Book Image

Learning QGIS - Third Edition

By : Anita Graser
Book Image

Learning QGIS - Third Edition

By: Anita Graser

Overview of this book

QGIS is a user-friendly open source geographic information system (GIS) that runs on Linux, Unix, Mac OS X, and Windows. The popularity of open source geographic information systems and QGIS in particular has been growing rapidly over the last few years. Learning QGIS Third Edition is a practical, hands-on guide updated for QGIS 2.14 that provides you with clear, step-by-step exercises to help you apply your GIS knowledge to QGIS. Through clear, practical exercises, this book will introduce you to working with QGIS quickly and painlessly. This book takes you from installing and configuring QGIS to handling spatial data to creating great maps. You will learn how to load and visualize existing spatial data and create data from scratch. You will get to know important plugins, perform common geoprocessing and spatial analysis tasks and automate them with Processing. We will cover how to achieve great cartographic output and print maps. Finally, you will learn how to extend QGIS using Python and even create your own plugin.
Table of Contents (13 chapters)
Learning QGIS Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Loading raster files


Loading raster files is not much different from loading vector files. Going to Layer | Add Layer | Add Raster Layer, clicking on the Add Raster Layer button, or pressing the Ctrl + Shift + R shortcut will take you directly to the file-opening dialog. Again, you can check the file type filter to see a list of supported file types.

Let's give it a try and load landcover.img from the raster sample data folder. Similarly to vector files, you can load rasters by dragging them into QGIS from the operating system or the built-in file browser. The following screenshot shows the loaded raster layer:

Note

Support for all of these different vector and raster file types in QGIS is handled by the powerful GDAL/OGR package. You can check out the full list of supported formats at www.gdal.org/formats_list.html (for rasters) and http://www.gdal.org/ogr_formats.html (for vectors).

Georeferencing raster maps

Some raster data sources, such as simple scanned maps, lack proper spatial referencing...