Journal of Geo-information Science >
Change Detection and Analysis of Landsat-8 Image Based on LDA Model
Received date: 2014-08-25
Request revised date: 2014-11-28
Online published: 2015-03-10
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Change detection with remote sensing images plays an important role in land cover mapping. With the development of science and technology, a series of new remote sensing data sources have become available, and have been significantly improved, which also brings a great challenge to the traditional remote sensing change detection methods. Unlike the other traditional methods for change detection, the present work uses Latent Dirichlet Allocation model (LDA) in learning middle-level semantic topics instead of low-level features from remote sensing images. In this paper, we use the pixels of two remote sensing images as the basic unit, while the image segments are used as the documents in the object-based image analysis methods. Firstly, we try to extract some features from these remote sensing images, such as the spectral and textural features. Then, we work on organizing the local features from these two images to obtain visual words and construct the bag of words model (BOWM) representation. Based on this, the LDA model is utilized to reveal the underlying topics, which are used to detect the change of the study area. Every document of remote sensing images has a specific topic distribution, which is related to the reference data of the study area. In this process, the pseudo changes and actual changes of these two remote sensing images can be distinguished by the topic distributions of the documents. Compared with traditional pixel-level change detection methods,the method of LDA-based model is less influenced by the spectral variance of two images, which avoids the “salt and pepper” effect by using object-based analysis method. The effectiveness of LDA-based model change detection approach was verified in experiments with the accuracy to be 85.35%, and it is also compared with techniques using Spectral Angle Mapper and Image differencing. The result shows that our studies provide a good approach to improve the accuracy and reduce the mistake rate of change detection between two images. Our work indicates that LDA model-based approach is superior to the traditional methods and the proposed method is applicable to the analysis of change area detection using Landsat-8 images.
Key words: Landsat-8; change detection; object-oriented; LDA model; the bag of words model
LI Yang , JIANG Nan , SHI Hao , SHAO Hua . Change Detection and Analysis of Landsat-8 Image Based on LDA Model[J]. Journal of Geo-information Science, 2015 , 17(3) : 353 -360 . DOI: 10.3724/SP.J.1047.2015.00353
Fig. 1 False color composite Landsat-8 images of the study area图1 研究区Landsat-8遥感影像(假彩色合成) |
Fig. 2 The general process of LDA model图2 LDA模型结构示意图 |
Fig. 3 Flowchart of change detection based on LDA model图3 基于LDA模型的变化检测技术流程图 |
Fig. 4 Result of multiresolution segmentation of the study area图4 研究区2期影像分割结果 |
Fig. 5 Topic distrbution of the actural ground features图5 实际地物的主题分布 |
Fig. 6 Comparison of the change detection results of three methods图6 不同方法的变化检测结果比较 |
Tab. 1 Accuracy of change detections with different number of visual words and topics表1 不同视觉单词数和主题数情况下的模型变化检测正确率 |
觉单词数量 | 各主题数下的正确率(%) | |||
---|---|---|---|---|
4 | 8 | 12 | 16 | |
50 | 80.23 | 83.46 | 81.76 | 80.10 |
100 | 81.37 | 85.35 | 83.22 | 81.21 |
150 | 80.75 | 84.21 | 84.36 | 79.87 |
200 | 79.56 | 83.56 | 83.43 | 79.87 |
Fig. 7 Comparative results between LDA models with significant change document and no-change document图7 显著变化和未变化文档(图斑)LDA模型分析结果对比 |
Tab. 2 Accuracy of different change detection approaches表2 不同模型变化检测精度评价表 |
模型 | 漏检率(%) | 误检率(%) | 正确率(%) |
---|---|---|---|
LDA模型的变化检测方法 | 8.45 | 6.20 | 85.35 |
差值变化检测方法 | 13.35 | 14.15 | 72.50 |
波谱角变化检测方法 | 8.29 | 7.50 | 84.21 |
The authors have declared that no competing interests exist.
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