1,567 results on '"Object based"'
Search Results
2. Canopy-Height and Stand-Age Estimation in Northeast China at Sub-Compartment Level Using Multi-Resource Remote Sensing Data.
- Author
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Guan, Xuebing, Yang, Xiguang, Yu, Ying, Pan, Yan, Dong, Hanyuan, and Yang, Tao
- Subjects
- *
FOREST management , *REMOTE sensing , *STANDARD deviations , *FOREST surveys , *MIXED forests , *CONIFEROUS forests - Abstract
Stand age is a significant factor when investigating forest resource management. How to obtain age data at a sub-compartment level on a large regional scale conveniently and in real time has become an urgent scientific challenge in forestry research. In this study, we established two strategies for stand-age estimation at sub-compartment and pixel levels, specifically object-based and pixel-based approaches. First, the relationship between canopy height and stand age was established based on field measurement data, which was achieved at the Mao'er Mountain Experimental Forest Farm in 2020 and 2021. The stand age was estimated using the relationship between the canopy height, the stand age, and the canopy-height map, which was generated from multi-resource remote sensing data. The results showed that the validation accuracy of the object-based estimation results of the stand age and the canopy height was better than that of the pixel-based estimation results, with a root mean squared error (RMSE) increase of 40.17% and 33.47%, respectively. Then, the estimated stand age was divided into different age classes and compared with the forest inventory data (FID). As a comparison, the object-based estimation results had better consistency with the FID in the region of the broad-leaved forests and the coniferous forests. In addition, the pixel-based estimation results had better accuracy in the mixed forest regions. This study provided a reference for estimating stand age and met the requirements for stand-age data at the pixel and sub-compartment levels for studies involving different forestry applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. An Artificial Neural Network Combined to Object Oriented Method for Land Cover Classification of High Resolution RGB Remote Sensing Images
- Author
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Baroud, Sohaib, Chokri, Soumia, Belhaous, Safa, Hidila, Zineb, Mestari, Mohammed, Filipe, Joaquim, Editorial Board Member, Ghosh, Ashish, Editorial Board Member, Kotenko, Igor, Editorial Board Member, Prates, Raquel Oliveira, Editorial Board Member, Zhou, Lizhu, Editorial Board Member, Hamlich, Mohamed, editor, Bellatreche, Ladjel, editor, Mondal, Anirban, editor, and Ordonez, Carlos, editor
- Published
- 2020
- Full Text
- View/download PDF
4. Earth Observation and Map-Based Land-Use Change Analysis in the Kulunda Steppe Since the 1950s
- Author
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Hese, S., Kurepina, N., Walde, I., Tsimbalei, Yu. M., Plutalova, T. G., Müller, Lothar, Series Editor, Frühauf, Manfred, editor, Guggenberger, Georg, editor, Meinel, Tobias, editor, Theesfeld, Insa, editor, and Lentz, Sebastian, editor
- Published
- 2020
- Full Text
- View/download PDF
5. Open Remote Sensing Image Classification Using NDVI and Thermal Bands
- Author
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Mastere, Mohamed, Achbun, Abdelkrim, El Fellah, Bouchta, Pisello, Anna Laura, Editorial Board Member, Hawkes, Dean, Editorial Board Member, Bougdah, Hocine, Editorial Board Member, Rosso, Federica, Editorial Board Member, Abdalla, Hassan, Editorial Board Member, Boemi, Sofia-Natalia, Editorial Board Member, Mohareb, Nabil, Editorial Board Member, Mesbah Elkaffas, Saleh, Editorial Board Member, Bozonnet, Emmanuel, Editorial Board Member, Pignatta, Gloria, Editorial Board Member, Mahgoub, Yasser, Editorial Board Member, De Bonis, Luciano, Editorial Board Member, Kostopoulou, Stella, Editorial Board Member, Pradhan, Biswajeet, Editorial Board Member, Abdul Mannan, Md., Editorial Board Member, Alalouch, Chaham, Editorial Board Member, O. Gawad, Iman, Editorial Board Member, Amer, Mourad, Series Editor, Rebai, Noamen, editor, and Mastere, Mohamed, editor
- Published
- 2020
- Full Text
- View/download PDF
6. Canopy-Height and Stand-Age Estimation in Northeast China at Sub-Compartment Level Using Multi-Resource Remote Sensing Data
- Author
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Xuebing Guan, Xiguang Yang, Ying Yu, Yan Pan, Hanyuan Dong, and Tao Yang
- Subjects
object based ,pixel based ,canopy height ,GEDI ,RF algorithm ,Science - Abstract
Stand age is a significant factor when investigating forest resource management. How to obtain age data at a sub-compartment level on a large regional scale conveniently and in real time has become an urgent scientific challenge in forestry research. In this study, we established two strategies for stand-age estimation at sub-compartment and pixel levels, specifically object-based and pixel-based approaches. First, the relationship between canopy height and stand age was established based on field measurement data, which was achieved at the Mao’er Mountain Experimental Forest Farm in 2020 and 2021. The stand age was estimated using the relationship between the canopy height, the stand age, and the canopy-height map, which was generated from multi-resource remote sensing data. The results showed that the validation accuracy of the object-based estimation results of the stand age and the canopy height was better than that of the pixel-based estimation results, with a root mean squared error (RMSE) increase of 40.17% and 33.47%, respectively. Then, the estimated stand age was divided into different age classes and compared with the forest inventory data (FID). As a comparison, the object-based estimation results had better consistency with the FID in the region of the broad-leaved forests and the coniferous forests. In addition, the pixel-based estimation results had better accuracy in the mixed forest regions. This study provided a reference for estimating stand age and met the requirements for stand-age data at the pixel and sub-compartment levels for studies involving different forestry applications.
- Published
- 2023
- Full Text
- View/download PDF
7. Object based attention in visual word processing
- Author
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Revie, Gavin F. and Kamide, Yuki
- Subjects
153.7 ,Cognitive Psychology ,Attention ,Reading ,Object Based ,English - Abstract
This thesis focusses on whether words are treated like visual objects by the human attentional system. Previous research has shown an attentional phenomenon that is associated specifically with objects: this is known as “object based attention” (e.g. Egly, Driver & Rafal, 1994). This is where drawing a participant’s attention (cuing) to any part of a visual object facilitates target detection at non-cued locations within that object. That is, the cue elevates visual attention across the whole object. The primary objective of this thesis was to demonstrate this effect using words instead of objects. The main finding of this thesis is that this effect can indeed be found within English words – but only when they are presented in their canonical horizontal orientation. The effect is also highly sensitive to the type of cue and target used. Cues which draw attention to the “wholeness” of the word appear to amplify the object based effect. A secondary finding of this thesis is that under certain circumstances participants apply some form of attentional mapping to words which respects the direction of reading. Participants are faster (or experience less cost) when prompted to move their attention in accord with reading direction than against. This effect only occurs when the word stimuli are used repeatedly during the course of the experiment. The final finding of this thesis is that both the object based attentional effect and the reading direction effect described above can be found using either real words or a non-lexical stimulus: specifically symbol strings. This strongly implies that these phenomena are not exclusively associated with word stimuli, but are instead associated with lower level visual processing. Nonetheless, it is considered highly likely that these processes are involved in the day to day process of reading.
- Published
- 2015
8. Fine description on the development regularities of channel thick sand bodies.
- Author
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Ding, Fang, Duan, Dongping, Liu, Yinghui, Huang, Xin, Chen, Bo, and Chen, Chen
- Abstract
Channel characterization is very important, but recognizing the channel is difficult in both modern and ancient environments and depends largely on the quality and resolution of the data obtained. In this article, single-well facies analysis, well profile analysis, plane facies analysis, and so on are presented, which rely heavily on core data, well logs, and seismic data. These data have fundamentally changed our understanding of the depositional processes and reservoir distribution of the study area. This paper identified seven period channels based on the above fine geological features. The horizontal wells were put into production in September 2014, and they started to yield water in July 2015. The relation between oil and gas and water underground reservoirs is complicated. It is hard to accurately predict the reservoir parameter distribution between wells. Therefore, this research applied the object-based modeling technology to build a reservoir model, which can effectively depict some geometric characteristics of river, such as channel length and width, and can reflect reservoir heterogeneity between wells. In order to test the accuracy of the model, reserve fitting and production performance fitting were used. The result showed that the established model is true and reliable, and the model can provide three-dimensional geologic model for the later numerical simulation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
9. Assessing the performance of the multi-morphological profiles in urban land cover mapping using pixel based classifiers and very high resolution satellite imagery
- Author
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L.T. Tsoeleng, J. Odindi, P. Mhangara, and O. Malahlela
- Subjects
Pixel based ,Object based ,Morphological techniques ,High-resolution satellite imagery ,Science - Abstract
Improved spatial and spectral resolution from recent sensor advancements provides opportunities for detailed and enhanced accuracies in the classification of heterogeneous urban landscapes. However, to date, such classifications have remained a challenge for most pixel based techniques. Whereas object based techniques have proved effective in classifying heterogeneous urban landscapes, by providing an effective framework for analysis of high spatial resolution images, challenges such as under and over-segmentation and non-robust statistical estimation impede their optimum performance in the often complex urban landscapes. Therefore, it is imperative that an effective classification approach is identified for effective utilisation of both spatio-spectral characteristics of image objects. Morphological techniques, especially multi-morphological profiles (MMP), provide an effective framework for the analysis of both spectral and spatial information from very high-resolution satellite imagery by performing image analysis based on features such as geometric, texture and contrast. In this study, using Support Vector Machine (SVM) and Maximum Likelihood (ML) classification algorithms, we compare the classification accuracies based on MMP as feature vector against those without MMP as a feature vector. Results from this study indicate that the use of MMP as a feature vector produced significantly higher classification accuracies of 84.8% and 82.2%, compared to 75.77% and 77.6% without MMP as a feature vector for SVM and ML, respectively. The study concludes that MMP can be used as a feature vector to increase the classification accuracy of a heterogeneous urban land use land cover.
- Published
- 2020
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10. A Poisson Random Walk Model of Response Times.
- Author
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Blurton, Steven P., Kyllingsbæk, Søren, Nielsen, Carsten S., and Bundesen, Claus
- Subjects
- *
RANDOM walks , *INVESTIGATIONS - Abstract
Based on the simple what first comes to mind rule, the theory of visual attention (TVA; Bundesen, 1990) provides a comprehensive account of visual attention that has been successful in explaining performance in visual categorization for a variety of attention tasks. If the stimuli to be categorized are mutually confusable, a response rule based on the amount of evidence collected over a longer time seems more appropriate. In this paper, we extend the idea of a simple race to continuous sampling of evidence in favor of a certain response category. The resulting Poisson random walk model is a TVA-based response time model in which categories are reported based on the amount of evidence obtained. We demonstrate that the model provides an excellent account for response time distributions obtained in speeded visual categorization tasks. The model is mathematically tractable, and its parameters are well founded and easily interpretable. We also provide an extension of the Poisson random walk to any number of response alternatives. We tested the model in experiments with speeded and nonspeeded binary responses and a speeded response task with multiple report categories. The Poisson random walk model agreed very well with the data. A thorough investigation of processing rates revealed that the perceptual categorizations described by the Poisson random walk were the same as those obtained from TVA. The Poisson random walk model could therefore provide a unifying account of attention and response times. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. Performance analysis of an efficient object-based schema oriented data storage system handling health data.
- Author
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Mondal, Anindita Sarkar, Neogy, Sarmistha, Mukherjee, Nandini, and Chattopadhyay, Samiran
- Abstract
Object-based cloud storage system has an important role in handling big data. All available cloud storage systems deal with scalability, reliability or durability issues. However, there is lack of work addressing data variety. In a previous paper, a basic architecture of an object-based schema oriented data storage system has been proposed which stores data in an encapsulated way. The system comprises account layer, container layer, object layer, database layer and schema layer. In this paper, the architecture proposed in our previous paper has been elaborated. For example, the communication protocols of the proposed system are explained. Moreover, this architecture is realized to test its effectiveness on health data in terms of query execution performance and flexibility on the basis of four different queries of database computation (e.g., append, read, aggregate and delete). The result set are collected on three types of datasets (table, document, file) taken from healthcare scenario. Each type of dataset consists of four different sets of data records. The performance is compared with Amazon S3 (i.e., bucket oriented object-based data storage system) and Microsoft Azure (i.e., account-container oriented object-based data storage system). Flexibility property is also analyzed with respect to these three database operations (i.e., READ, WRITE and DELETE) on three types of experimental datasets (table, document, file) with Amazon S3. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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12. Object based building footprint detection from high resolution multispectral satellite image using K-means clustering algorithm and shape parameters.
- Author
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Gavankar, Nitin Laxmanrao and Ghosh, Sanjay Kumar
- Subjects
- *
K-means clustering , *REMOTE-sensing images , *MULTISPECTRAL imaging , *IMAGE analysis , *IMAGE processing , *EXTRACTION techniques , *FOOTPRINTS - Abstract
Object-based image analysis (OBIA) has been a new area of research in satellite image processing applications, since it improves the quality of information acquisition about geospatial objects and also enables to add spatial and contextual information to the objects of interest. The extraction of buildings from High Resolution Satellite (HRS) image in an urban scenario has been an intricate problem due to their different size, shape, varying rooftop textures and low contrast between building and surrounding region. In this study, a new object-based automatic building extraction technique has been proposed to extract building footprints from HRS pan sharpened IKONOS multispectral image. The study is mainly emphasizing on obtaining optimal values for segmentation parameters, shape parameters, and defining rule set to extract buildings and eliminate misclassified other urban features. The suitability of the technique has been judged using different indicators, such as, completeness, correctness and quality. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
13. Object-based forest gaps classification using airborne LiDAR data.
- Author
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Mao, Xuegang and Hou, Jiyu
- Abstract
Object-based classification differentiates forest gaps from canopies at large regional scale by using remote sensing data. To study the segmentation and classification processes of object-based forest gaps classification at a regional scale, we sampled a natural secondary forest in northeast China at Maoershan Experimental Forest Farm. Airborne light detection and ranging (LiDAR; 3.7 points/m
2 ) data were collected as the original data source and the canopy height model (CHM) and topographic dataset were extracted from the LiDAR data. The accuracy of object-based forest gaps classification depends on previous segmentation. Thus our first step was to define 10 different scale parameters in CHM image segmentation. After image segmentation, the machine learning classification method was used to classify three kinds of object classes, namely, forest gaps, tree canopies, and others. The common support vector machine (SVM) classifier with the radial basis function kernel (RBF) was first adopted to test the effect of classification features (vegetation height features and some typical topographic features) on forest gap classification. Then the different classifiers (KNN, Bayes, decision tree, and SVM with linear kernel) were further adopted to compare the effect of classifiers on machine learning forest gaps classification. Segmentation accuracy and classification accuracy were evaluated by using Möller's method and confusion metrics, respectively. The scale parameter had a significant effect on object-based forest gap segmentation and classification. Classification accuracies at different scales revealed that there were two optimal scales (10 and 20) that provided similar accuracy, with the scale of 10 yielding slightly greater accuracy than 20. The accuracy of the classification by using combination of height features and SVM classifier with linear kernel was 91% at the optimal scale parameter of 10, and it was highest comparing with other classification classifiers, such as SVM RBF (90%), Decision Tree (90%), Bayes (90%), or KNN (87%). The classifiers had no significant effect on forest gap classification, but the fewer parameters in the classifier equation and higher speed of operation probably lead to a higher accuracy of final classifications. Our results confirm that object-based classification can extract forest gaps at a large regional scale with appropriate classification features and classifiers using LiDAR data. We note, however, that final satisfaction of forest gap classification depends on the determination of optimal scale (s) of segmentation. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
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14. Evaluating the Close Range Hyperspectral Data for Feature Identification and Mapping.
- Author
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Kumar, Vinay, Mohan, Anand, Agarwal, Shefali, and Siddiqui, Asfa
- Abstract
Exploring enhanced spectral information embedded in hyperspectral remote sensing (HSRS) datasets is a frontier field of remote sensing and bears the potential of detailed information extraction. This study involves the utility of high spatial resolution HSRS data for enhanced feature identification and classification based on spatial and spectral information. For the purpose of the study, close range hyperspectral dataset was used that was acquired using HySpex VNIR-1800 camera developed by Norsk Elektro Optikk. The image was converted to surface reflectance, and classification was employed on a total of 9 land cover features identified. Pixel-based classification was performed using support vector machine and compared with the classification result of object-based classification. For performing object-based classification, multiresolution segmentation along with fuzzy rule-based classifier was applied on the optimal spectral bands and minimum noise fraction components generated from the HSRS dataset. The results indicate an enhanced capability of object-based classification (92.5%) over pixel-based classification (71.24%). It was observed that the resultant classified images show misclassification of natural features in pixel-based classified output. Object-based classification approach has advantage over other approach in terms of accuracy with Kappa score of 0.89 over pixel-based kappa score of 0.62. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
15. Object-Based Method for Urban Extraction through Using Quick Bird Satellite Imagery, LiDAR Data and Digital Urban Geomatics Techniques
- Author
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Noor Hashim Hamed
- Subjects
svm ,Computer science ,business.industry ,Geomatics ,urban extraction ,ecognition software ,Object based ,General Medicine ,Engineering (General). Civil engineering (General) ,rf ,Extraction (military) ,Satellite imagery ,Lidar data ,TA1-2040 ,business ,ann ,lidar ,Remote sensing - Abstract
Urban extraction mapping has become increasingly important in recent years and particularity extraction urban features based on remotely sensed data such as highresolution imagery and LiDAR data. Though the researchers used the high spatial resolution image to extract urban area but he methods are still complex and still there are challenges associated with combining data that were acquired over differing time periods using inconsistent standards. So, this study will focus on the extraction of urban area based on an object-based classification method with integration of Quickbird satellite image and digital surface elevation (DSM) extracted from LiDAR data for the Rusafa city of Baghdad, Iraq. All the processes were done in eCognition and ArcGIS software for feature extraction and mapping, respectively. The overall methodological steps proposed in this research for the extraction of urban area using object-based method. In addition of that both the image data and LiDAR-derived DSM were integrated based on the eCognition software for extraction urban map of Rusafa city, Baghdad. Finally, the results indicated that the Artificial Neural Networks (ANN) model achieved the highest training and testing accuracies and performed the best compared to RF and Support Vector Machines (SVM) methods. And also, the results showed that the Artificial Neural Networks (ANN) had capability to extract the boundaries of the buildings and other urban features more accurately than the other two methods. This could be interpreted as the Artificial Neural Networks (ANN) model can learn complex features by the optimization process of the model and its multi-level feature extraction property
- Published
- 2022
16. Semantic Segmentation for Remote Sensing Images Using Pyramid Object-Based Markov Random Field With Dual-Track Information Transmission
- Author
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Hongtai Yao, Bowen Li, Gong Li, Le Zhao, Meng Tian, and Wang Xianpei
- Subjects
Information transmission ,Markov random field ,Computer science ,business.industry ,Track (disk drive) ,Object based ,DUAL (cognitive architecture) ,Geotechnical Engineering and Engineering Geology ,Remote sensing (archaeology) ,Pyramid ,Segmentation ,Computer vision ,Artificial intelligence ,Electrical and Electronic Engineering ,business - Published
- 2022
17. Automatic Type Deduction
- Author
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Slobodan Dmitrović
- Subjects
Computer science ,business.industry ,Specifier ,Object based ,Initialization ,Computer vision ,Artificial intelligence ,Type (model theory) ,Object (computer science) ,business - Abstract
We can automatically deduce the type of an object using the auto specifier. The auto specifier deduces the type of an object based on the object’s initializer type.
- Published
- 2023
18. A bit-object-based method for mining maximum frequent patterns in intensive cloud computing data
- Author
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Li Yang, Chen Chen, and Xunan Jia
- Subjects
Bit (horse) ,Computer engineering ,Artificial Intelligence ,Computer Networks and Communications ,Computer science ,business.industry ,Object based ,Cloud computing ,business ,Software - Abstract
In order to overcome the problems of poor timeliness and low accuracy of mining existing in traditional methods, this paper designs a bit-object based maximum frequent pattern mining method for intensive cloud computing data. After judging the support number according to the bit object of the maximum frequent pattern, the intensive cloud computing data is accurately collected according to the difference between the load value of cloud data and the true value of load, so as to improve the accuracy of subsequent mining results, and then the maximum frequent pattern of data is accurately mined by combining the bit object. Experimental results show that the maximum time to generate mining results is only 4.6 s, the maximum bit error rate of output results is only 7%, and the maximum memory occupancy is only 3.90%. The above results show that this method is more suitable for practical excavation.
- Published
- 2021
19. Optimized unsupervised CORINE Land Cover mapping using linear spectral mixture analysis and object-based image analysis
- Author
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Alexander Parra Uzcátegui, Silvia Ruggeri, Yeison Alberto Garcés-Gómez, and Vladimir Henao-Cespedes
- Subjects
Land cover ,QB275-343 ,OBIA ,Linear spectral mixture analysis ,business.industry ,Computer science ,Multispectral image ,Object based ,Pattern recognition ,Remote sensing ,Object (computer science) ,High mountain ,Image (mathematics) ,LSMA ,General Earth and Planetary Sciences ,Artificial intelligence ,Moorland ,business ,Landsat ,Geodesy ,Reliability (statistics) - Abstract
In this paper, the approach Linear Spectral Mixture Analysis and Object-Based Image Analysis (LSMA + OBIA) and Iterative Self-Organizing Data Analysis Technique and Object-Based Image Analysis (ISODATA + OBIA) are evaluated, for optimizing land cover mapping in high mountain areas from Landsat-8 multispectral images. Both approaches are applied to generate in a semiautomatic and unsupervised way a land cover map of the Santurban-Berlin moorland, located in Colombia as a case study to carry out the evaluation. It has been found that LSMA + OBIA allows the generation of a land cover classification with a maximum global reliability of 88% compared to a reliability of 79% with ISODATA + OBIA.
- Published
- 2021
20. Pixel-based vs. object-based anthropogenic impervious surface detection: driver for urban-rural thermal disparity in Faridabad, Haryana, India
- Author
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Kousik Midya, Sultan Singh, Swagata Ghosh, and Sunil Kumar
- Subjects
Geography, Planning and Development ,Thermal ,Pixel based ,Object based ,Impervious surface ,Environmental science ,Water Science and Technology ,Remote sensing - Published
- 2021
21. Using object-based image analysis to detect laughing gull nests
- Author
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Benjamin F. Martini and D. A. Miller
- Subjects
biology ,business.industry ,TEC ,ECognition ,Feature extraction ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Object based ,Wildlife ,biology.organism_classification ,Aerial imagery ,Geography ,Remote sensing (archaeology) ,Laughing gull ,General Earth and Planetary Sciences ,Computer vision ,ComputingMethodologies_GENERAL ,Artificial intelligence ,business - Abstract
Remote sensing has long been used to study wildlife; however, manual methods of detecting wildlife in aerial imagery are often time-consuming and prone to human error, and newer computer vision tec...
- Published
- 2021
22. An improved Yolov5 real-time detection method for small objects captured by UAV
- Author
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Chenfan Sun, Maocai Wang, Yangyang Zhang, Zhiliang Zhang, Jinhui She, Yong Sun, and Wei Zhan
- Subjects
Computer science ,Real-time computing ,Object based ,Detection performance ,Computational intelligence ,Geometry and Topology ,State (computer science) ,Software ,Drone ,Object detection ,Theoretical Computer Science - Abstract
The object detection algorithm is mainly focused on detection in general scenarios, when the same algorithm is applied to drone-captured scenes, and the detection performance of the algorithm will be significantly reduced. Our research found that small objects are the main reason for this phenomenon. In order to verify this finding, we choose the yolov5 model and propose four methods to improve the detection precision of small object based on it. At the same time, considering that the model needs to be small in size, speed fast, low cost and easy to deploy in actual application, therefore, when designing these four methods, we also fully consider the impact of these methods on the detection speed. The model integrating all the improved methods not only greatly improves the detection precision, but also effectively reduces the loss of detection speed. Finally, based on VisDrone-2020, the mAP of our model is increased from 12.7 to 37.66%, and the detection speed is up to 55FPS. It is to outperform the earlier state of the art in detection speed and promote the progress of object detection algorithms on drone platforms.
- Published
- 2021
23. SEMI-AUTOMATED DELINEATION OF INFORMAL SETTLEMENT STRUCTURES FROM DRONE RGB IMAGERY USING OBJECT-BASED IMAGE ANALYSIS
- Author
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K. A. P. Vergara, A. C. Blanco, E. N. B. Idago, and R. A. B. Rivera
- Subjects
Technology ,Computer science ,business.industry ,Settlement (structural) ,Object based ,Engineering (General). Civil engineering (General) ,Drone ,Image (mathematics) ,TA1501-1820 ,RGB color model ,Computer vision ,Applied optics. Photonics ,Artificial intelligence ,TA1-2040 ,business - Abstract
With the problem of informal settlements in the Philippines, mapping such areas is the first step towards improvement. Object-based image analysis (OBIA) has been a powerful tool for mapping and feature extraction, especially for high-resolution datasets. In this study, an informal settlement area in UP Diliman, Quezon City was chosen to be the subject site, where individual informal settlement structures (ISS) were delineated and estimated using OBIA. With the help of photogrammetry and image enhancement techniques, derivatives such as elevation model and orthophotos were produced for easier interpretation. An initial rule-set was developed to remove all non-ISS features from the base image–utilizing spectral values and thematic layers as main classifiers. This classification technique yielded a 94% accuracy for non-ISS class, and 92% for the possible ISS class. Another rule-set was then developed to delineate individual ISS based on the texture and elevation model of the area, which paved the way for the estimation of ISS count. To test the robustness of the methodology developed, the estimation results were compared to the manual count obtained through an online survey form, and the classification and delineation results were assessed through overall and individual quality checks. The estimation yielded a relative accuracy of 60%, which came from the delineation rate of 63%. On the other hand, delineation accuracy was calculated through area-based and number-based measures, yielding 58% and 95%, respectively. Issues such as noisy elevation models and physical limitations of the area and survey done affected the accuracy of the results.
- Published
- 2021
24. PENETAPAN TEMPAT KHUSUS PARKIR DI KAWASAN OBJEK WISATA KULINER CIMANUK INDRAMAYU BERDASARKAN PERATURAN DAERAH NOMOR 16 TAHUN 2017 PENYELENGGARAAN PERPARKIRAN DI KABUPATEN INDRAMAYU
- Author
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Syamsul Bahri Siregar and Suchi Susanti Dwi Sonjaya
- Subjects
Descriptive statistics ,Tourist attraction ,Parking area ,Parking lot ,Object based ,Parking space ,Business ,Environmental planning ,Regional income ,Research method - Abstract
The increasing use of private transportation, now more and more public places that provide vehicle storage facilities in their area. This vehicle storage is better known as parking by the community. In Article 1 No. 14 of the Regional Regulation of Indramayu Regency Number 16 of 2017 concerning Parking Management which states that parking can be interpreted as a state of stopping or not moving for a while and being abandoned by the driver. The existence of a parking lot is very helpful for the community, especially for those who have vehicles, you can imagine if there is no parking space. In the concept of this scientific paper using the normative juridical research method. As well as using data collection techniques carried out using descriptive analysis techniques, with secondary data sources, which include primary legal materials such as laws and regulations relating to the Regional Regulation of Indramayu Regency Number 16 of 2017 concerning Parking Management. The purpose of this study is to find out where special parking spaces can be established in the Cimanuk Indramayu culinary tourism object based on Regional Regulation Number 16 of 2017 concerning Parking Implementation and to find out the management of parking special areas in Indramayu based on Regional Regulation of Indramayu Regency Number 16 of 2017 concerning Parking Implementation. The results of this study indicate that in the implementation of Parking Management in Indramayu Regency, it has been regulated in the Regional Regulation of Indramayu Regency Number 16 of 2017 concerning Parking Management and has been in accordance with applicable regulations. But in its implementation, this is not like that because in implementation, the parking lot is a utility, only useful for local governments for regional income but for the community it is very burdensome.
- Published
- 2021
25. Improved object-based convolutional neural network (IOCNN) to classify very high-resolution remote sensing images
- Author
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Keqi Zhou, Dongping Ming, Zhenfeng Shao, Xianwei Lv, Chunyuan Diao, and Chengzhuo Tong
- Subjects
Very high resolution ,Computer science ,Remote sensing (archaeology) ,Object based ,General Earth and Planetary Sciences ,Land cover ,Convolutional neural network ,Remote sensing ,Task (project management) - Abstract
The land cover classification of very high-resolution (VHR) remote sensing images is a challenging task. VHR images depict many complex objects with various shapes in complicated contexts. The deep...
- Published
- 2021
26. Object-Based Rule Sets and Its Transferability for Building Extraction from High Resolution Satellite Imagery.
- Author
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Attarzadeh, Reza and Momeni, Mehdi
- Abstract
With the advent of high spatial resolution satellite imagery, automatic and semiautomatic building extractions have turned into one of the outstanding research topics in the field of remote sensing and machine vision. To this date, various algorithms have been presented for extracting the buildings from satellite images. Such methods lend their bases to diverse criteria such as radiometric, geometric, edge detection, and shadow. In this paper, a novel object based approach has been proposed for automatic and robust detections as well as extraction of the building in high spatial resolution images. To fulfill this, we simultaneously made use of both stable and variable features. While the former can be derived from inherent characteristics of the buildings, the latter is extracted using a feature analysis tool. In addition, a novel perspective has been recommended to boost the automation degree of the segmentation part in the object based analysis of remote sensing imagery. The proposed method was applied to a QuickBird imagery of an urban area in Isfahan city and the results of the quantitative evaluation demonstrated that the proposed method could yield promising results. Moreover, in another section of this study, for assessing the algorithm transferability, the rule set was implemented to a part of the WorldView image of Yazd city, proving that the proposed approach is capable of transferability in different types of case studies. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
27. Spectral indices based object oriented classification for change detection using satellite data.
- Author
-
Bhatt, Abhishek, Ghosh, S. K., and Kumar, Anil
- Abstract
Change detection, using remotely sensed data can be utilized in a diversified way such as, land use and cover analysis, forest or vegetation assessment, and flood monitoring. The aim of this study is to develop a methodology for change detection in highly urbanized areas, using time-series satellite imagery. This paper analyzes the effectiveness of the object oriented classification over unsupervised algorithms such as
k -means for the purpose of change detection. The study area selected is, National Capital Territory of Delhi, which is a good representative of the urban agglomeration conditions in the Asian region. A time series of Landsat 5 (TM) and Landsat 8 (OLI) imageries for the duration of 1993-2014, have been acquired in order to represent the wide range of pattern variation. This study uses three spectral indices namely, Normalized Difference Built-up Index to characterize built-up area, Modified Normalized Difference Water Index to signify open water and Modified Soil Adjusted Vegetation Index to symbolize green vegetation. Further, this study employs object-based environment that separates similar pixels spatially and spectrally at different scales and assign information class to segmented objects. Results recommends the use of OBIA as a semi-automated tool for classification of remotely sensed satellite data. Moreover, using OBIA along with traditional spectral indices, for the classification, provides dimensionality reduction. Moreover, such a method produces classified map which have great correspondence with reality, reflects in high accuracies that were achieved for classes like built-up. The statistics indicated that the classification with object oriented paradigm achieved an overall accuracy of up to 90.1 %, which is far better as compared to automated unsupervised clustering algorithm, such ask -means. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
28. Parcel-Based Active Learning for Large Extent Cultivated Area Mapping.
- Author
-
Amor, Ines Ben Slimene Ben, Chehata, Nesrine, Bailly, Jean-Stephane, Farah, Imed Riadh, and Lagacherie, Philippe
- Abstract
This paper focuses on agricultural land cover mapping at a high-resolution scale and over large areas from an operational point of view and from a high-resolution monodate image. In this context, training data are assumed to be collected by successive journeys of field surveys and, thus, are very limited. Supervised learning techniques are generally used, assuming that the classes distribution is constant over the whole image. However, in practice, a data shift often occurs on large areas due to various acquisition conditions. To alleviate these issues, active learning (AL) techniques define an efficient training set by iteratively adapting it through adding the most informative unlabeled instances. They can improve the classification process efficiency while keeping a limited training dataset. The novelty in this paper is the application of AL techniques on multispectral images for agricultural land cover mapping, using field sampling instead of pixel sampling, which is rarely done in the literature. Besides, we proposed a parcel-based AL scheme that is suitable for an operational land cover mapping in cultivated areas since the parcel is an agricultural unit and field observations are processed at parcel scale. Random forests classifier was used. Results were processed on a 6 m multispectral Spot6 image over a 35 km $^2$ Mediterranean cultivated area, in Lebna Catchment, north eastern Tunisia. The contribution of AL techniques was assessed with comparison to a random and stratified random strategies for sampling new instances. For iterative sample selection, two criteria are used and often coupled: uncertainty and diversity. For diversity metric, a new clustering-based metric was proposed based on a mean-shift clustering, which improved the classification accuracy. AL techniques showed to be efficient with complex data and fine land cover legend improving random-based selection up to 10%. Besides, the maximum of classification accuracy is reached using mean-shift breaking ties metric in just 5-day field survey, i.e., 30 days less compared to the random selection. Finally, results showed that the finer the definition of land cover classes, the more crucial is the choice of AL metrics. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
29. OSSIM: An Object-Based Multiview Stereo Algorithm Using SSIM Index Matching Cost.
- Author
-
Liang Fei, Li Yan, Changhai Chen, Zhiyun Ye, and Jiantong Zhou
- Subjects
- *
IMAGE reconstruction , *ALGORITHMS , *LIDAR , *SIGNAL-to-noise ratio , *DEPTH maps (Digital image processing) , *LOCUS (Mathematics) - Abstract
Multiview stereo (MVS) is a crucial process in image-based automatic 3-D reconstruction and mapping applications. In a dense matching process, the matching cost is generally computed between image pairs, making the efficiency low due to the large number of stereo pairs. This paper presents a novel object-based MVS algorithm using structural similarity (SSIM) index matching cost in a coarse-to-fine workflow. As far as we know, this is the first time SSIM index is introduced to calculate the matching cost of MVS applications. In contrast to classical stereo methods, the proposed object-based structural similarity (OSSIM) method computes only a depth map for each image. Thus, the efficiency can be greatly improved when the overlap between images is large. To obtain an optimized depth map, the winner-take-all and semi-global matching strategies are implemented. Moreover, an object-based multiview consistency checking strategy is also proposed to eliminate wrong matches and perform pixelwise view selection. The proposed method was successfully applied on a close-range Fountain-P11 data set provided by EPFL and aerial data sets of Vaihingen and Zürich by the ISPRS. Experimental results demonstrate that the proposed method can deliver matches at high completeness and accuracy. For the Vaihingen data set, the correctness and completeness rate were 71.12% and 95.99% with an RMSE of 2.8 GSD. For the Foutain-P11 data set, the proposed method outperformed the other existing methods with the ratio of pixels less than 2 cm. Extensive comparison using Zürich data set shows that it can derive results comparable to the state-of-the-art software (PhotoScan, Pix4d, and Smart3D) in urban buildings areas. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
30. Object-based machine learning approach for soybean mapping using temporal sentinel-1/sentinel-2 data
- Author
-
Varun Pandey, C. S. Murthy, Karun Kumar Choudhary, and Mamta Kumari
- Subjects
Computer science ,business.industry ,Geography, Planning and Development ,Object based ,Context (language use) ,Monsoon ,Machine learning ,computer.software_genre ,Random forest ,Support vector machine ,Artificial intelligence ,Extreme gradient boosting ,business ,computer ,Period (music) ,Water Science and Technology - Abstract
Soybean mapping in Indian context is challenging owing to its short growing period coinciding with the monsoon clouds, inter-cropping and smallholders’ land. This study proposes an approach for map...
- Published
- 2021
31. PEMETAAN LAHAN DAN KOMODITAS PERTANIAN BERBASIS WEBGIS DI KABUPATEN OKU TIMUR
- Author
-
Andi Santoso and Muhammad Nasir
- Subjects
education.field_of_study ,Geographic information system ,business.industry ,Agroforestry ,Population ,Object based ,Distribution (economics) ,Livelihood ,language.human_language ,Indonesian ,Geography ,Agricultural land ,Agriculture ,language ,business ,education - Abstract
The potential of agricultural land in Indonesia is still very wide so that the agricultural sector is still one of the incomes for most Indonesian people. The agricultural land sector is widely distributed in various regions in Indonesia, one of which is in the East Oku Regency, South Sumatra. As an agricultural area, the majority of the population in East Oku Regency choose their livelihood as farmers. However, the distribution of agricultural land has not been mapped, which can provide information about the location of agricultural land, especially in East Oku Regency. In this study, the development of a web-based Agricultural Land Geographic Information System in East OKU Regency was carried out. The geographic information system built can display information in the form of spatial and non-spatial data that describes an object based on the state of the earth. The method used in making this system is object-oriented method. With the development of this Geographic Information System, it is hoped that it will be able to provide information for the community about the distribution of the location and area of agricultural land, especially in the East OKU Regency area.
- Published
- 2021
32. Drawing with Art‐Well‐Being: Intergenerational Co‐Creation with Seniors, Children and the Living Museum
- Author
-
Geraldine Burke, Laura Alfrey, Clare Hall, and Justen O’Connor
- Subjects
Arts and Humanities (miscellaneous) ,Visual Arts and Performing Arts ,Well-being ,Co-creation ,Object based ,Sociology ,Visual arts education ,Education ,Visual arts - Published
- 2021
33. Timed neural network using object-based model of neurons for shortest path problem
- Author
-
Annamalai Murugan and Ramadurai Krishnan
- Subjects
Quantitative Biology::Neurons and Cognition ,Artificial neural network ,Computer Networks and Communications ,business.industry ,Computer science ,Applied Mathematics ,Work (physics) ,Object based ,Construct (python library) ,Object (computer science) ,Computer Science Applications ,Set (abstract data type) ,Computational Theory and Mathematics ,Artificial Intelligence ,Shortest path problem ,Graph (abstract data type) ,Artificial intelligence ,Electrical and Electronic Engineering ,business ,Information Systems - Abstract
The objective of this work is to construct a cooperative neural network where every neuron is a minimal computational processing routine. This paper shows the implementation of such a network for solving the familiar shortest path problem without compromising the objective set for the Object-Based Model (OBM). This paper also throws light on biological observations about the relationship between the time and functioning of a brain. Further, this problem maps the distance/costs in a graph into time and uses it to be the activation time of a neural routine. The cooperative functioning of such neurons producing the result for the shortest path problem is explained with its algorithm. The successful functioning of the implementation of the algorithm is demonstrated with suitable timing diagrams. The theoretical analysis of the algorithm is also provided to show why this model can be considered as an adaptive neural network.
- Published
- 2021
34. REVISITING THE DEMOCRATIC REPUBLIC OF THE CONGO STRATIFICATION MAP FOR THE YEAR 2000 USING CLOUD-BASED COMPOSITING AND OBJECT-BASED CLASSIFICATION ALGORITHMS
- Author
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Wilfred Kombe Ibey and Jean-Paul Kibambe Lubamba
- Subjects
Statistical classification ,Compositing (democracy) ,business.industry ,Computer science ,Object based ,Cloud computing ,Data mining ,Cloud-Based Satellite Image Processing Median luminance Best Pixel Landsat Time Series Stratification Maps ,computer.software_genre ,business ,computer ,Stratification (mathematics) - Abstract
National stratification maps are essential to improve forest management systems. For the Democratic Republic of the Congo, the existing maps derived from remote sensing techniques do not allow an optimal representation of the diverse land cover classes constituting the national stratification scheme. This situation is inherent to the cloud persistence, the seasonality effects and the spatial resolution of the input satellite imagery used that is not always adequate for the discrimination of certain land cover classes. This paper explores a cloud-based median luminance best pixel approach to obtain a cloud-free mosaic of optimal quality. The mosaic produced has necessitated nearly 2,500 Landsat scenes and a following object-based classification enabled the generation of a stratification map for the year 2000 according to the national stratification theme. A stratified random sampling approach that required 1,141 reference samples allowed estimating the map accuracy at 79.32%. Land cover classes areas computed using standard good practices recommendations to estimate land areas indicated that the dense moist forest area was about 158,810,975 ± 7,460,671 ha representing 68.40% ± 3.21% of the country area. Thanks to the free, user-friendly and cloud-based platforms for satellite images processing, the methodology implemented is easily replicable for other tropical countries.  
- Published
- 2021
35. Google Earth Engine for large-scale land use and land cover mapping: an object-based classification approach using spectral, textural and topographical factors
- Author
-
Hossein Shafizadeh-Moghadam, Seyed Kazem Alavipanah, Qihao Weng, and Morteza Khazaei
- Subjects
Climate zones ,Watershed management ,Land use ,Object based ,General Earth and Planetary Sciences ,Land cover ,Structural basin ,Scale (map) ,Cartography ,Geology - Abstract
Mapping the distribution and type of land use and land cover (LULC) is essential for watershed management. The Tigris-Euphrates basin is a transboundary region in the Middle East shared between six...
- Published
- 2021
36. Object‐based large‐scale terrain classification combined with segmentation optimization and terrain features: A case study in China
- Author
-
Norbert Pfeifer, Kai Liu, Wufan Zhao, Jiaming Na, Guoan Tang, and Hu Ding
- Subjects
Scale (ratio) ,Computer science ,Terrain classification ,business.industry ,Object based ,General Earth and Planetary Sciences ,Computer vision ,Segmentation ,Terrain ,Artificial intelligence ,business - Published
- 2021
37. A Scale Sequence Object-based Convolutional Neural Network (SS-OCNN) for crop classification from fine spatial resolution remotely sensed imagery
- Author
-
Ce Zhang, Xiaohui Ding, Huapeng Li, Peter M. Atkinson, Shuqing Zhang, and Yong Zhang
- Subjects
Sequence ,Contextual image classification ,Computer science ,business.industry ,Object based ,Pattern recognition ,Convolutional neural network ,Computer Science Applications ,General Earth and Planetary Sciences ,Artificial intelligence ,business ,Scale (map) ,Image resolution ,Software - Abstract
The highly dynamic nature of agro-ecosystems in space and time usually leads to high intra-class variance and low inter-class separability in the fine spatial resolution (FSR) remotely sensed imagery. This makes traditional classifiers essentially relying on spectral information for crop mapping from FSR imagery an extremely challenging task. To mine effectively the rich spectral and spatial information in FSR imagery, this paper proposed a Scale Sequence Object-based Convolutional Neural Network (SS-OCNN) that classifies images at the object level by taking segmented objects (crop parcels) as basic units of analysis, thus, ensuring that the boundaries between crop parcels are delineated precisely. These segmented objects were subsequently classified using a CNN model integrated with an automatically generated scale sequence of input patch sizes. This scale sequence can fuse effectively the features learned at different scales by transforming progressively the information extracted at small scales to larger scales. The effectiveness of the SS-OCNN was investigated using two heterogeneous agricultural areas with FSR SAR and optical imagery, respectively. Experimental results revealed that the SS-OCNN consistently achieved the most accurate classification results. The SS-OCNN, thus, provides a new paradigm for crop classification over heterogeneous areas using FSR imagery, and has a wide application prospect.
- Published
- 2021
38. Potential of Pléiades and Radarsat-2 Data for Mapping Plastic-Mulched Farmland Using Object-Based Image Analysis
- Author
-
Chen Zhongxin, Hasi Tuya, Li Fei, and Li Zhenwang
- Subjects
Agricultural development ,Object based ,General Earth and Planetary Sciences ,Environmental science ,Spatial distribution ,Pleiades ,Image (mathematics) ,Remote sensing - Abstract
The increasing area of Plastic-Mulched Farmland (PMF) is aggravating the conflict between agricultural development and environmental protection. The spatial distribution of PMF requires an effectiv...
- Published
- 2021
39. An object-based graph model for unsupervised change detection in high resolution remote sensing images
- Author
-
Junzheng Wu, Han Zhang, Weiping Ni, Biao Li, and Yao Qin
- Subjects
business.industry ,Computer science ,Remote sensing (archaeology) ,Object based ,General Earth and Planetary Sciences ,High resolution ,Computer vision ,Artificial intelligence ,business ,Object (computer science) ,Graph model ,Change detection ,Image (mathematics) - Abstract
The difference image that represents the change levels is pivotal in unsupervised change detection tasks. An object-based graph model is proposed in this paper to generate more reliable difference ...
- Published
- 2021
40. Large-Sample Application of Radar Reflectivity Object-Based Verification to Evaluate HRRR Warm-Season Forecasts
- Author
-
David D. Turner and Jeffrey D. Duda
- Subjects
Atmospheric Science ,Meteorology ,Weather forecasting ,Object based ,Environmental science ,computer.software_genre ,Radar reflectivity ,Warm season ,computer ,Large sample - Abstract
The Method of Object-based Diagnostic Evaluation (MODE) is used to perform an object-based verification of approximately 1400 forecasts of composite reflectivity from the operational HRRR during April–September 2019. In this study, MODE is configured to prioritize deep, moist convective storm cells typical of those that produce severe weather across the central and eastern United States during the warm season. In particular, attributes related to distance and size are given the greatest attribute weights for computing interest in MODE. HRRR tends to overforecast all objects, but substantially overforecasts both small objects at low-reflectivity thresholds and large objects at high-reflectivity thresholds. HRRR tends to either underforecast objects in the southern and central plains or has a correct frequency bias there, whereas it overforecasts objects across the southern and eastern United States. Attribute comparisons reveal the inability of the HRRR to fully resolve convective-scale features and the impact of data assimilation and loss of skill during the initial hours of the forecasts. Scalar metrics are defined and computed based on MODE output, chiefly relying on the interest value. The object-based threat score (OTS), in particular, reveals similar performance of HRRR forecasts as does the Heidke skill score, but with differing magnitudes, suggesting value in adopting an object-based approach to forecast verification. The typical distance between centroids of objects is also analyzed and shows gradual degradation with increasing forecast length.
- Published
- 2021
41. Detection of Potential Vernal Pools on the Canadian Shield (Ontario) Using Object-Based Image Analysis in Combination with Machine Learning
- Author
-
Patricia Chow-Fraser and Nick Luymes
- Subjects
geography ,geography.geographical_feature_category ,business.industry ,Shield ,Environmental resource management ,Object based ,General Earth and Planetary Sciences ,Environmental science ,Ecosystem ,Wetland ,Sensitivity (control systems) ,business - Abstract
Vernal pools are small, temporary, forested wetlands of ecological importance with a high sensitivity to changing climate and land-use patterns. These ecosystems are under considerable development ...
- Published
- 2021
42. RAPIDEYE UYDU GÖRÜNTÜSÜ İLE PİKSEL TABANLI VE OBJE TABANLI SINIFLANDIRMALARIN KARŞILAŞTIRILMASI
- Author
-
Ebru Ersoy Tonyaloğlu, Engin Nurlu, Nurdan Erdogan, Kübra Kurtşan, and Betül Çavdar
- Subjects
Pixel ,Computer science ,business.industry ,Object based ,General Medicine ,Satellite image ,Object-based classification ,Classification methods ,Computer vision ,Pixel-based classification ,Artificial intelligence ,RapidEye ,LULC ,business - Abstract
The aim of this study is to evaluate the classification performances of land use/land cover (LULC) classification methods by comparing the results of pixel and object-based classification approaches on RapidEye satellite image. Pixel-based classification was carried out in ERDAS Imagine 10.4 using the Maximum Likelihood-supervised approach, whilst object-based classification was performed in e-Cognition Developer 64 using the nearest neighbour-supervised classification method. A LULC map of eight classes was created in both methods. While the accuracy for thematic LULC classes varied in both methods, the overall accuracy and kappa values of LULC maps for pixel and object-based classification methods were 58.39%-0.45 and 89.58%-0.86, respectively. Accuracy assessments and comparative results showed that object-based classification gives better results for thematic LULC classes as well as the overall accuracy of LULC maps. Even though pixel-based classification method was good at mapping many thematic classes, there were misclassifications between natural/semi-natural LULC classes. These results can be attributed to parameters set by users, such as the number of control points, etc. However, the capacity of object-based classification method to include auxiliary data (e.g. DEM, NDVI) increases the accuracy of LULC maps with high-resolution satellites.
- Published
- 2021
43. A Novel Class-Specific Object-Based Method for Urban Change Detection Using High-Resolution Remote Sensing Imagery
- Author
-
Haigang Sui, Yepei Chen, Ting Bai, Kaimin Sun, Deren Li, and Wenzhuo Li
- Subjects
Class (computer programming) ,Computer science ,Remote sensing (archaeology) ,Urban change ,Object based ,High resolution ,Computers in Earth Sciences ,Remote sensing - Abstract
A single-scale object-based change-detection classifier can distinguish only global changes in land cover, not the more granular and local changes in urban areas. To overcome this issue, a novel class-specific object-based change-detection method is proposed. This method includes three steps: class-specific scale selection, class-specific classifier selection, and land cover change detection. The first step combines multi-resolution segmentation and a random forest to select the optimal scale for each change type in land cover. The second step links multi-scale hierarchical sampling with a classifier such as random forest, support vector machine, gradient-boosting decision tree, or Adaboost; the algorithm automatically selects the optimal classifier for each change type in land cover. The final step employs the optimal classifier to detect binary changes and from-to changes for each change type in land cover. To validate the proposed method, we applied it to two high-resolution data sets in urban areas and compared the change-detection results of our proposed method with that of principal component analysis k-means, object-based change vector analysis, and support vector machine. The experimental results show that our proposed method is more accurate than the other methods. The proposed method can address the high levels of complexity found in urban areas, although it requires historical land cover maps as auxiliary data.
- Published
- 2021
44. Discovering Potential Illegal Construction Within Building Roofs from UAV Images Using Semantic Segmentation and Object-Based Change Detection
- Author
-
Yujie Sun, Shikang Tao, Min Wang, Jiru Huang, Qian Shen, and Yang Liu
- Subjects
business.industry ,Computer science ,Object based ,Segmentation ,Computer vision ,Artificial intelligence ,Computers in Earth Sciences ,business ,Change detection - Abstract
A novel potential illegal construction (PIC) detection method by bitemporal unmanned aerial vehicle (UAV ) image comparison (change detection) within building roof areas is proposed. In this method, roofs are first extracted from UAV images using a depth-channel improved UNet model. A two-step change detection scheme is then implemented for PIC detection. In the change detection stage, roofs with appearance, disappearance, and shape changes are first extracted by morphological analysis. Subroof primitives are then obtained by roof-constrained image segmentation within the remaining roof areas, and object-based iteratively reweighted multivariate alteration detection (IR-MAD ) is implemented to extract the small PICs from the subroof primitives. The proposed method organically combines deep learning and object-based image analysis, which can identify entire roof changes and locate small object changes within the roofs. Experiments show that the proposed method has better accuracy compared with the other counterparts, including the original IR-MAD, change vector analysis, and principal components analysis-K-means.
- Published
- 2021
45. Exploration of Pixel‐Based and Object‐Based Change Detection Techniques by Analyzing ALOS PALSAR and LANDSAT Data
- Author
-
Ayushman Ramola, Anurag Vidyarthi, and Amit Kumar Shakya
- Subjects
Remote sensing (archaeology) ,Computer science ,Pixel based ,Object based ,Satellite image processing ,Change detection ,Remote sensing - Published
- 2021
46. Integrating object-based image analysis and geographic information systems for waterbodies delineation on synthetic aperture radar data
- Author
-
Ioannis Kotaridis and Maria Lazaridou
- Subjects
Synthetic aperture radar ,Geographic information system ,010504 meteorology & atmospheric sciences ,business.industry ,Computer science ,Geography, Planning and Development ,Wetland management ,0211 other engineering and technologies ,Object based ,02 engineering and technology ,01 natural sciences ,Image (mathematics) ,Segmentation ,business ,Surface water ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Water Science and Technology ,Remote sensing - Abstract
Precise and regularly updated maps of surface water extent are essential for wetland management. Since it is often challenging to obtain water extent information through ground surveys due to acces...
- Published
- 2021
47. MULTISPECTRAL SHEET DIAGNOSTICS OF TECHNOLOGICAL STRESSES ON WINTER RAPES CROPS
- Author
-
Vitalii Lysenko, Aleksey Opryshko, and Natalia Pasichnyk
- Subjects
Flight altitude ,Rapeseed ,010504 meteorology & atmospheric sciences ,Automated data processing ,Multispectral image ,Object based ,Growing season ,04 agricultural and veterinary sciences ,01 natural sciences ,Agronomy ,040103 agronomy & agriculture ,High spatial resolution ,0401 agriculture, forestry, and fisheries ,General Earth and Planetary Sciences ,Environmental science ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Technological stresses are an urgent challenge for winter crops and in particular rapeseed in industrialproduction and in the mass use of agrochemicals and plant protection products. Effective resuscitationmeasures are possible only in the initial stages of the growing season and require reliable and accessibleinformation about the condition of crops. The purpose of the work is to develop an index based on the resultsof analysis of multispectral images with high spatial resolution, obtained by UAVs for the identificationof technological stresses. During field research on October 30, 2019, it was found that in the affected areas,the plants have an abnormal color of the two lower leaves, namely yellow and red. To identify affectedplants, it was proposed to use an image of the object based on the ratio of several channels simultaneously, which allow to distinguish between affected and healthy plants, soil and leaves of abnormal color. Itis proposed to use the RRL (rape red leaf) indices, which are an indicator of the technological nature ofstress, namely RRLgr, designed exclusively for the optical range and the RRLm index (green — G, red — R,border red — Re and near infrared — NIR). Such indices are convenient for monitoring the condition ofrapeseed crops and automated data processing. It was found that when monitoring rapeseed crops in thegrowing season of 6–8 leaves affected by technological stress, using Slantrange 3p height of 100 m, for the indices RRLgr and RRLm is characterized by abnormal leaf color, which was recorded in 1.5 and 2.1%of the total area of plants on the site, respectively. The use of multispectral analysis makes it possible todifferentiate the identification of technological stresses with different manifestations of impression. Ata standard flight altitude for Slantrange 3p of 100 m with the fixation of anomalous color in 1.5% of thetotal area of winter oilseed rape plants is the basis for the organization of additional ground inspection ofthe identified areas of winter oilseed rape crops.
- Published
- 2021
48. Heave Motion of a Vertical Cylinder with Heave Plates
- Author
-
Ewelina Ciba
- Subjects
heave plates ,Mechanical Engineering ,Naval architecture. Shipbuilding. Marine engineering ,Object based ,VM1-989 ,Motion (geometry) ,020101 civil engineering ,Ocean Engineering ,Fluid mechanics ,02 engineering and technology ,Vertical cylinder ,01 natural sciences ,010305 fluids & plasmas ,0201 civil engineering ,Morison equation ,damping coefficient ,Offshore wind power ,Free oscillation ,0103 physical sciences ,added mass coefficient ,Spar ,spar platforms ,Geology ,Marine engineering - Abstract
The shape of a vertical cylinder resembles the classic form of a spar platform. Spar platforms are floating platforms that are successfully used in waters of great depths and have several advantages that mean they are readily used in the oil industry. Many of these advantages are also relevant to their application for offshore wind turbines, which is currently being considered. In the hydrodynamic analysis of spar platforms, the determination of their hydrodynamic coefficients plays an important role. They can be determined based on the free decay test. The study presents a method for determining the hydrodynamic coefficients of an object based on the free decay test. The results of free oscillation calculations with the help of numerical fluid mechanics tools are presented and compared with the results of the experiment and analytical solution. The application of determined coefficients and their significance for floating platforms are discussed. The influence of change in the form of an additional damping element on the behaviour of spar structures is shown.
- Published
- 2021
49. Mapping complex coastal wetland mosaics in Gabon for informed ecosystem management: use of object‐based classification
- Author
-
Steve Schill, Allison Aldous, Tariq Stévart, Marie-Claire Paiz, Emmanuel Mambela, and George T. Raber
- Subjects
coastal wetlands ,geography ,geography.geographical_feature_category ,Central Africa ,Ecology ,business.industry ,lcsh:T ,Environmental resource management ,wetland habitat mapping ,Object based ,Central africa ,Wetland ,Image segmentation ,lcsh:Technology ,lcsh:QH540-549.5 ,Ecosystem management ,Environmental science ,wetland ecosystem management ,Gabon ,lcsh:Ecology ,Computers in Earth Sciences ,business ,image segmentation ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
Wetlands of coastal Gabon provide many ecosystems services including flood protection, water purification and wildlife habitat. Effective sustainable management of this coastal zone is hindered by a lack of accurate wetland maps. Here we describe a novel method used to map the wetland ecosystems of nearly 100 000 km2 of wetland and upland habitat mosaic in the delta of the Ogooué River using an object‐based classification of optical and radar satellite imagery based on training data collected from unmanned aerial vehicle and a post‐classification accuracy assessment using helicopter‐based video. We identified 15 land cover classes, of which nine were wetland. A stratified random sample accuracy assessment of the final classification yielded an overall accuracy of 0.80. Despite the important role that wetland habitats play for wildlife and ecosystem functioning across the region, our results indicate these wetlands cover only 22% of the project area. As expected, most of the wetland habitats are found close to major water bodies, including the Ogooué River, estuaries near the cities of Libreville and Port Gentil and coastal lagoons to the south of these cities. When considering the six Wetlands of International Importance designated under the Ramsar Convention within the project area, only 33% of mapped wetlands fall within the Ramsar site boundaries and only 10% of mapped wetlands fall within protected areas. Furthermore, within the Ramsar sites, only 31% of the land cover was classified as wetland. In order to better manage these wetland resources, more effective Ramsar boundaries would include the extensive wetland habitats found along the coast from Port Gentil south to Loango National Park. These data are now available for managers to improve wetland management within designated Ramsar sites and improving protection designations for vulnerable habitats, for example by protecting wetland connectivity and other ecosystem processes.
- Published
- 2021
50. Canopy Fuel Load Mapping of Mediterranean Pine Sites Based on Individual Tree-Crown Delineation
- Author
-
Giorgos Mallinis, Ιoannis Mitsopoulos, Panagiota Stournara, Petros Patias, and Alexandros Dimitrakopoulos
- Subjects
tree crown extraction ,GEOBIA ,object based ,canopy fuel load ,forest parameters ,Science - Abstract
This study presents an individual tree-crown-based approach for canopy fuel load estimation and mapping in two Mediterranean pine stands. Based on destructive sampling, an allometric equation was developed for the estimation of crown fuel weight considering only pine crown width, a tree characteristic that can be estimated from passive imagery. Two high resolution images were used originally for discriminating Aleppo and Calabrian pines crown regions through a geographic object based image analysis approach. Subsequently, the crown region images were segmented using a watershed segmentation algorithm and crown width was extracted. The overall accuracy of the tree crown isolation expressed through a perfect match between the reference and the delineated crowns was 34.00% for the Kassandra site and 48.11% for the Thessaloniki site, while the coefficient of determination between the ground measured and the satellite extracted crown width was 0.5. Canopy fuel load values estimated in the current study presented mean values from 1.29 ± 0.6 to 1.65 ± 0.7 kg/m2 similar to other conifers worldwide. Despite the modest accuracies attained in this first study of individual tree crown fuel load mapping, the combination of the allometric equations with satellite-based extracted crown width information, can contribute to the spatially explicit mapping of canopy fuel load in Mediterranean areas. These maps can be used among others in fire behavior prediction, in fuel reduction treatments prioritization and during active fire suppression.
- Published
- 2013
- Full Text
- View/download PDF
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