"Working with digital images requires some understanding of what needs to be done. It's not a ``choose the right tool, one click, and you're done'' subject. Most books on digital image manipulation would have you believe the contrary...and perhaps they're right. However, that is not what this book is about. It is not about tips and tricks, and it's not a collection of recipes for solving someone's favorite image manipulation problems. It is first about understanding image manipulation concepts, second about knowing which GIMP tools are most effective, and third about the savvy use of these tools.
Many factors have contributed to the style and content of the material presented in this book. My educational training in signal processing, my professional work in various areas of imaging and image processing, the research I've done on colorspaces and image manipulation, and lots of experimentation with the GIMP. The result is a book that covers many areas of working with digital images, including touchup and enhancement, compositing, 3D rendering, and the presentation of graphics on the World Wide Web. This book also gives a unified and in-depth introduction to layers, selections, masks, colorspaces, and the use of blending modes."