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“4137X˙CH07˙Akerkar” — 2007/9/8 — 11:21 — page 284 — #22
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284 CHAPTER 7 Web Content Mining
queries that take advantage of spatial relations, such as “Find images with object 5 above
object 9.”
For retrieval-by-content with images, it is important to keep in mind that we can practically
work only with a restricted notion of semantic content, based on relatively simple “low-level”
measurements, such as color, texture, and simple geometric properties of objects. There are
numerous regular distortions in visual data: translations, rotations, scale variability, nonlinear
distortions, and so on. The human visual system is competent to manage certain ...