
print("Converted to grayscale")
plt.figure(figsize=(1,1))
plt.imshow(grayscale_image, cmap='gray')
plt.show()

print("Converted to grayscale + histogram equalization:")
plt.figure(figsize=(1,1))
plt.imshow(equalized_image, cmap='gray')
plt.show()

print("Converted to grayscale + histogram equalization + normalization:")
plt.figure(figsize=(1,1))
plt.imshow(normalized_image, cmap='gray')
plt.show()

new_image = pre_process_image(image)
new_image_shape = np.shape(new_image)
print("New Image data shape =", new_image_shape)


Original image:
7
Grayscale image data shape = (32, 32)
Preprocess Image techiniques applied
Converted to grayscale
Converted to grayscale + histogram equalization:
Converted to grayscale + histogram equalization + normalization:
New Image data shape = (32, 32, 1)

Changing training data


In [7]:
import cv2

img_resize = 32
N_classes = 43
image_shape = (img_resize,img_resize)
img_size_flat = img_resize*img_resize


image_S_train = np.array([pre_process_image(X_train[i]) for i in range(len(X_train))],
                          dtype = np.float32)

image_S_valid = np.array([pre_process_image(X_validation[i]) for i in range(len(X_validation))],
                          dtype = np.float32)

image_S_test = np.array([pre_process_image(X_test[i]) for i in range(len(X_test))],
                          dtype = np.float32)

In [8]:
### Shuffle the training data.
from sklearn.utils import shuffle

image_S_train, y_train = shuffle(image_S_train, y_train)

Setup TensorFlow

The EPOCH and BATCH_SIZE values affect the training speed and model accuracy.

You do not need to modify this section.


In [9]:
import tensorflow as tf

EPOCHS = 80
BATCH_SIZE = 128

Model Architecture

Using LeNet-5 based architecture

Implement the LeNet-5 neural network architecture.

Input

The LeNet architecture accepts a 32x32xC image as input, where C is the number of color channels. Since German sign images are 32x32 RGB, C is 3 in this case.

Architecture

Layer 1: Convolutional. The output shape should be 28x28x6.

Activation. Your choice of activation function.

Pooling. The output shape should be 14x14x6.

Layer 2: Convolutional. The output shape should be 10x10x16.

Activation. Your choice of activation function.

Pooling. The output shape should be 5x5x16.

Flatten. Flatten the output shape of the final pooling layer such that it's 1D instead of 3D. The easiest way to do is by using tf.contrib.layers.flatten, which is already imported for you.

Layer 3: Fully Connected. This should have 120 outputs.

Activation. Your choice of activation function.

Layer 4: Fully Connected. This should have 84 outputs.

Activation. Your choice of activation function.

Layer 5: Fully Connected (Logits). This should have 43 outputs.

Output

Return the result of the 2nd fully connected layer.


In [10]:
from tensorflow.contrib.layers import flatten
n_channels = 1

def dropout_layer(layer, keep_prob):
    layer_drop = tf.nn.dropout(layer, keep_prob)
    return layer_drop

def LeNet(x):    
    # Arguments used for tf.truncated_normal, randomly defines variables for the weights and biases for each layer
    keep_prob = 0.75
    mu = 0
    sigma = 0.1
    
    # SOLUTION: Layer 1: Convolutional. Input = 32x32x1. Output = 28x28x12. 3 inputs colour channels
    conv1_W = tf.Variable(tf.truncated_normal(shape=(5, 5, n_channels, 12), mean = mu, stddev = sigma))
    conv1_b = tf.Variable(tf.zeros(12))
    conv1   = tf.nn.conv2d(x, conv1_W, strides=[1, 1, 1, 1], padding='VALID') + conv1_b

    # SOLUTION: Activation.
    conv1 = tf.nn.relu(conv1)

    # SOLUTION: Pooling. Input = 28x28x12. Output = 14x14x12.
    conv1 = tf.nn.max_pool(conv1, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='VALID')
    
    #layer_conv1_drop = dropout_layer(conv1, 0.5)

    # SOLUTION: Layer 2: Convolutional. Output = 10x10x32.
    conv2_W = tf.Variable(tf.truncated_normal(shape=(5, 5, 12, 32), mean = mu, stddev = sigma))
    conv2_b = tf.Variable(tf.zeros(32))
    conv2   = tf.nn.conv2d(conv1, conv2_W, strides=[1, 1, 1, 1], padding='VALID') + conv2_b
    
    # SOLUTION: Activation.
    conv2 = tf.nn.relu(conv2)

    # SOLUTION: Pooling. Input = 10x10x32. Output = 5x5x32.
    conv2 = tf.nn.max_pool(conv2, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='VALID')
    
    # TODO: Layer 2-b: Convolutional. Input = 5x5x32. Output = 3x3x64. 
    conv3_W = tf.Variable(tf.truncated_normal(shape=(3, 3, 32, 64), mean = mu, stddev = sigma))
    conv3_b = tf.Variable(tf.zeros(64))
    conv3   = tf.nn.conv2d(conv2, conv3_W, strides=[1, 1, 1, 1], padding='VALID') + conv3_b
    # TODO: Activation.
    conv3 = tf.nn.relu(conv3)

    # SOLUTION: Flatten. Input = 3x3x64. Output = 800.
    fc0   = flatten(conv2)
    fc0   = tf.nn.dropout(fc0, keep_prob)
    
    # SOLUTION: Layer 3: Fully Connected. Input = 800. Output = 256.
    fc1_W = tf.Variable(tf.truncated_normal(shape=(800, 256), mean = mu, stddev = sigma))
    fc1_b = tf.Variable(tf.zeros(256))
    fc1   = tf.matmul(fc0, fc1_W) + fc1_b
    
    # SOLUTION: Activation.
    fc1    = tf.nn.relu(fc1)
    fc1   = tf.nn.dropout(fc1, keep_prob) 

    # SOLUTION: Layer 4: Fully Connected. Input = 120. Output = 84.
    fc2_W  = tf.Variable(tf.truncated_normal(shape=(256, 84), mean = mu, stddev = sigma))
    fc2_b  = tf.Variable(tf.zeros(84))
    fc2    = tf.matmul(fc1, fc2_W) + fc2_b
    
    # SOLUTION: Activation.
    fc2    = tf.nn.relu(fc2)

    # SOLUTION: Layer 5: Fully Connected. Input = 84. Output = 43.
    fc3_W  = tf.Variable(tf.truncated_normal(shape=(84, 43), mean = mu, stddev = sigma))
    fc3_b  = tf.Variable(tf.zeros(43))
    logits = tf.matmul(fc2, fc3_W) + fc3_b
    
    return logits, conv1, conv2, conv3

Features and Labels

Train LeNet to classify the German signs.

x is a placeholder for a batch of input images. y is a placeholder for a batch of output labels.

You do not need to modify this section.


In [11]:
x = tf.placeholder(tf.float32, (None, 32, 32, n_channels))
y = tf.placeholder(tf.int32, (None))
one_hot_y = tf.one_hot(y, 43)
keep_prob = tf.placeholder(tf.float32)

Training Pipeline

Create a training pipeline that uses the model to classify German sign images.


In [12]:
rate = 0.0005

logits, conv1, conv2, conv3 = LeNet(x)
cross_entropy = tf.nn.softmax_cross_entropy_with_logits(labels=one_hot_y, logits=logits)
loss_operation = tf.reduce_mean(cross_entropy)
optimizer = tf.train.AdamOptimizer(learning_rate = rate)
training_operation = optimizer.minimize(loss_operation)

Model Evaluation

Evaluate how well the loss and accuracy of the model for a given dataset.

You do not need to modify this section.


In [13]:
correct_prediction = tf.equal(tf.argmax(logits, 1), tf.argmax(one_hot_y, 1))
accuracy_operation = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))
saver = tf.train.Saver()

def evaluate(X_data, y_data):
    num_examples = len(X_data)
    total_accuracy = 0.0
    sess = tf.get_default_session()
    for offset in range(0, num_examples, BATCH_SIZE):
        batch_x, batch_y = X_data[offset:offset+BATCH_SIZE], y_data[offset:offset+BATCH_SIZE]
        accuracy = sess.run(accuracy_operation, feed_dict={x: batch_x, y: batch_y, keep_prob: 1.0})
        total_accuracy += (accuracy * len(batch_x))
    return total_accuracy / num_examples

Train, Validate and Test the Model

A validation set can be used to assess how well the model is performing. A low accuracy on the training and validation sets imply underfitting. A high accuracy on the training set but low accuracy on the validation set implies overfitting.

Train the Model

Run the training data through the training pipeline to train the model.

Before each epoch, shuffle the training set.

After each epoch, measure the loss and accuracy of the validation set.

Save the model after training.

You do not need to modify this section.


In [14]:
with tf.Session() as sess:
    sess.run(tf.global_variables_initializer())
    num_examples = len(image_S_train)
    
    print("Training...")
    print()
    val_accu_list = []
    batch_acc_list = []
    for i in range(EPOCHS):
#         X_train, y_train = shuffle(X_train, y_train)
        for offset in range(0, num_examples, BATCH_SIZE):
            end = offset + BATCH_SIZE
            batch_x, batch_y = image_S_train[offset:end], y_train[offset:end]
            sess.run(training_operation, feed_dict={x: batch_x, y: batch_y})
            
        training_accuracy = evaluate(image_S_train, y_train)
        validation_accuracy = evaluate(image_S_valid, y_validation)
        batch_accuracy = evaluate(batch_x, batch_y)
        val_accu_list.append(validation_accuracy)
        batch_acc_list.append(batch_accuracy)
        print("EPOCH {} ...".format(i+1))
        print("Training Accuracy = {:.3f}".format(training_accuracy))
        print("Validation Accuracy = {:.3f}".format(validation_accuracy))
        print()
        
    saver.save(sess, './traffic_classifier_data')
    print("Model saved")


Training...

EPOCH 1 ...
Training Accuracy = 0.712
Validation Accuracy = 0.685

EPOCH 2 ...
Training Accuracy = 0.849
Validation Accuracy = 0.807

EPOCH 3 ...
Training Accuracy = 0.902
Validation Accuracy = 0.852

EPOCH 4 ...
Training Accuracy = 0.930
Validation Accuracy = 0.884

EPOCH 5 ...
Training Accuracy = 0.943
Validation Accuracy = 0.892

EPOCH 6 ...
Training Accuracy = 0.957
Validation Accuracy = 0.910

EPOCH 7 ...
Training Accuracy = 0.961
Validation Accuracy = 0.911

EPOCH 8 ...
Training Accuracy = 0.965
Validation Accuracy = 0.921

EPOCH 9 ...
Training Accuracy = 0.971
Validation Accuracy = 0.923

EPOCH 10 ...
Training Accuracy = 0.974
Validation Accuracy = 0.922

EPOCH 11 ...
Training Accuracy = 0.979
Validation Accuracy = 0.930

EPOCH 12 ...
Training Accuracy = 0.978
Validation Accuracy = 0.926

EPOCH 13 ...
Training Accuracy = 0.982
Validation Accuracy = 0.933

EPOCH 14 ...
Training Accuracy = 0.983
Validation Accuracy = 0.931

EPOCH 15 ...
Training Accuracy = 0.986
Validation Accuracy = 0.934

EPOCH 16 ...
Training Accuracy = 0.986
Validation Accuracy = 0.929

EPOCH 17 ...
Training Accuracy = 0.988
Validation Accuracy = 0.938

EPOCH 18 ...
Training Accuracy = 0.987
Validation Accuracy = 0.936

EPOCH 19 ...
Training Accuracy = 0.990
Validation Accuracy = 0.939

EPOCH 20 ...
Training Accuracy = 0.990
Validation Accuracy = 0.943

EPOCH 21 ...
Training Accuracy = 0.989
Validation Accuracy = 0.944

EPOCH 22 ...
Training Accuracy = 0.991
Validation Accuracy = 0.940

EPOCH 23 ...
Training Accuracy = 0.991
Validation Accuracy = 0.941

EPOCH 24 ...
Training Accuracy = 0.989
Validation Accuracy = 0.944

EPOCH 25 ...
Training Accuracy = 0.990
Validation Accuracy = 0.939

EPOCH 26 ...
Training Accuracy = 0.993
Validation Accuracy = 0.941

EPOCH 27 ...
Training Accuracy = 0.993
Validation Accuracy = 0.942

EPOCH 28 ...
Training Accuracy = 0.993
Validation Accuracy = 0.943

EPOCH 29 ...
Training Accuracy = 0.993
Validation Accuracy = 0.944

EPOCH 30 ...
Training Accuracy = 0.992
Validation Accuracy = 0.950

EPOCH 31 ...
Training Accuracy = 0.992
Validation Accuracy = 0.951

EPOCH 32 ...
Training Accuracy = 0.994
Validation Accuracy = 0.941

EPOCH 33 ...
Training Accuracy = 0.995
Validation Accuracy = 0.945

EPOCH 34 ...
Training Accuracy = 0.994
Validation Accuracy = 0.945

EPOCH 35 ...
Training Accuracy = 0.995
Validation Accuracy = 0.954

EPOCH 36 ...
Training Accuracy = 0.996
Validation Accuracy = 0.947

EPOCH 37 ...
Training Accuracy = 0.996
Validation Accuracy = 0.949

EPOCH 38 ...
Training Accuracy = 0.994
Validation Accuracy = 0.949

EPOCH 39 ...
Training Accuracy = 0.996
Validation Accuracy = 0.952

EPOCH 40 ...
Training Accuracy = 0.995
Validation Accuracy = 0.948

EPOCH 41 ...
Training Accuracy = 0.996
Validation Accuracy = 0.949

EPOCH 42 ...
Training Accuracy = 0.995
Validation Accuracy = 0.946

EPOCH 43 ...
Training Accuracy = 0.996
Validation Accuracy = 0.951

EPOCH 44 ...
Training Accuracy = 0.995
Validation Accuracy = 0.951

EPOCH 45 ...
Training Accuracy = 0.997
Validation Accuracy = 0.952

EPOCH 46 ...
Training Accuracy = 0.995
Validation Accuracy = 0.946

EPOCH 47 ...
Training Accuracy = 0.996
Validation Accuracy = 0.949

EPOCH 48 ...
Training Accuracy = 0.997
Validation Accuracy = 0.953

EPOCH 49 ...
Training Accuracy = 0.996
Validation Accuracy = 0.951

EPOCH 50 ...
Training Accuracy = 0.997
Validation Accuracy = 0.950

EPOCH 51 ...
Training Accuracy = 0.996
Validation Accuracy = 0.955

EPOCH 52 ...
Training Accuracy = 0.996
Validation Accuracy = 0.954

EPOCH 53 ...
Training Accuracy = 0.996
Validation Accuracy = 0.946

EPOCH 54 ...
Training Accuracy = 0.997
Validation Accuracy = 0.945

EPOCH 55 ...
Training Accuracy = 0.996
Validation Accuracy = 0.952

EPOCH 56 ...
Training Accuracy = 0.997
Validation Accuracy = 0.955

EPOCH 57 ...
Training Accuracy = 0.996
Validation Accuracy = 0.951

EPOCH 58 ...
Training Accuracy = 0.997
Validation Accuracy = 0.948

EPOCH 59 ...
Training Accuracy = 0.997
Validation Accuracy = 0.954

EPOCH 60 ...
Training Accuracy = 0.998
Validation Accuracy = 0.961

EPOCH 61 ...
Training Accuracy = 0.997
Validation Accuracy = 0.949

EPOCH 62 ...
Training Accuracy = 0.996
Validation Accuracy = 0.958

EPOCH 63 ...
Training Accuracy = 0.997
Validation Accuracy = 0.956

EPOCH 64 ...
Training Accuracy = 0.997
Validation Accuracy = 0.956

EPOCH 65 ...
Training Accuracy = 0.997
Validation Accuracy = 0.958

EPOCH 66 ...
Training Accuracy = 0.998
Validation Accuracy = 0.954

EPOCH 67 ...
Training Accuracy = 0.998
Validation Accuracy = 0.952

EPOCH 68 ...
Training Accuracy = 0.996
Validation Accuracy = 0.949

EPOCH 69 ...
Training Accuracy = 0.997
Validation Accuracy = 0.958

EPOCH 70 ...
Training Accuracy = 0.997
Validation Accuracy = 0.956

EPOCH 71 ...
Training Accuracy = 0.998
Validation Accuracy = 0.960

EPOCH 72 ...
Training Accuracy = 0.997
Validation Accuracy = 0.954

EPOCH 73 ...
Training Accuracy = 0.998
Validation Accuracy = 0.956

EPOCH 74 ...
Training Accuracy = 0.998
Validation Accuracy = 0.955

EPOCH 75 ...
Training Accuracy = 0.997
Validation Accuracy = 0.950

EPOCH 76 ...
Training Accuracy = 0.997
Validation Accuracy = 0.960

EPOCH 77 ...
Training Accuracy = 0.997
Validation Accuracy = 0.958

EPOCH 78 ...
Training Accuracy = 0.998
Validation Accuracy = 0.949

EPOCH 79 ...
Training Accuracy = 0.996
Validation Accuracy = 0.954

EPOCH 80 ...
Training Accuracy = 0.998
Validation Accuracy = 0.959

Model saved

Plot data


In [15]:
plt.plot(batch_acc_list, label="Train Accuracy")
plt.plot(val_accu_list, label="Validation Accuracy")
plt.ylim(.4,1.1)
plt.xlim(0,EPOCHS)


Out[15]:
(0, 80)

Evaluate the Model

Once you are completely satisfied with your model, evaluate the performance of the model on the test set.

Be sure to only do this once!

If you were to measure the performance of your trained model on the test set, then improve your model, and then measure the performance of your model on the test set again, that would invalidate your test results. You wouldn't get a true measure of how well your model would perform against real data.

You do not need to modify this section.


In [16]:
with tf.Session() as sess:
    saver.restore(sess, tf.train.latest_checkpoint('.'))

    test_accuracy = evaluate(image_S_test, y_test)
    print("Test Accuracy = {:.3f}".format(test_accuracy))


Test Accuracy = 0.937

Step 3: Test a Model on New Images

To give yourself more insight into how your model is working, download at least five pictures of German traffic signs from the web and use your model to predict the traffic sign type.

You may find signnames.csv useful as it contains mappings from the class id (integer) to the actual sign name.

Load and Output the Images


In [17]:
### Load the images and plot them here.
### Feel free to use as many code cells as needed.
import os
import cv2
import matplotlib.pyplot as plt

new_images_original = []
test_image_labels = list()
test_image_labels.append(27)
test_image_labels.append(25)
test_image_labels.append(14)
test_image_labels.append(33)
test_image_labels.append(13)

path = "new_images/"
files = sorted(os.listdir(path))
print("Original images:")
i = 0
for file in files:
    print(path+file)
    image = cv2.imread(path+file)
    image = image[...,::-1] # Convert from BGR <=> RGB
    resized_image = cv2.resize(image,(32,32))
    new_images_original.append(resized_image)
    label = test_image_labels[i]
    desc = class_list[[label],0]
    print("Label = ", label, ". Desc = ", desc)
    i += 1
    
    plt.figure(figsize=(1, 1))
    plt.imshow(image)
    plt.show()

print(test_image_labels)


Original images:
new_images/pedestrians.jpg
Label =  27 . Desc =  [array(['Pedestrians', '210'], 
      dtype='<U50')]
new_images/road_work.jpg
Label =  25 . Desc =  [array(['Road work', '1350'], 
      dtype='<U50')]
new_images/stop.jpg
Label =  14 . Desc =  [array(['Stop', '690'], 
      dtype='<U50')]
new_images/turn_right_ahead.jpg
Label =  33 . Desc =  [array(['Turn right ahead', '599'], 
      dtype='<U50')]
new_images/yield.jpg
Label =  13 . Desc =  [array(['Yield', '1920'], 
      dtype='<U50')]
[27, 25, 14, 33, 13]

In [18]:
test_images = []

print("Preprocessed images:")
for image in new_images_original:
    preprocessed_image = pre_process_image(image)
    test_images.append(preprocessed_image)
    plt.figure(figsize=(1, 1))
    plt.imshow(preprocessed_image[:,:,0], cmap='gray')
    plt.show()


Preprocessed images:

Predict the Sign Type for Each Image


In [19]:
### Run the predictions here and use the model to output the prediction for each image.
### Make sure to pre-process the images with the same pre-processing pipeline used earlier.
### Feel free to use as many code cells as needed.

with tf.Session() as sess:
    saver.restore(sess, './traffic_classifier_data')
    top5_prob = sess.run(tf.nn.top_k(tf.nn.softmax(logits), k=5, sorted=True), feed_dict = {x: test_images, keep_prob:1})
#     predicted_logits = sess.run(logits, feed_dict={x:test_images, keep_prob:1})
#     predicts = sess.run(tf.nn.top_k(top5_prob, k=5, sorted=True))
    predicted_labels = np.argmax(top5_prob, axis=1)
#     predictions_labels = np.argmax(predictions, axis=1)
i=0
for image in test_images:
    plt.figure(figsize=(1, 1))
    print("Index=", top5_prob.indices[i, 0])
    plt.xlabel(class_list[top5_prob.indices[i, 0],0])
    plt.imshow(image[:,:,0], cmap='gray')
    plt.show()
    i += 1


Index= 37
Index= 25
Index= 14
Index= 33
Index= 13

Analyze Performance


In [20]:
### Calculate the accuracy for these 5 new images. 
### For example, if the model predicted 1 out of 5 signs correctly, it's 20% accurate on these new images.

with tf.Session() as sess:
    saver.restore(sess, tf.train.latest_checkpoint('.'))

    test_accuracy = evaluate(test_images, test_image_labels)
    print("Test Accuracy = {:.2f}".format(test_accuracy))


Test Accuracy = 0.80

Output Top 5 Softmax Probabilities For Each Image Found on the Web

For each of the new images, print out the model's softmax probabilities to show the certainty of the model's predictions (limit the output to the top 5 probabilities for each image). tf.nn.top_k could prove helpful here.

The example below demonstrates how tf.nn.top_k can be used to find the top k predictions for each image.

tf.nn.top_k will return the values and indices (class ids) of the top k predictions. So if k=3, for each sign, it'll return the 3 largest probabilities (out of a possible 43) and the correspoding class ids.

Take this numpy array as an example. The values in the array represent predictions. The array contains softmax probabilities for five candidate images with six possible classes. tf.nn.top_k is used to choose the three classes with the highest probability:

# (5, 6) array
a = np.array([[ 0.24879643,  0.07032244,  0.12641572,  0.34763842,  0.07893497,
         0.12789202],
       [ 0.28086119,  0.27569815,  0.08594638,  0.0178669 ,  0.18063401,
         0.15899337],
       [ 0.26076848,  0.23664738,  0.08020603,  0.07001922,  0.1134371 ,
         0.23892179],
       [ 0.11943333,  0.29198961,  0.02605103,  0.26234032,  0.1351348 ,
         0.16505091],
       [ 0.09561176,  0.34396535,  0.0643941 ,  0.16240774,  0.24206137,
         0.09155967]])

Running it through sess.run(tf.nn.top_k(tf.constant(a), k=3)) produces:

TopKV2(values=array([[ 0.34763842,  0.24879643,  0.12789202],
       [ 0.28086119,  0.27569815,  0.18063401],
       [ 0.26076848,  0.23892179,  0.23664738],
       [ 0.29198961,  0.26234032,  0.16505091],
       [ 0.34396535,  0.24206137,  0.16240774]]), indices=array([[3, 0, 5],
       [0, 1, 4],
       [0, 5, 1],
       [1, 3, 5],
       [1, 4, 3]], dtype=int32))

Looking just at the first row we get [ 0.34763842, 0.24879643, 0.12789202], you can confirm these are the 3 largest probabilities in a. You'll also notice [3, 0, 5] are the corresponding indices.


In [21]:
### Print out the top five softmax probabilities for the predictions on the German traffic sign images found on the web. 
### Feel free to use as many code cells as needed.
test_images = np.asarray(test_images)
print(test_images.shape)

plt.figure(figsize=(16, 21))
for i in range(5):
    plt.subplot(12, 2, 2*i+1)
    plt.imshow(test_images[i][:,:,0], cmap="gray") 
    plt.axis('off')
    plt.title(i)
    plt.subplot(12, 2, 2*i+2)
    plt.axis([0, 1., 0, 6])
    plt.barh(np.arange(1, 6, 1), (np.absolute(top5_prob.values[i, :]/sum(np.absolute(top5_prob.values[i, :])))))
    labs=[class_list[j][0] for j in top5_prob.indices[i, :]]
    plt.yticks(np.arange(1, 6, 1), labs)
plt.show()


(5, 32, 32, 1)

Project Writeup

Once you have completed the code implementation, document your results in a project writeup using this template as a guide. The writeup can be in a markdown or pdf file.

Note: Once you have completed all of the code implementations and successfully answered each question above, you may finalize your work by exporting the iPython Notebook as an HTML document. You can do this by using the menu above and navigating to \n", "File -> Download as -> HTML (.html). Include the finished document along with this notebook as your submission.


Step 4 (Optional): Visualize the Neural Network's State with Test Images

This Section is not required to complete but acts as an additional excersise for understaning the output of a neural network's weights. While neural networks can be a great learning device they are often referred to as a black box. We can understand what the weights of a neural network look like better by plotting their feature maps. After successfully training your neural network you can see what it's feature maps look like by plotting the output of the network's weight layers in response to a test stimuli image. From these plotted feature maps, it's possible to see what characteristics of an image the network finds interesting. For a sign, maybe the inner network feature maps react with high activation to the sign's boundary outline or to the contrast in the sign's painted symbol.

Provided for you below is the function code that allows you to get the visualization output of any tensorflow weight layer you want. The inputs to the function should be a stimuli image, one used during training or a new one you provided, and then the tensorflow variable name that represents the layer's state during the training process, for instance if you wanted to see what the LeNet lab's feature maps looked like for it's second convolutional layer you could enter conv2 as the tf_activation variable.

For an example of what feature map outputs look like, check out NVIDIA's results in their paper End-to-End Deep Learning for Self-Driving Cars in the section Visualization of internal CNN State. NVIDIA was able to show that their network's inner weights had high activations to road boundary lines by comparing feature maps from an image with a clear path to one without. Try experimenting with a similar test to show that your trained network's weights are looking for interesting features, whether it's looking at differences in feature maps from images with or without a sign, or even what feature maps look like in a trained network vs a completely untrained one on the same sign image.

Your output should look something like this (above)


In [22]:
### Visualize your network's feature maps here.
### Feel free to use as many code cells as needed.

# image_input: the test image being fed into the network to produce the feature maps
# tf_activation: should be a tf variable name used during your training procedure that represents the calculated state of a specific weight layer
# activation_min/max: can be used to view the activation contrast in more detail, by default matplot sets min and max to the actual min and max values of the output
# plt_num: used to plot out multiple different weight feature map sets on the same block, just extend the plt number for each new feature map entry

def outputFeatureMap(image_input, tf_activation, activation_min=-1, activation_max=-1 ,plt_num=1):
    # Here make sure to preprocess your image_input in a way your network expects
    # with size, normalization, ect if needed
    # image_input =
    # Note: x should be the same name as your network's tensorflow data placeholder variable
    # If you get an error tf_activation is not defined it may be having trouble accessing the variable from inside a function
    activation = tf_activation.eval(session=sess,feed_dict={x : image_input})
    featuremaps = activation.shape[3]
    plt.figure(plt_num, figsize=(15,15))
    for featuremap in range(featuremaps):
        plt.subplot(8,8, featuremap+1) # sets the number of feature maps to show on each row and column
        plt.title('FeatureMap ' + str(featuremap)) # displays the feature map number
        if activation_min != -1 & activation_max != -1:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", vmin =activation_min, vmax=activation_max, cmap="gray")
        elif activation_max != -1:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", vmax=activation_max, cmap="gray")
        elif activation_min !=-1:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", vmin=activation_min, cmap="gray")
        else:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", cmap="gray")

In [23]:
with tf.Session() as sess:
    saver.restore(sess, './traffic_classifier_data')
    print("Convolution #1")
    print(test_images[0].shape)
    print(test_images.shape)
    outputFeatureMap(test_images,conv1)


Convolution #1
(32, 32, 1)
(5, 32, 32, 1)

In [24]:
with tf.Session() as sess:
    saver.restore(sess, './traffic_classifier_data')
    print("Convolution #2")
    outputFeatureMap(test_images,conv2)


Convolution #2

In [25]:
with tf.Session() as sess:
    saver.restore(sess, './traffic_classifier_data')
    print("Convolution #3")
    outputFeatureMap(test_images,conv3)


Convolution #3

In [ ]: