“Contrast”is an generic denomination for“difference”.Measures of contrast are a powerful tool in image processing and analysis,e.g.,in denoising,edge detection,segmentation,classification,parameter estimation,chan...“Contrast”is an generic denomination for“difference”.Measures of contrast are a powerful tool in image processing and analysis,e.g.,in denoising,edge detection,segmentation,classification,parameter estimation,change detection,and feature selection.We present a survey on techniques that aim at measuring the contrast between(i)samples of SAR imagery,and(ii)samples and models,with emphasis on those that employ the statistical properties of the data.展开更多
Region-based classification of PolSAR data can be effectively performed by seeking for the assignment that minimizes a distance between prototypes and segments.Silva et al.[“Classification of segments in PolSAR image...Region-based classification of PolSAR data can be effectively performed by seeking for the assignment that minimizes a distance between prototypes and segments.Silva et al.[“Classification of segments in PolSAR imagery by minimum stochastic distances between wishart distributions.”IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 6(3):1263–1273]used stochastic distances between complex multivariate Wishart models which,differently from other measures,are computationally tractable.In this work we assess the robustness of such approach with respect to errors in the training stage,and propose an extension that alleviates such problems.We introduce robustness in the process by incorporating a combination of radial basis kernel functions and stochastic distances with Support Vector Machines(SVM).We consider several stochastic distances between Wishart:Bhatacharyya,Kullback-Leibler,Chi-Square,Rényi,and Hellinger.We perform two case studies with PolSAR images,both simulated and from actual sensors,and different classification scenarios to compare the performance of Minimum Distance and SVM classification frameworks.With this,we model the situation of imperfect training samples.We show that SVM with the proposed kernel functions achieves better performance with respect to Minimum Distance,at the expense of more computational resources and the need of parameter tuning.Code and data are provided for reproducibility.展开更多
基金partially founded by CNPq(Brazilian National Council for Scientific and Technological Development)Fapeal(the State Science Foundation-Alagoas State,Brazil)
文摘“Contrast”is an generic denomination for“difference”.Measures of contrast are a powerful tool in image processing and analysis,e.g.,in denoising,edge detection,segmentation,classification,parameter estimation,change detection,and feature selection.We present a survey on techniques that aim at measuring the contrast between(i)samples of SAR imagery,and(ii)samples and models,with emphasis on those that employ the statistical properties of the data.
基金Fundacao de Amparoa Pesquisa do Estado de Sao Paulo(FAPESP)(Grant 2014/14830-8)UNESP/PROPe(Grant 2016/1389)+1 种基金Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq)Fundacao de Amparoa Pesquisa do Estado de Alagoas(Fapeal)for funding this research.
文摘Region-based classification of PolSAR data can be effectively performed by seeking for the assignment that minimizes a distance between prototypes and segments.Silva et al.[“Classification of segments in PolSAR imagery by minimum stochastic distances between wishart distributions.”IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 6(3):1263–1273]used stochastic distances between complex multivariate Wishart models which,differently from other measures,are computationally tractable.In this work we assess the robustness of such approach with respect to errors in the training stage,and propose an extension that alleviates such problems.We introduce robustness in the process by incorporating a combination of radial basis kernel functions and stochastic distances with Support Vector Machines(SVM).We consider several stochastic distances between Wishart:Bhatacharyya,Kullback-Leibler,Chi-Square,Rényi,and Hellinger.We perform two case studies with PolSAR images,both simulated and from actual sensors,and different classification scenarios to compare the performance of Minimum Distance and SVM classification frameworks.With this,we model the situation of imperfect training samples.We show that SVM with the proposed kernel functions achieves better performance with respect to Minimum Distance,at the expense of more computational resources and the need of parameter tuning.Code and data are provided for reproducibility.
