scholarly journals ASSESSMENT OF MULTIRESOLUTION SEGMENTATION FOR EXTRACTING GREENHOUSES FROM WORLDVIEW-2 IMAGERY

2016 ◽  
Vol XLI-B7 ◽  
pp. 145-152 ◽  
Author(s):  
M. A. Aguilar ◽  
F. J. Aguilar ◽  
A. García Lorca ◽  
E. Guirado ◽  
M. Betlej ◽  
...  
Keyword(s):  
Image Objects ◽  
Object Based Image Analysis ◽  
Local Variance ◽  
Sensing Applications ◽  
Object Based ◽  
Optimum Scale ◽  
Values Assessment ◽  
Segmentation Approach ◽  
Optimal Setting ◽  
Multiresolution Segmentation

The latest breed of very high resolution (VHR) commercial satellites opens new possibilities for cartographic and remote sensing applications. In this way, object based image analysis (OBIA) approach has been proved as the best option when working with VHR satellite imagery. OBIA considers spectral, geometric, textural and topological attributes associated with meaningful image objects. Thus, the first step of OBIA, referred to as segmentation, is to delineate objects of interest. Determination of an optimal segmentation is crucial for a good performance of the second stage in OBIA, the classification process. The main goal of this work is to assess the multiresolution segmentation algorithm provided by eCognition software for delineating greenhouses from WorldView- 2 multispectral orthoimages. Specifically, the focus is on finding the optimal parameters of the multiresolution segmentation approach (i.e., Scale, Shape and Compactness) for plastic greenhouses. The optimum Scale parameter estimation was based on the idea of local variance of object heterogeneity within a scene (ESP2 tool). Moreover, different segmentation results were attained by using different combinations of Shape and Compactness values. Assessment of segmentation quality based on the discrepancy between reference polygons and corresponding image segments was carried out to identify the optimal setting of multiresolution segmentation parameters. Three discrepancy indices were used: Potential Segmentation Error (PSE), Number-of-Segments Ratio (NSR) and Euclidean Distance 2 (ED2).

scholarly journals ASSESSMENT OF MULTIRESOLUTION SEGMENTATION FOR EXTRACTING GREENHOUSES FROM WORLDVIEW-2 IMAGERY

2016 ◽  
Vol XLI-B7 ◽  
pp. 145-152 ◽  
Author(s):  
M. A. Aguilar ◽  
F. J. Aguilar ◽  
A. García Lorca ◽  
E. Guirado ◽  
M. Betlej ◽  
...  
Keyword(s):  
Image Objects ◽  
Object Based Image Analysis ◽  
Local Variance ◽  
Sensing Applications ◽  
Object Based ◽  
Optimum Scale ◽  
Values Assessment ◽  
Segmentation Approach ◽  
Optimal Setting ◽  
Multiresolution Segmentation

The latest breed of very high resolution (VHR) commercial satellites opens new possibilities for cartographic and remote sensing applications. In this way, object based image analysis (OBIA) approach has been proved as the best option when working with VHR satellite imagery. OBIA considers spectral, geometric, textural and topological attributes associated with meaningful image objects. Thus, the first step of OBIA, referred to as segmentation, is to delineate objects of interest. Determination of an optimal segmentation is crucial for a good performance of the second stage in OBIA, the classification process. The main goal of this work is to assess the multiresolution segmentation algorithm provided by eCognition software for delineating greenhouses from WorldView- 2 multispectral orthoimages. Specifically, the focus is on finding the optimal parameters of the multiresolution segmentation approach (i.e., Scale, Shape and Compactness) for plastic greenhouses. The optimum Scale parameter estimation was based on the idea of local variance of object heterogeneity within a scene (ESP2 tool). Moreover, different segmentation results were attained by using different combinations of Shape and Compactness values. Assessment of segmentation quality based on the discrepancy between reference polygons and corresponding image segments was carried out to identify the optimal setting of multiresolution segmentation parameters. Three discrepancy indices were used: Potential Segmentation Error (PSE), Number-of-Segments Ratio (NSR) and Euclidean Distance 2 (ED2).

scholarly journals LANDSLIDE EXTRACTION FROM SENTINEL-2 IMAGE IN SIWALIK OF SURKHET DISTRICT, NEPAL

2019 ◽  
Vol IV-5/W2 ◽  
pp. 9-15
Author(s):  
P. B. Budha ◽  
A. Bhardwaj
Keyword(s):  
Satellite Images ◽  
Threshold Value ◽  
Threshold Values ◽  
Geometrical Properties ◽  
Image Objects ◽  
Object Based Image Analysis ◽  
Loss And Damage ◽  
Object Based ◽  
Multiresolution Segmentation ◽  
Sentinel 2

Abstract. Locating landslides and determining its extent is deemed an important task in estimating loss and damage and carry out mitigation works. As landslides are recurring phenomena in the research site, Siwalik Hills of western Nepal, freely available Sentinel-2 satellite images were considered to delineate landslides. The method employed in this process was Object-Based Image Analysis carried out in eCognition software using multiresolution segmentation algorithm. Parameters taken for segmentation were a scale of 20, the shape of 0.3, and compactness of 0.5. When a threshold value of < 0.35 in NDVI was used to distinguish landslides from image objects, some non-landslide objects were also selected. These false positives were removed successively using the threshold values on different bands, band ratios, slope information, hillshade and geometrical properties of image objects. There were altogether 264 landslides detected in the study area with size ranging from 300 m2 to 1675 m2 and landslide density of approximately 2 per km2. The accuracy, when compared to reference inventory, showed correctness and completeness measuring 80.28% and 66.27% respectively. These results showed semi-automatic landslide extraction was successful and Sentinel-2 can be used for similar tasks in other areas of Siwalik.

scholarly journals Parameter-Based Performance Analysis of Object-Based Image Analysis Using Aerial and Quikbird-2 Images

2014 ◽  
Vol II-7 ◽  
pp. 31-37 ◽  
Author(s):  
T. Kavzoglu ◽  
M. Yildiz
Keyword(s):  
Image Analysis ◽  
Accuracy Assessment ◽  
Data Sets ◽  
Image Objects ◽  
Object Based Image Analysis ◽  
Local Variance ◽  
Object Based ◽  
Segmented Images ◽  
Nearest Neighbour Classifier ◽  
Segmentation Parameters

Opening new possibilities for research, very high resolution (VHR) imagery acquired by recent commercial satellites and aerial systems requires advanced approaches and techniques that can handle large volume of data with high local variance. Delineation of land use/cover information from VHR images is a hot research topic in remote sensing. In recent years, object-based image analysis (OBIA) has become a popular solution for image analysis tasks as it considers shape, texture and content information associated with the image objects. The most important stage of OBIA is the image segmentation process applied prior to classification. Determination of optimal segmentation parameters is of crucial importance for the performance of the selected classifier. In this study, effectiveness and applicability of the segmentation method in relation to its parameters was analysed using two VHR images, an aerial photo and a Quickbird-2 image. Multi-resolution segmentation technique was employed with its optimal parameters of scale, shape and compactness that were defined after an extensive trail process on the data sets. Nearest neighbour classifier was applied on the segmented images, and then the accuracy assessment was applied. Results show that segmentation parameters have a direct effect on the classification accuracy, and low values of scale-shape combinations produce the highest classification accuracies. Also, compactness parameter was found to be having minimal effect on the construction of image objects, hence it can be set to a constant value in image classification.

scholarly journals Unsupervised Segmentation Evaluation Using Area-Weighted Variance and Jeffries-Matusita Distance for Remote Sensing Images

2018 ◽  
Vol 10 (8) ◽  
pp. 1193 ◽  
Author(s):  
Yongji Wang ◽  
Qingwen Qi ◽  
Ying Liu
Keyword(s):  
Distance Measures ◽  
Unsupervised Segmentation ◽  
Segmentation Evaluation ◽  
Object Based Image Analysis ◽  
Object Based ◽  
Segmentation Methods ◽  
Segmentation Quality ◽  
Two Measures ◽  
Multiresolution Segmentation ◽  
Adjacent Segments

Image segmentation is an important process and a prerequisite for object-based image analysis. Thus, evaluating the performance of segmentation algorithms is essential to identify effective segmentation methods and to optimize the scale. In this paper, we propose an unsupervised evaluation (UE) method using the area-weighted variance (WV) and Jeffries-Matusita (JM) distance to compare two image partitions to evaluate segmentation quality. The two measures were calculated based on the local measure criteria, and the JM distance was improved by considering the contribution of the common border between adjacent segments and the area of each segment in the JM distance formula, which makes the heterogeneity measure more effective and objective. Then the two measures were presented as a curve when changing the scale from 8 to 20, which can reflect the segmentation quality in both over- and under-segmentation. Furthermore, the WV and JM distance measures were combined by using three different strategies. The effectiveness of the combined indicators was illustrated through supervised evaluation (SE) methods to clearly reveal the segmentation quality and capture the trade-off between the two measures. In these experiments, the multiresolution segmentation (MRS) method was adopted for evaluation. The proposed UE method was compared with two existing UE methods to further confirm their capabilities. The visual and quantitative SE results demonstrated that the proposed UE method can improve the segmentation quality.

scholarly journals Geographic Object-Based Image Analysis: A Primer and Future Directions

2020 ◽  
Vol 12 (12) ◽  
pp. 2012 ◽  
Author(s):  
Maja Kucharczyk ◽  
Geoffrey J. Hay ◽  
Salar Ghaffarian ◽  
Chris H. Hugenholtz
Keyword(s):  
Image Analysis ◽  
Current Status ◽  
Future Research ◽  
Deep Convolutional Neural Networks ◽  
Comprehensive Overview ◽  
Image Objects ◽  
Object Based Image Analysis ◽  
Object Based ◽  
Geographic Object ◽  
Methodological Considerations

Geographic object-based image analysis (GEOBIA) is a remote sensing image analysis paradigm that defines and examines image-objects: groups of neighboring pixels that represent real-world geographic objects. Recent reviews have examined methodological considerations and highlighted how GEOBIA improves upon the 30+ year pixel-based approach, particularly for H-resolution imagery. However, the literature also exposes an opportunity to improve guidance on the application of GEOBIA for novice practitioners. In this paper, we describe the theoretical foundations of GEOBIA and provide a comprehensive overview of the methodological workflow, including: (i) software-specific approaches (open-source and commercial); (ii) best practices informed by research; and (iii) the current status of methodological research. Building on this foundation, we then review recent research on the convergence of GEOBIA with deep convolutional neural networks, which we suggest is a new form of GEOBIA. Specifically, we discuss general integrative approaches and offer recommendations for future research. Overall, this paper describes the past, present, and anticipated future of GEOBIA in a novice-accessible format, while providing innovation and depth to experienced practitioners.

scholarly journals A Framework for Geographic Object-Based Image Analysis (GEOBIA) based on geographic ontology

2015 ◽  
Vol XL-7/W4 ◽  
pp. 27-33 ◽  
Author(s):  
H. Y. Gu ◽  
H. T. Li ◽  
L. Yan ◽  
X. J. Lu
Keyword(s):  
Remote Sensing ◽  
Image Analysis ◽  
Systematic Approach ◽  
Semantic Network ◽  
Image Objects ◽  
Object Based Image Analysis ◽  
Object Based ◽  
Geographic Object ◽  
Objective Model

GEOBIA (Geographic Object-Based Image Analysis) is not only a hot topic of current remote sensing and geographical research. It is believed to be a paradigm in remote sensing and GIScience. The lack of a systematic approach designed to conceptualize and formalize the class definitions makes GEOBIA a highly subjective and difficult method to reproduce. This paper aims to put forward a framework for GEOBIA based on geographic ontology theory, which could implement "Geographic entities - Image objects - Geographic objects" true reappearance. It consists of three steps, first, geographical entities are described by geographic ontology, second, semantic network model is built based on OWL(ontology web language), at last, geographical objects are classified with decision rule or other classifiers. A case study of farmland ontology was conducted for describing the framework. The strength of this framework is that it provides interpretation strategies and global framework for GEOBIA with the property of objective, overall, universal, universality, etc., which avoids inconsistencies caused by different experts’ experience and provides an objective model for mage analysis.

scholarly journals PEMETAAN ZONA GEOMORFOLOGI DAN HABITAT BENTIK DI PULAU KOTOK BESAR MENGGUNAKAN KLASIFIKASI BERBASIS OBJEK

2018 ◽  
Vol 8 (2) ◽  
pp. 209-219
Author(s):  
Ike Dori Candra ◽  
Vicentius P. Siregar ◽  
Syamsul B. Agus
Keyword(s):  
Image Analysis ◽  
Reef Flat ◽  
Reef Slope ◽  
Reef Crest ◽  
Object Based Image Analysis ◽  
Object Based ◽  
Level 3 ◽  
Level 1 ◽  
Multiresolution Segmentation ◽  
Level 2

Penelitian ini menggunakan citra satelit resolusi tinggi worldview-2 akuisisi 5 Oktober 2013. Tujuan dari penelitian ini adalah untuk mengkaji kemampuan citra satelit resolusi tinggi worldview-2 dalam memetakan zona geomorfologi dan habitat bentik perairan dangkal di Pulau Kotok Besar. Metode yang digunakan adalah metode klasifikasi Object Based Image Analysis (OBIA). Metode ini mampu mendefinisikan kelas-kelas objek berdasarkan aspek spektral dan spasial. Segmentasi citra menggunakan algoritma multiresolution segmentation dengan parameter skala yang berbeda untuk setiap level, baik level 1, level 2 dan level 3. Shape dan compactness juga disesuaikan untuk setiap level. Penentuan kelas pada level 1 menghasilkan tiga kelas yaitu daratan, perairan dangkal dan perairan dalam. Penentuan kelas pada level 2 untuk zona geomorfologi menghasilkan tiga kelas yaitu reef flat, reef crest dan reef slope. Klasifikasi habitat bentik pada level 3 menghasilkan 7 kelas dengan akurasi keseluruhan yaitu 66.40 %.

scholarly journals APPLICABILITY OF MULTI-SEASONAL X-BAND SAR IMAGERY FOR MULTIRESOLUTION SEGMENTATION: A CASE STUDY IN A RIPARIAN MIXED FOREST

2015 ◽  
Vol XL-1-W5 ◽  
pp. 123-128
Author(s):  
Z. Dabiri ◽  
D. Hölbling ◽  
S. Lang ◽  
A. Bartsch
Keyword(s):  
Scale Parameter ◽  
Spatial Scales ◽  
Mixed Forest ◽  
Scale Parameters ◽  
Image Objects ◽  
Object Based ◽  
Multi Temporal ◽  
Reference Map ◽  
Sar Imagery ◽  
Multiresolution Segmentation

The increasing availability of synthetic aperture radar (SAR) data from a range of different sensors necessitates efficient methods for semi-automated information extraction at multiple spatial scales for different fields of application. The focus of the presented study is two-fold: 1) to evaluate the applicability of multi-temporal TerraSAR-X imagery for multiresolution segmentation, and 2) to identify suitable Scale Parameters through different weighing of different homogeneity criteria, mainly colour variance. Multiresolution segmentation was used for segmentation of multi-temporal TerraSAR-X imagery, and the ESP (Estimation of Scale Parameter) tool was used to identify suitable Scale Parameters for image segmentation. The validation of the segmentation results was performed using very high resolution WorldView-2 imagery and a reference map, which was created by an ecological expert. The results of multiresolution segmentation revealed that in the context of object-based image analysis the TerraSAR-X images are applicable for generating optimal image objects. Furthermore, ESP tool can be used as an indicator for estimation of Scale Parameter for multiresolution segmentation of TerraSAR-X imagery. Additionally, for more reliable results, this study suggests that the homogeneity criterion of colour, in a variance based segmentation algorithm, needs to be set to high values. Setting the shape/colour criteria to 0.005/0.995 or 0.00/1 led to the best results and to the creation of adequate image objects.

scholarly journals A NEW FRAMEWORK FOR OBJECT-BASED IMAGE ANALYSIS BASED ON SEGMENTATION SCALE SPACE AND RANDOM FOREST CLASSIFIER

2015 ◽  
Vol XL-1-W5 ◽  
pp. 263-268 ◽  
Author(s):  
A. Hadavand ◽  
M. Saadatseresht ◽  
S. Homayouni
Keyword(s):  
Image Analysis ◽  
Land Cover ◽  
Scale Space ◽  
Aerial Image ◽  
Surface Model ◽  
Image Objects ◽  
Object Based Image Analysis ◽  
Object Based ◽  
Land Cover Map ◽  
New Framework

In this paper a new object-based framework is developed for automate scale selection in image segmentation. The quality of image objects have an important impact on further analyses. Due to the strong dependency of segmentation results to the scale parameter, choosing the best value for this parameter, for each class, becomes a main challenge in object-based image analysis. We propose a new framework which employs pixel-based land cover map to estimate the initial scale dedicated to each class. These scales are used to build segmentation scale space (SSS), a hierarchy of image objects. Optimization of SSS, respect to NDVI and DSM values in each super object is used to get the best scale in local regions of image scene. Optimized SSS segmentations are finally classified to produce the final land cover map. Very high resolution aerial image and digital surface model provided by ISPRS 2D semantic labelling dataset is used in our experiments. The result of our proposed method is comparable to those of ESP tool, a well-known method to estimate the scale of segmentation, and marginally improved the overall accuracy of classification from 79% to 80%.

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