Book Image

Advanced Deep Learning with TensorFlow 2 and Keras - Second Edition

By : Rowel Atienza
Book Image

Advanced Deep Learning with TensorFlow 2 and Keras - Second Edition

By: Rowel Atienza

Overview of this book

Advanced Deep Learning with TensorFlow 2 and Keras, Second Edition is a completely updated edition of the bestselling guide to the advanced deep learning techniques available today. Revised for TensorFlow 2.x, this edition introduces you to the practical side of deep learning with new chapters on unsupervised learning using mutual information, object detection (SSD), and semantic segmentation (FCN and PSPNet), further allowing you to create your own cutting-edge AI projects. Using Keras as an open-source deep learning library, the book features hands-on projects that show you how to create more effective AI with the most up-to-date techniques. Starting with an overview of multi-layer perceptrons (MLPs), convolutional neural networks (CNNs), and recurrent neural networks (RNNs), the book then introduces more cutting-edge techniques as you explore deep neural network architectures, including ResNet and DenseNet, and how to create autoencoders. You will then learn about GANs, and how they can unlock new levels of AI performance. Next, you’ll discover how a variational autoencoder (VAE) is implemented, and how GANs and VAEs have the generative power to synthesize data that can be extremely convincing to humans. You'll also learn to implement DRL such as Deep Q-Learning and Policy Gradient Methods, which are critical to many modern results in AI.
Table of Contents (16 chapters)
14
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15
Index

5. SSD model architecture

Figure 11.5.1 shows the model architecture of SSD that implements the conceptual framework of multi-scale single-shot object detection. The network accepts an RGB image and outputs several levels of prediction. A base or backbone network extracts features for the downstream task of classification and offset predictions. A good example of a backbone network is ResNet50 that is similar to what was discussed, implemented, and evaluated in Chapter 2, Deep Neural Networks. After the backbone network, the object detection task is performed by the rest of the network which we call SSD head.

The backbone network can be a pre-trained network with frozen weights (for example; previously trained for ImageNet classification) or jointly trained with object detection. If we used a pre-trained base network, we take advantage of reusing previously learned feature extraction filters from a large dataset. In addition, it accelerates learning as the backbone network...