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

12. Non-Maximum Suppression (NMS) algorithm

After the model training is completed, the network predicts bounding box offsets and corresponding categories. In some cases, two or more bounding boxes refer to the same object creating redundant predictions. The situation is shown in the case of a Soda can in Figure 11.12.1. To remove redundant predictions, a NMS algorithm is called. In this book, both classic NMS and soft NMS [6] are covered as shown in Algorithm 11.12.1. Both algorithms assume that bounding boxes and the corresponding confidence scores or probabilities are known.

Figure 11.12.1 The network predicted two overlapping bounding boxes for the Soda can object. Only one valid bounding box is chosen and that is the one with the higher score of 0.99.

In classic NMS, the final bounding boxes are selected based on probabilities and stored in list and with corresponding scores . All bounding boxes and corresponding probabilities are stored in initial lists and . In...