Object-based Markov Random Field Research Articles

Power Line Detection for Aerial Images Using Object-Based Markov Random Field With Discrete Multineighborhood System

Power Line Detection for Aerial Images Using Object-Based Markov Random Field With Discrete Multineighborhood System

Semantic Segmentation for Remote Sensing Image Using the Multigranularity Object-Based Markov Random Field With Blinking Coefficient

Semantic Segmentation for Remote Sensing Image Using the Multigranularity Object-Based Markov Random Field With Blinking Coefficient

A Self-Learning-Update CNN Model for Semantic Segmentation of Remote Sensing Images

Convolutional neural network (CNN) has been widely used in semantic segmentation for remote sensing images, and it has achieved great success. Due to the diversity of the spatial distribution of terrestrial objects in remote sensing images, it is difficult to effectively learn general geographical laws and apply them to a specific image. To introduce geographical knowledge into the CNN model more effectively, a self-learning-update CNN model (SLU-CNN) is proposed in this letter. It learns the representation of specific spatial dependence among different objects according to the CNN result, and then incorporates it with the CNN result to make semantic inference available. The proposed method mainly involves two modules. First, geographical objects generated from the CNN result are used as inference units. Second, the spatial dependence between inference units is learned to build a specific adaptive geographical relationship. And then, it is embedded as an adaptive penalty term into an object-based Markov random field model to achieve the collaboration between the CNN result and the semantic inference. Our method provides a general data-knowledge dual-driven framework for the deep neural network. Experiments of the GID and Sentinel-2 datasets validate the effectiveness of the proposed method by comparing it with different state-of-the-art CNN methods.

A Method Combining Line Detection and Semantic Segmentation for Power Line Extraction from Unmanned Aerial Vehicle Images

Power line extraction is the basic task of power line inspection with unmanned aerial vehicle (UAV) images. However, due to the complex backgrounds and limited characteristics, power line extraction from images is a difficult problem. In this paper, we construct a power line data set using UAV images and classify the data according to the image clutter (IC). A method combining line detection and semantic segmentation is used. This method is divided into three steps: First, a multi-scale LSD is used to determine power line candidate regions. Then, based on the object-based Markov random field (OMRF), a weighted region adjacency graph (WRAG) is constructed using the distance and angle information of line segments to capture the complex interaction between objects, which is introduced into the Gibbs joint distribution of the label field. Meanwhile, the Gaussian mixture model is utilized to form the likelihood function by taking the spectral and texture features. Finally, a Kalman filter (KF) and the least-squares method are used to realize power line pixel tracking and fitting. Experiments are carried out on test images in the data set. Compared with common power line extraction methods, the proposed algorithm shows better performance on images with different IC. This study can provide help and guidance for power line inspection.

Semantic Segmentation for Remote Sensing Images Using Pyramid Object-Based Markov Random Field With Dual-Track Information Transmission

Semantic Segmentation for Remote Sensing Images Using Pyramid Object-Based Markov Random Field With Dual-Track Information Transmission

An Object-Based Markov Random Field with Partition-Global Alternately Updated for Semantic Segmentation of High Spatial Resolution Remote Sensing Image

The Markov random field (MRF) method is widely used in remote sensing image semantic segmentation because of its excellent spatial (relationship description) ability. However, there are some targets that are relatively small and sparsely distributed in the entire image, which makes it easy to misclassify these pixels into different classes. To solve this problem, this paper proposes an object-based Markov random field method with partition-global alternately updated (OMRF-PGAU). First, four partition images are constructed based on the original image, they overlap with each other and can be reconstructed into the original image; the number of categories and region granularity for these partition images are set. Then, the MRF model is built on the partition images and the original image, their segmentations are alternately updated. The update path adopts a circular path, and the correlation assumption is adopted to establish the connection between the label fields of partition images and the original image. Finally, the relationship between each label field is constantly updated, and the final segmentation result is output after the segmentation has converged. Experiments on texture images and different remote sensing image datasets show that the proposed OMRF-PGAU algorithm has a better segmentation performance than other selected state-of-the-art MRF-based methods.

SEMANTIC SEGMENTATION OF REMOTE SENSING IMAGERY USING OBJECT-BASED MARKOV RANDOM FIELD BASED ON HIERARCHICAL SEGMENTATION TREE WITH AUXILIARY LABELS

Abstract. In the remote sensing imagery, spectral and texture features are always complex due to different landscapes, which leads to misclassifications in the results of semantic segmentation. The object-based Markov random field provides an effective solution to this problem. However, the state-of-the-art object-based Markov random field still needs to be improved. In this paper, an object-based Markov Random Field model based on hierarchical segmentation tree with auxiliary labels is proposed. A remote sensing imagery is first segmented and the object-based hierarchical segmentation tree is built based on initial segmentation objects and merging criteria. And then, the object-based Markov random field with auxiliary label fields is established on the hierarchical tree structure. A probabilistic inference is applied to solve this model by iteratively updating label field and auxiliary label fields. In the experiment, this paper utilized a Worldview-3 image to evaluate the performance, and the results show the validity and the accuracy of the presented semantic segmentation approach.

PolSAR Image Classification Based on Object-Based Markov Random Field With Polarimetric Auxiliary Label Field

Recently, an object-based Markov random field (OMRF) with auxiliary fields (OMRF-A) was developed for the processing of optical remote sensing images and it provided satisfactory results. However, it cannot be directly applied to polarimetric synthetic aperture radar (PolSAR) images with high heterogeneity. In addition, polarimetric information which plays a dominant role in PolSAR image interpretation cannot be effectively incorporated by the OMRF-A model. In order to solve this problem, an OMRF with polarimetric auxiliary fields (OMRF-PA) is developed in this letter for the classification of PolSAR images. A polarimetric index is developed to evaluate the information loss during iterations of label fields and auxiliary label fields. Then, an improved conditional probability distribution which incorporates the polarimetric index is proposed to account for the interactions between label fields and auxiliary label fields. Experiments on PolSAR data sets acquired by ESAR and EMISAR systems demonstrate that the proposed OMRF-PA model can generate a higher classification accuracy compared to the original OMRF-A method.

An Object-Based Markov Random Field Model with Anisotropic Penalty for Semantic Segmentation of High Spatial Resolution Remote Sensing Imagery

The Markov random field model (MRF) has attracted a lot of attention in the field of remote sensing semantic segmentation. But, most MRF-based methods fail to capture the various interactions between different land classes by using the isotropic potential function. In order to solve such a problem, this paper proposed a new generalized probability inference with an anisotropic penalty for the object-based MRF model (OMRF-AP) that can distinguish the differences in the interactions between any two land classes. Specifically, an anisotropic penalty matrix was first developed to describe the relationships between different classes. Then, an expected value of the penalty information (EVPI) was developed in this inference criterion to integrate the anisotropic class-interaction information and the posteriori distribution information of the OMRF model. Finally, by iteratively updating the EVPI terms of different classes, segmentation results could be achieved when the iteration converged. Experiments of texture images and different remote sensing images demonstrated that our method could show a better performance than other state-of-the-art MRF-based methods, and a post-processing scheme of the OMRF-AP model was also discussed in the experiments.

Segmentation for remote-sensing imagery using the object-based Gaussian-Markov random field model with region coefficients

ABSTRACTThe Markov random field (MRF) model is a widely used method for remote-sensing image segmentation, especially the object-based MRF (OMRF) method has attracted great attention in recent years. However, the OMRF method usually fails to capture the correlation between regional features by just considering the mixed-Gaussian model. In order to solve this problem and improve the segmentation accuracy, this article proposes a new method, object-based Gaussian-Markov random field model with region coefficients (OGMRF-RC), for remote-sensing image segmentation. First, to describe the complicated interactions among regional features, the OGMRF-RC method employs the region size and edge information as region coefficients to build the object-based linear regression equation (OLRE) for each region. Second, the classic Gaussian-Markov model is extended to region level for modelling the errors in OLREs. Finally, the segmentation is achieved through a principled probabilistic inference designed for the OGMRF-RC method. Experimental results over synthetic texture images and remote-sensing images from different datasets show that the proposed OGMRF-RC method can achieve more accurate segmentation than other state-of-the-art MRF-based methods and the method using convolutional neural networks.

Power Line Extraction From Aerial Images Using Object-Based Markov Random Field With Anisotropic Weighted Penalty

The extraction of power line plays a key role in power line inspection by Unmanned Aerial Vehicles (UAVs). While it is challenging to extract power lines in aerial images because of the weak targets and the complex background. In this paper, a novel power line extraction method is proposed. First of all, we create a line segment candidate pool which contains power line segments and large amount of other line segments. Secondly, we construct the irregular graph model with these line segments as nodes. Then a novel object-based Markov random field with anisotropic weighted penalty (OMRF-AWP) method is proposed. It defines a new neighborhood system based on the irregular graph model and builds a new potential function by considering the region angle information. With the OMRF-AWP method, we can distinguish between the power line segments and other line segments. Finally, an envelope-based piecewise fitting (EPF) method is proposed to fit the power lines. Experimental results show that the proposed method has good performance in multiple scenes with complex background.

Semantic Segmentation of Remote Sensing Imagery Using an Object-Based Markov Random Field Model With Auxiliary Label Fields

The Markov random field (MRF) model has attracted great attention in the field of image segmentation. However, most MRF-based methods fail to resolve segmentation misclassification problems for high spatial resolution remote sensing images due to insufficiently using the hierarchical semantic information. In order to solve such a problem, this paper proposes an object-based MRF model with auxiliary label fields that can capture more macro and detailed information and apply it to the semantic segmentation of high spatial resolution remote sensing images. Specifically, apart from the label field, two auxiliary label fields are first introduced into the proposed model for interpreting remote sensing images from different perspectives, which are implemented by setting a different number of auxiliary classes. Then, the multilevel logistic model is used to describe the interactions within each label field, and a conditional probability distribution is developed to model the interactions between label fields. A net context structure is established among them to model the interactions of classes within and between label fields. A principled probabilistic inference is suggested to solve the proposed model by iteratively renewing the label field and auxiliary label fields, in which different information of auxiliary label fields can be integrated into the label field during iterations. Experiments on different remote sensing images demonstrate that our model produces more accurate segmentation than the state-of-the-art MRF-based methods. If some prior information is added, the proposed model can produce accurate results even in complex areas.

Object-based change detection method using refined Markov random field

In order to fully consider the local spatial constraints between neighboring objects in object-based change detection (OBCD), an OBCD approach is presented by introducing a refined Markov random field (MRF). First, two periods of images are stacked and segmented to produce image objects. Second, object spectral and textual histogram features are extracted and G-statistic is implemented to measure the distance among different histogram distributions. Meanwhile, object heterogeneity is calculated by combining spectral and textual histogram distance using adaptive weight. Third, an expectation-maximization algorithm is applied for determining the change category of each object and the initial change map is then generated. Finally, a refined change map is produced by employing the proposed refined object-based MRF method. Three experiments were conducted and compared with some state-of-the-art unsupervised OBCD methods to evaluate the effectiveness of the proposed method. Experimental results demonstrate that the proposed method obtains the highest accuracy among the methods used in this paper, which confirms its validness and effectiveness in OBCD.

Multilayer semantic segmentation of remote-sensing imagery using a hybrid object-based Markov random field model

ABSTRACTHigh spatial resolution (HR) remote-sensing image usually contains hierarchical semantic information. Many supervised methods have been developed to interpret this information through data training. In this article, without data training, a hybrid object-based Markov random field (HOMRF) model is proposed for multilayer semantic segmentation of remote-sensing images. In this method, label fields of different semantic layers are defined on the same region adjacency graph (RAG) of a given image, and a hybrid framework is suggested to capture and utilize the interactions within and between semantic layers by label fields. Namely a new transition probability matrix is introduced into the energy functions of label fields for describing the semantic context between layers, and the multilevel logistic model is employed to describe the interactions within the same layer. A principled probabilistic inference is developed to determine the optimal solution of the proposed method by iteratively updating each label field until convergence. The computational complexity of the proposed model is , where is the number of classes in all of the layers, is the number of sites in the probability graph of the MRF model, and is the number of iterations. Experimental results from various remote-sensing images demonstrate that the proposed method can produce higher segmentation accuracy than state-of-the-art MRF-based methods.

Semantic Segmentation of Remote Sensing Imagery Using Object-Based Markov Random Field Model With Regional Penalties

This paper proposes a novel object-based Markov random field model (OMRF) for semantic segmentation of remote sensing images. First, the method employs the region size and edge information to build a weighted region adjacency graph (WRAG) for capturing the complicated interactions among objects. Thereafter, aimed at modeling object interactions in the OMRF, the size and edge information are further introduced into the Gibbs joint distribution of the random field as regional penalties. Finally, the semantic segmentation is achieved through a principled probabilistic inference of the OMRF with regional penalties. The proposed method is compared with other MRF-based methods and some state-of-the-art methods. Experiments are conducted on a series of synthetic and real-world images. Segmentation results demonstrate that our method provides better performance (an accuracy improvement about 3%). Moreover, we further discuss the application of the proposed method for classification.

Urban area detection from high-spatial resolution remote sensing imagery using Markov random field-based region growing

Dynamically changing urban areas require periodic automatic monitoring, but urban areas include various objects and different objects show diverse appearances. This makes it difficult to effectively detect urban areas. A region-growing method using the Markov random field (MRF) model is proposed for urban detection. It consists of three modules. First, it provides an automatic urban seed objects extraction approach by designing three features with respect to urban characteristics. Second, the method uses an object-based MRF to model the spatial relationship between urban seed objects and surrounding objects. Third, a MRF-based region-growing criterion is proposed to detect urban areas based on seed points and spatial constraints. The strength of the proposed method lies in two aspects. One is that automatic selection of seed points is presented instead of manual selection. The other one is that the region-growing technique, instead of probabilistic inference, is used to solve the MRF optimization problem. Experiments on aerial images and SPOT5 images demonstrate that our method provides a better performance compared with the region-growing method, the classical and object-based MRF methods, or some other state-of-art methods.