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Preface

Humans still obtain the vast majority of their sensory input through their vi-
sual system, and an enormous effort has been made to artificially enhance this
sense. Eyeglasses, binoculars, telescopes, radar, infrared sensors, and photo-
multipliers all function to improve our view of the world and the universe.
We even have telescopes in orbit (eyes outside the atmosphere) and many of
those ‘‘see’’ in other spectra: infrared, ultraviolet, X-rays. These give us views
that we could not have imagined only a few years ago, and in colors that we’ll
never see with the naked eye. The computer has been essential for creating the
incredible images we’ve all seen from these devices.
When the first edition of this book was written, the Hubble Space Telescope
was in orbit and producing images at a great rate. It and the European
Hipparcos telescope were the only optical instruments above the atmosphere.
Now there is COROT, Kepler, MOST (Canada’s space telescope), and Swift
Gamma Ray Burst Explorer. In addition, there is the Spitzer (infrared),
Chandra (X-ray), GALEX (ultraviolet), and a score of others. The first edition
was written on a 450-Mhz Pentium III with 256 MB of memory. In 1999, the
first major digital SLR camera was placed on the market: the Nikon D1. It
had only 2.74 million pixels and cost just under $6,000. A typical PC disk
drive held 100–200 MB. Webcams existed in 1997, but they were expensive
and low-resolution. Persons using computer images needed to have a special
image acquisition card and a relatively expensive camera to conduct their
work, generally amounting to $1–2,000 worth of equipment. The technology
of personal computers and image acquisition has changed a lot since then.
The 1997 first edition was inspired by my numerous scans though the
Internet news groups related to image processing and computer vision. I
noted that some requests appeared over and over again, sometimes answered
and sometimes not, and wondered if it would be possible to answer the more

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