IMAGE SEGMENTATION FROM TEXTURE MEASUREMENT
Dong-Cheon Lee
Toni Schenk
Department of Geodetic Science and Surveying
The Ohio State University
Columbus, OH 43210-1247
U.S. A.
Commission III
ABSTRACT
It is known that the human visual system, unsurpassed in its ability to reconstruct surfaces, employs different cues
to solve this difficult task. The prevailing method in digital photogrammetry is stereopsis. However, texture may
provide valuable information about the shape of surfaces. In this paper we employ Laws' method of texture
energy transforms to extract texture information from digital aerial imagery. The images are convolved with
micro-texture filters to obtain local texture properties. Each micro-texture feature plane is transformed into an
texture energy image by moving-window to render macro-texture features. Finally, the macro-texture feature
planes are combined and then clustered into regions of similar texture pattern. The method is implemented in a
scale-space approach, and the boundaries obtained from texture are compared with physical boundaries of the
image.
KEY WORDS: Texture primitive, Micro-texture, Macro-texture, Texture energy, Image Analysis.
1. INTRODUCTION
The goal of digital photogrammetry is to reconstruct
surfaces automatically. Surface reconstruction from
raw imagery is known as an ill-posed problem. To
solve this difficult task, different cues which
contribute to object recognition and scene
interpretation are employed. One of the important
cues is texture. Texture may provide information to
estimate shape, surface orientation, depth changes,
material of objects. Texture information aids image
analysis and interpretation.
Many texture analysis methods have been developed
during the last two decades. Among the great variety
of available methods, Laws' approach of texture
energy measures appears to be a suitable method
(Ballard and Brown, 1982; Gool et af, 1985; Gong
and Huang, 1988; Unser and Eden, 1990).
Furthermore, this method resembles human visual
processing of texture according to Laws' dissertation.
One of the advantages of this method is to provide
several texture feature planes from an original image.
This is a great benefit especially if only monochrome
imagery is available because to extract useful texture
information from raw monochrome images is a
difficult task even for the human vision system. More
useful information and segmentation results could be
obtained by integrating the additional texture feature
planes.
2. CHARACTERISTICS OF TEXTURE
Texture is qualitatively described by its coarseness
under the same viewing condition, and related to the
repetition of the local spatial patterns. In addition to
coarseness, other textural dimensions or parameters
are commonly proposed, namely, contrast, density,
roughness, directionality, frequency, regularity,
uniformity, orientation, and so on (Tamura et af,
1978).
Texture is a sophisticate visual primitive since texture
element (texel) is determined by contextual process
and a different level of hierarchy. Texture primitives
consists of micro-texture and macro-texture. Micro-
texture is the smallest primitive while macro-texture is
referred to larger primitive, i.e., macro-texture is
homogeneous aggregation of micro-texture. These
two primitives cannot be confused with fine texture
and coarse texture. The coarseness of texture is
related to the spatial repetition period of the local
structure. Therefore, micro-texture and macro-texture
are not related the coarseness. However, in fact there
are not clear criteria to differentiate micro-texture
from macro-texture primitives, rather it is related to
somewhat psychological effect as well as image scale
and resolution. Since texture is hierarchical, texture
within texture primitives themselves is visible (Gool
et al, 1985). It is important to understand how the
human visual system works for texture discrimination
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