Book Image

Modern Computer Vision with PyTorch

By : V Kishore Ayyadevara, Yeshwanth Reddy
5 (2)
Book Image

Modern Computer Vision with PyTorch

5 (2)
By: V Kishore Ayyadevara, Yeshwanth Reddy

Overview of this book

Deep learning is the driving force behind many recent advances in various computer vision (CV) applications. This book takes a hands-on approach to help you to solve over 50 CV problems using PyTorch1.x on real-world datasets. You’ll start by building a neural network (NN) from scratch using NumPy and PyTorch and discover best practices for tweaking its hyperparameters. You’ll then perform image classification using convolutional neural networks and transfer learning and understand how they work. As you progress, you’ll implement multiple use cases of 2D and 3D multi-object detection, segmentation, human-pose-estimation by learning about the R-CNN family, SSD, YOLO, U-Net architectures, and the Detectron2 platform. The book will also guide you in performing facial expression swapping, generating new faces, and manipulating facial expressions as you explore autoencoders and modern generative adversarial networks. You’ll learn how to combine CV with NLP techniques, such as LSTM and transformer, and RL techniques, such as Deep Q-learning, to implement OCR, image captioning, object detection, and a self-driving car agent. Finally, you'll move your NN model to production on the AWS Cloud. By the end of this book, you’ll be able to leverage modern NN architectures to solve over 50 real-world CV problems confidently.
Table of Contents (25 chapters)
Section 1 - Fundamentals of Deep Learning for Computer Vision
Section 2 - Object Classification and Detection
Section 3 - Image Manipulation
Section 4 - Combining Computer Vision with Other Techniques

Working details of YOLO

You Only Look Once (YOLO) and its variants are one of the prominent object detection algorithms. In this section, we will understand at a high level how YOLO works and the potential limitations of R-CNN-based object detection frameworks that YOLO overcomes.

First, let's learn about the possible limitations of R-CNN-based detection algorithms. In Faster R-CNN, we slide over the image using anchor boxes and identify the regions that are likely to contain an object, and then we make the bounding box corrections. However, in the fully connected layer, where only the detected region's RoI pooling output is passed as input, in the case of regions that do not fully encompass the object (where the object is beyond the boundaries of the bounding box of region proposal), the network has to guess the real boundaries of object, as it has not seen the full image (but has seen only the region proposal).

YOLO comes in handy in such scenarios, as it looks at the whole...