Image Enhancement and
Analysis with Weighted
Medians
GONZALO R. ARCE AND JOSE L. PAREDES*
Department of Electrical and Computer Engineering
University of Delaware
Newark, Delaware
2.1 Introduction
Digital image enhancement and analysis have played and will continue to play an
important role in scientific, industrial, and military applications. In addition to
these, image enhancement and analysis are being used increasingly in consumer
electronics. World Wide Web users, for instance, not only rely on built-in image
processing protocols such as JPEG and interpolation but also have become image
processing users equipped with powerful yet inexpensive software such as Pho-
toShop. Users not only retrieve digital images from the Web but now are able to
acquire their own by use of digital cameras or through digitization services of
standard 35-mm analog film. The end result is that consumers are beginning to
use home computers to enhance and manipulate their own digital pictures.
Image enhancement tools are often classified into (a) point operations and (b)
spatial operators. Point operations include contrast stretching, histogram modi-
fication, and pseudo-coloring. Point operations are, in general, simple nonlinear
*Jos~ L. Paredes is also with the Electrical Engineering Department, University of Los Andes,
M~rida-Venezuela.
27

Get Nonlinear Image Processing now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.