A REMOTE SENSING IMAGE SEGMENTATION METHOD BASED ON SPECTRAL
AND STRUCTURE INFORMATION FUSION
Qinling Dai a Guoying Liu b Cancai Wang c Leiguang Wang* d
a School of Wood Science and Interior Design, Southwest Forestry University, 300 Bailongsi Road, Kunming, Yunnan,
China, 650224
b College of computer and commmunication engneering, Changsha University of Science & Techology, 76Chiling
Road,Changsha, China, 410079
c School of Polymer Science and Engineering, Qingdao University of Science & Technology, Zhengzhou
Road,Qingdao,Shandong,China,266042
d National Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University,
129 Luoyu Road, Wuhan, China, 430079
Commission VII, WG VII/6
KEY WORDS: Segmentation, Mean Shift, Information Fusion
ABSTRACT:
The focus of this paper is on the segmentation algorithm for the high resolution multispectral imagery to get regions which are
roughly corresponding to land cover types. We propose the combination of spectral features and spatial features by Gabor filter
banks and a variable mean shift clustering algorithm in high dimension is employed to achieve feature fusion. Some issues on the
measure metric of different features and standilzation are discussed. The whole algorithm is evaluated on the synthetic texture image,
which are cropped from a QuickBird image with typical land-cover types. Compared with fixed bandwidth Mean Shift segmentation
algorithm, our method has better performance in distinguishing the different land cover types with similar spectral surface.
1. INTRODUCTION
Image segmentation is a very important process in many image
vision applications, which involved in partitioning an image
into isolated regions, such that each region shares common
properties and represents a different object.(Jung,2007).A large
collection of literature on image segmentation has been
proposed over the past decades. Since image segmentation
represents the interface between image pre-processing and
image understanding, segmentation algorithms are often
application-dependent(Zhang et al.,2007).In our image
understanding target, segmentation regions are as a basis for the
following image classification mission. It is obvious that the
quality of classification is directly affected by segmentation
quality, so our segmentation algorithm focuses on partitioning
HR multi-spectral remote sensing images into isolated regions
which correspond to land-cover classes roughly. Compared
with close-range images, the HR or very high resolution (VHR)
remote sensing image is very rich in spatial detail and some
land cover classes have similar spectral representation, such as
glass and tree, road and roof. It means that the conventional
spectral features will be inadequate for the VHR imagery
segmentation. It seems evident that the VHR images do create
additional challenges in terms of information extraction and
classification (Dell'Acqua et al.,2004; LeiGuang et al.,2006;
Puissant et al.,2005; Xin et al.,2007).
Recently , a unified frame for gray and color image filter and
segmentation based on the mean shift (Comaniciu and
Meer,2002) presents good results for close-range images and
the most important is robust in feature space. In this algorithm,
a kernel in the spatial-range joint domain is defined, in which
spatial location with 2-dimension and the range feature with
image pixels in the CIE Luv color space is filtered, and then
filtered pixels are clustered together according to the threshold
of the minimum region defined by pixel count. Essentially,
image filtering (also called image smoothing) based on mean
shift is an instance of gradient ascent with an adaptive step size
in joint color-position domain and the segmentation is the
combination of seeking the mode of joint density in color-
position feature space and merging of modes. One attractive
property of image filtering based on mean shift is that the filter
result is discontinuity preserving, which means that pixels in a
region (mostly belonging to the same land-cover classes) will
be smoothed and the variability in the region is deduced, while
the boundary between regions has been preserved.
In our remote sensing image segmentation tasks, decomposition
of the multispectral image into homogenous tiles is desired, and
one tile can correspond to one kind of ground object roughly.
So our segmentation tasks are somewhat object-oriented.
Considering the spectral similarity of some pairs of ground
object, the general fixed-band mean shift based segmentation
in (Comaniciu and Meer,2002), which only clusters color or
gray level feature in image lattice, is not sufficient to getting
desirable segmentation result. The spectral similarity of
different land-cover types in HR imagery may lead to the
convergence of different classes to the same mode in the
spectral feature space. The discrimination performance of
spectral feature is further reduced. Considering the
* E-mail: corresponding author :wlgbain@gmail.com.