01 - Introduction

Abstract

There are many applications that involve digital images. They are created with modern digital cameras and scanners, rendered with advanced computer graphics techniques, or produced with drawing programs. Currently, there is a trend toward producing and using higher-resolution images. The vast majority of color images today are represented with a byte per pixel for each of the red, green, and blue channels. Images that store a depiction of the scene in a range of intensities commensurate with the scene are high-dynamic-range (HDR) images or “radiance maps.” On the other hand, the images suitable for display with current display technology are called low-dynamic-range (LDR) images. This book is specifically about HDR images. These images are not inherently different from LDR images, but there are many implications regarding the creation, storage, use, and display of such images. The technology required to create, store, manipulate, and display HDR images is only just emerging; there is already a substantial body of research available on HDR imaging, which is collected and catalogued in this book. The major areas addressed in this book are light and color HDR, HDR image capture, HDR image representation, HDR display devices, image-based lighting, dynamic range reduction, and tone reproduction. Although the concept of HDR imaging is straightforward (i.e., representing scenes with values commensurate with real-world light levels), the implications to all aspects of imaging are profound. In this book, opportunities and challenges with respect to HDR image acquisition, storage, processing, and display are cataloged.