Assessment of Ensemble Classifiers Using the Bagging
Technique for Improved Land Cover Classification of
multispectral Satellite Images
Hassan Mohamed1,
Abdelazim Negm1, Mohamed Zahran2, and Oliver Saavedra3
1Department of Environmental
Engineering, Egypt-Japan University of Science and Technology, Egypt
2Department of Geomatics
Engineering, Benha University, Egypt
3Department of Civil Engineering,
Tokyo Institute of Technology, Japan
Abstract: This study evaluates an approach for Land-Use Land-Cover classification (LULC) using
multispectral satellite images. This proposed approach uses the Bagging Ensemble (BE) technique with Random Forest (RF) as a base
classifier for improving classification performance by reducing errors and
prediction variance. A pixel-based supervised classification technique
with Principle Component Analysis (PCA) for feature selection from available
attributes using a Landsat 8 image is developed. These attributes include
coastal, visible, near-infrared, short-wave infrared and thermal bands in addition to Normalized Difference Vegetation Index (NDVI) and
Normalized Difference Water Index (NDWI). The study is performed in a
heterogeneous coastal area divided into five classes: water, vegetation,
grass-lake-type, sand, and building. To evaluate the
classification accuracy of BE with RF, it is compared to BE with Support Vector
Machine (SVM) and Neural Network (NN) as base classifiers. The results are evaluated using the following output: commission, omission errors, and overall accuracy. The results showed
that the proposed approach using BE with RF outperforms SVM and NN classifiers
with 93.3% overall accuracy. The BE with SVM and NN classifiers yielded 92.6%
and 92.1% overall accuracy, respectively. It is revealed that using BE
with RF as a base classifier outperforms other base classifiers as SVM and NN.
In addition, omission and commission errors were reduced by using BE with RF and NN classifiers.
Keywords: Bagging; classification; ensemble; landsat satellite magery.
Received May 25, 2015; accepted January 13, 2016