dhkim0225 / carnd-traffic_sign_classifier

Udacity Self Driving Car Nanodegree Project 2

Traffic Sign Classifier

Udacity Self Driving Car Nanodegree project 2.

This project classify traffic sign with simple Convolutinon Network.

Dataset

German_Traffic_Sign_Dataset

I used the numpy and basic python operations to calculate summary statistics of the traffic signs data set.

• The size of training set is 34799.
• The size of test set is 12630.
• The shape of a traffic sign image is (32, 32, 3).
• The number of unique classes/labels in the data set is 43.

Preprocessing

Preprocessing pipeline has 3 steps.

1. GrayScaling.
2. Normalization with MinMaxScaler(scikit-learn).
3. Shuffle data.

Model Architecture

Layer	Description
Input	32x32x3 RGB image
Convolution 5x5	1x1 stride, same padding, outputs 32x32x8
RELU
Max pooling	2x2 stride, outputs 16x16x8
Convolution 5x5	1x1 stride, same padding, outputs 16x16x16
RELU
Max pooling	2x2 stride, outputs 8x8x16
Fully connected	W.shap (8816, 300), dropout_rate(learn) 0.7
Fully connected	W.shap (300, 120), dropout_rate(learn) 0.7
Fully connected	W.shap (120, 43), dropout_rate(learn) 0.7
Softmax

Result

• cost = 0.013
• validation set accuracy = 0.949
• test set accuracy = 0.942

Test

Here are five German traffic signs that I found on the web:

Here are the results of the prediction:

Image	Prediction
No entry	No entry
Stop	Stop
Speed limit (60km/h)	Speed limit (60km/h)
Go straight or left	Go straight or left
Go straight or right	Go straight or right

The model was able to correctly guess 5 of the 5 traffic signs, which gives an accuracy of 100%.

top-5 test output

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Probability	Prediction
1	No entry
1.1e-25	Stop
2.5e-28	Yield
5.9e-31	End of all speed and passing limits
2.8e-33	Speed limit (120km/h)

---

Probability	Prediction
0.84	Stop
0.13	Yield
7.6e-3	No vehicles
4.4e-5	Speed limit (50km/h)
2.1e-6	Speed limit (60km/h)

---

Probability	Prediction
0.99	Speed limit (60km/h)
1.0e-5	Speed limit (80km/h)
2.2e-7	End of speed limit (80km/h)
2.0e-8	Speed limit (50km/h)
2.4e-9	Speed limit (30km/h)

---

Probability	Prediction
0.98	Go straight or left
1.4e-2	No entry
1.3e-5	Keep left
6.8e-8	Roundabout mandatory
6.8e-12	Ahead only

---

Probability	Prediction
0.80	Go straight or right
0.15	No entry
0.05	Keep right
8.5e-4	End of all speed and passing limits
7.6e-4	End of no passing

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