Hyperspectral Image Classification Based on EMAPs Spatial-Spectral
Features Fusion and SMLR
Rong Ren
a,b
, Wenxing Bao*
a
a
School of Computer Science and Engineering, North Minzu University, YinChuan NingXia 750021;
b
School of computers and information, Hefei University of Technology,HeFei, AnHui 230009
ABSTRACT
This paper presents a novel classification method of hyperspectral image(HSI) based on EMAPs and SMLR. Firstly, we
adopt EMAPs(Extended Morphological multi-Attribute Profiles) algorithm to extract the spatial information of HSI
efficiently, and combine the spectral information to form spatial-spectral features fusion model. EMAPs can replace
simple structural elements with multiple attributes structure and cascade them to obtain attributes feature of multiple
structures. Then we utilize SMLR(Sparse Multinomial Logistic Regression) for HSI classification. SMLR is applicable
to high-dimensional and large data sets. A multiclass classifier based on MLR is adopted, and a fast algorithm is used to
learn a sparse multiclass classifier. Compared with other methods in HSI experiments, our method provides an excellent
result.
Keywords: hyperspectral image, classification, EMAPs, SMLR
1. INTRODUCTION
The advantage of hyperspectral image(HSI) is the combination of imagery and spectrum. The spectral information is
continuous, complete and informative. Hyperspectral remote sensing technology has been widely used in precision
agriculture, forestry monitoring, marine management, and environmental protection etc, and many valuable
achievements has been achieved
1
.
Classification is an important content and research focus of HSI analysis. Many classification techniques have been
developed for HSI, includes supervised classification method, such as SVM (Support Vector Machine), maximum
likelihood method, decision tree, minimum distance, artificial neural network classification, and unsupervised
classification method, such as K-Means and ISODATA. Machine learning technique (e.g., SVM or MLR(Multinomial
Logistic Regression)) has shown remarkable success
1,2
for HSI classification because of its superiorities in dealing with
high dimensional data and Hughes phenomenon
3,4
. Recently, sparse MLR(SMLR)
5
is investigated in many literatures,
and it was applied to HSI classification successfully
6,7
for its advantages of the fast and the applicability to large scale
data. Compare with the frequently-used method, such as SVM, SMLR has achieved better classification effect. However,
if SMLR method only make use of spectral feature, it will lead to outliers or inefficient classification.
In order to solve the problem, spatial-spectral combination classification
8,9,10
technology has become research hot spot
now. Spatial information can describe morphology, texture and edge features of HSI, so it is very significant to improve
HSI classification effect. EMAPs(Extended Morphological multi-Attribute Profiles) is an efficient algorithm to extract
spatial features of HSI.
The previous researches show that EMAPs is a powerful method to extract image features, and
feature extraction of spatial information can improve HSI class separability greatly
11,12
.
In this paper, we proposed a classification method innovatively based on EMAPs spatial-spectral fusion and SMLR. The
HSI classification experiments showed that the result of our proposed method is better than other methods.
The remainder of this paper is organized as follows. Section II describes the flow of our method and the relevant
algorithms such as EMAPs, SMLR. Section III presents experimental results using the HSI of Pavia University and
Indian Pines. Section IV concludes this paper and puts forward the future research work.
2. RESEARCH METHOD
2.1 The Flow of Proposed Method
Firstly, EMAPs algorithm is used to extract the spatial features of HSI. EMAPs can reconstruct the spatial and spectral
information of HSI from different directions. Then multi-features fusion model is built through combination of spatial
and spectral features. After random sampling, first-order neighborhood matrix is constructed. RBF ( Radial Basis Function)
13