xvi ■ Preface
● Expansion of the coverage on image segmentation to include more ad-
vanced edge detection techniques such as Canny’s algorithm, and a more
comprehensive treatment of image thresholding.
● An update of the chapter dealing with image representation and description.
● Streamlining the material dealing with structural object recognition.
The new and reorganized material that resulted in the present edition is our
attempt at providing a reasonable degree of balance between rigor, clarity of
presentation, and the findings of the market survey, while at the same time
keeping the length of the book at a manageable level. The major changes in
this edition of the book are as follows.
Chapter 1: A few figures were updated and part of the text was rewritten to
correspond to changes in later chapters.
Chapter 2: Approximately 50% of this chapter was revised to include new
images and clearer explanations. Major revisions include a new section on
image interpolation and a comprehensive new section summarizing the
principal mathematical tools used in the book. Instead of presenting “dry”
mathematical concepts one after the other, however, we took this opportu-
nity to bring into Chapter 2 a number of image processing applications that
were scattered throughout the book. For example, image averaging and
image subtraction were moved to this chapter to illustrate arithmetic opera-
tions.This follows a trend we began in the second edition of the book to move
as many applications as possible early in the discussion not only as illustra-
tions, but also as motivation for students. After finishing the newly organized
Chapter 2, a reader will have a basic understanding of how digital images are
manipulated and processed.This is a solid platform upon which the rest of the
book is built.
Chapter 3: Major revisions of this chapter include a detailed discussion of
spatial correlation and convolution, and their application to image filtering
using spatial masks. We also found a consistent theme in the market survey
asking for numerical examples to illustrate histogram equalization and specifi-
cation, so we added several such examples to illustrate the mechanics of these
processing tools. Coverage of fuzzy sets and their application to image pro-
cessing was also requested frequently in the survey. We included in this chap-
ter a new section on the foundation of fuzzy set theory, and its application to
intensity transformations and spatial filtering, two of the principal uses of this
theory in image processing.
Chapter 4: The topic we heard most about in comments and suggestions
during the past four years dealt with the changes we made in Chapter 4 from
the first to the second edition. Our objective in making those changes was to
simplify the presentation of the Fourier transform and the frequency domain.
Evidently, we went too far, and numerous users of the book complained that
the new material was too superficial.We corrected that problem in the present
edition.The material now begins with the Fourier transform of one continuous
variable and proceeds to derive the discrete Fourier transform starting with
basic concepts of sampling and convolution. A byproduct of the flow of this