Book Image

PostGIS Cookbook - Second Edition

By : Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán
Book Image

PostGIS Cookbook - Second Edition

By: Pedro Wightman, Bborie Park, Stephen Vincent Mather, Thomas Kraft, Mayra Zurbarán

Overview of this book

PostGIS is a spatial database that integrates the advanced storage and analysis of vector and raster data, and is remarkably flexible and powerful. PostGIS provides support for geographic objects to the PostgreSQL object-relational database and is currently the most popular open source spatial databases. If you want to explore the complete range of PostGIS techniques and expose related extensions, then this book is for you. This book is a comprehensive guide to PostGIS tools and concepts which are required to manage, manipulate, and analyze spatial data in PostGIS. It covers key spatial data manipulation tasks, explaining not only how each task is performed, but also why. It provides practical guidance allowing you to safely take advantage of the advanced technology in PostGIS in order to simplify your spatial database administration tasks. Furthermore, you will learn to take advantage of basic and advanced vector, raster, and routing approaches along with the concepts of data maintenance, optimization, and performance, and will help you to integrate these into a large ecosystem of desktop and web tools. By the end, you will be armed with all the tools and instructions you need to both manage the spatial database system and make better decisions as your project's requirements evolve.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Introduction


In this chapter, the recipes are presented in a step-by-step workflow that you may apply while working with a raster. This entails loading the raster, getting a basic understanding of the raster, processing and analyzing it, and delivering it to consumers. We intentionally add some detours to the workflow to reflect the reality that the raster, in its original form, may be confusing and not suitable for analysis. At the end of this chapter, you should be able to take the lessons learned from the recipes and confidently apply them to solve your raster problems.

Before going further, we should describe what a raster is, and what a raster is used for. At the simplest level, a raster is a photo or image with information describing where to place the raster on the Earth's surface. A photograph typically has three sets of values: one set for each primary color (red, green, and blue). A raster also has sets of values, often more than those found in a photograph. Each set of values is...