In this webinar, SigOpt ML Engineer Meghana Ravikumar presents on and builds an image classifier trained on the Stanford Cars dataset to evaluate two approaches to transfer learning—fine tuning and feature extraction—and the impact of Multitask optimization, a more efficient form of Bayesian optimization, on these techniques. Once we define the most performant transfer learning technique for Stanford Cars, we will use image augmentation to double the size of the dataset to boost the classifier’s performance. Instead of manually tuning the hyperparameters associated with image augmentation, we will use Multitask Optimization to learn these hyperparameters using the downstream image classifier’s performance as the guide. In conjunction with model performance, we will also explore the features of these augmented images and the downstream implications for our image classifier.

8. ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
Input
Convolutional Features
Classification
Input
Convolutional Features
Classification

11. ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
Car Image Data
Convolutional
Features
Classification

13. Partial Full

16. Acura
TLX
2015
https://arxiv.org/abs/1512.03385

18. Low Cost
10% of epochs
Medium Cost
50% of epochs
Full Cost
100% of epochs

20. ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
Input
Convolutional Features
Classification
Input
Convolutional Features
Classification

22. ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
Car Image Data
Convolutional
Features
Classification

28. Stanford
Cars
Dataset
Image
Augmentation
Model Training
(ResNet 18
fine-tuned)
Model
Accuracy
SigOpt
Model Validation Accuracy
Suggested
Hyperparameters Suggested
Hyperparameters

31. ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
Input
Convolutional Features
Classification

32. ImageNet Pretrained
Convolutional Layers
Fully Connected Layer
Input
Convolutional Features
Classification
Cars Image Data
Image Augmentation
Accuracy