High Spatial Resolution Remote Sensing Image Research Articles

Large patch convolutional neural networks for the scene classification of high spatial resolution imagery

The increase of the spatial resolution of remote-sensing sensors helps to capture the abundant details related to the semantics of surface objects. However, it is difficult for the popular object-oriented classification approaches to acquire higher level semantics from the high spatial resolution remote-sensing (HSR-RS) images, which is often referred to as the “semantic gap.” Instead of designing sophisticated operators, convolutional neural networks (CNNs), a typical deep learning method, can automatically discover intrinsic feature descriptors from a large number of input images to bridge the semantic gap. Due to the small data volume of the available HSR-RS scene datasets, which is far away from that of the natural scene datasets, there have been few reports of CNN approaches for HSR-RS image scene classifications. We propose a practical CNN architecture for HSR-RS scene classification, named the large patch convolutional neural network (LPCNN). The large patch sampling is used to generate hundreds of possible scene patches for the feature learning, and a global average pooling layer is used to replace the fully connected network as the classifier, which can greatly reduce the total parameters. The experiments confirm that the proposed LPCNN can learn effective local features to form an effective representation for different land-use scenes, and can achieve a performance that is comparable to the state-of-the-art on public HSR-RS scene datasets.

Scene classification based on multifeature probabilistic latent semantic analysis for high spatial resolution remote sensing images

Scene classification can mine high-level semantic information scene categories from low-level visual features for high spatial resolution remote sensing images (HSRIs). A multifeature probabilistic latent semantic analysis (MPLSA) algorithm is proposed to perform the task of scene classification for HSRIs. Distinct from the traditional probabilistic latent semantic analysis (PLSA) with a single feature, to utilize the spatial information of the HSRIs, in MPLSA, multiple features, including spectral and texture features, and the scale-invariant feature transform feature, are combined with PLSA. The visual words are characterized by the multifeature descriptor, and an image set is represented by a discriminative word-image matrix. During the training phase, the MPLSA model mines the visual words’ latent semantics. For unknown images, the MPLSA model analyzes their corresponding latent semantic distributions by combining the words’ latent semantics obtained from the training step. The spectral angle mapper classifier is utilized to label the scene class, based on the image’s latent semantic distribution. The experimental results demonstrate that the proposed MPLSA method can achieve better scene classification accuracy than the traditional single-feature PLSA method.

An Approximate Spectral Clustering Ensemble for High Spatial Resolution Remote-Sensing Images

Unsupervised clustering of high spatial resolution remote-sensing images plays a significant role in detailed land-cover identification, especially for agricultural and environmental monitoring. A recently promising method is approximate spectral clustering (SC) which enables spectral partitioning for large datasets to extract clusters with distinct characteristics without a parametric model. It also facilitates the use of various information types via advanced similarity criteria. However, it requires an empirical selection of a similarity criterion optimal for the corresponding application. To address this challenge, we propose an approximate SC ensemble (ASCE2) which fuses partitionings obtained by different similarity representations. Contrary to existing spectral ensembles for remote-sensing applications, the proposed ASCE2 employs neural gas quantization instead of random sampling, advanced similarity criteria instead of traditional distance-based Gaussian kernel with different decay parameters, and a two-level ensemble. We evaluate the proposed ASCE2 with three measures (accuracy, adjusted Rand index, and normalized mutual information) using five remote-sensing images, two of which are commonly available. We apply the ASCE2 in two applications for agricultural monitoring: 1) land-cover identification to determine orchard fields using a WorldView-2 image (0.5-m spatial resolution) and 2) finding lands in good agricultural condition using multitemporal RapidEye images (5-m spatial resolution). Experimental results indicate a significant betterment of the resulting partitionings obtained by the proposed ensemble, with respect to the evaluation measures in these applications.

Hyperspectral data spectrum and texture band selection based on the subspace-rough set method

In order to improve the utilization rate of spectroscopic data and texture information, this study proposes a method for optimal selection of spectrum and texture features based on automatic subspace division and rough set theory. This method takes advantage of rough set reduct ideology in order to realize the reduction of different types of ground object spectral features on the basis of the conventional subspace division method. In using this method, the primary spectral band based on spectral information can be determined. Then, the grey-level co-occurrence matrix method can be used to calculate the texture information of the primary spectral band and determine the reduction and optimization in order to obtain the final band based on the spectrum and texture information. Verification of this method is made by using CASI data of Heihe Region, China, and AVIRIS data of the Indiana Region, USA, and also using Support Vector Machine (SVM) classification of the original spectral, primary spectral, and final bands. The results indicate the following. (1) The method for optimal selection of the critical spectral band and texture band, based on the rough set theory, can efficiently improve the classification accuracy of high-spatial resolution remote-sensing images. However, the effects for the low-spatial resolution images are minimal. (2) For high-spatial-resolution remote-sensing images, such as roads, trenches, buildings, and other types of object with obvious textural features, the addition of image texture information can increase the degree of distinction of these different types and thereby improve the classification accuracy. However, the addition of the textural information for some objects with similar texture features will cause misclassification and reduce the classification accuracy for these types of images. (3) This method can realize the optimal selection of spectrum and texture bands of a hyperspectral image and has a certain universality. Also, the texture information will be richer and this method will be more practical through increasing the spatial resolution of images.

Object-Based Multi-Feature Classification of High Spatial Resolution Remote Sensing Image

This paper analysis the characteristics of High Spatial Resolution Remote Sensing Image (HSRRSI), consider the drawback of pixel-wise Classification, an Object-based method was taken to classify the image. The paper firstly preprocess and coarsely segment the image, secondly optimize the segmented results for deeply processing, then extracting the image feature from the original image and segmented results, finally classify the image and assess the results.

Surface Feature Extraction on the Basis of Object-oriented Remote Sensing Classification Methods in Manas River Basin

Remote-sensing (RS) images were extracted by using object-oriented remote sensing classification methods. This study combines RS and Geographic Information System to conduct multilevel segmentation and classify of the remote sensing image of Manas watershed. The e-Cognition system was selected to define the knowledge base following the classification system. The results show that the overall nicety of grading can reach 97.37% and that the Kappa coefficient is 0.9706. These results show that land use can be described and extracted by using high spatial resolution remote-sensing images.

A novel method for assessing the segmentation quality of high-spatial resolution remote-sensing images

Image segmentation quality significantly affects subsequent image classification accuracy. It is necessary to develop effective methods for assessing image segmentation quality. In this paper, we present a novel method for assessing the segmentation quality of high-spatial resolution remote-sensing images by measuring both area and position discrepancies between the delineated image region (DIR) and the actual image region (AIR) of a scene object. In comparison with the most frequently used area coincidence-based methods, our method can assess the segmentation quality more objectively in that it takes into consideration all image objects intersecting with the AIR of a scene object. Moreover, the proposed method is more convenient to use than the existing boundary coincidence-based methods in that the calculation of the distance between the boundary of the image object and that of the corresponding AIR of the scene object is not required. Another benefit of this method over the two types of method above is that the assessment procedure of the segmentation quality can be conducted with less human intervention. The obtained optimal segmentation result can ensure maximal delineation of the extent of scene objects and can be beneficial to subsequent classification operations. The experimental results have shown the effectiveness of this new method for both segmentation quality assessment and optimal segmentation parameter selection.

Multi-agent Remote Sensing Image Segmentation Algorithm

Due to fractal network evolution algorithm (FNEA) in the treatment of the high spatial resolution remote sensing image (HSRI) using a parallel global control strategies which limited when the objects in each cycle by traversal of and not good use the continuity of homogenous area on the space and lead to problems such as bad image segmentation, therefore puts forward the remote sensing image segmentation algorithm based on multi-agent. The algorithm in the merger guidelines, combining the image spectral and shape information, and by using region merging process of multi-agent parallel control integral, its global merger control strategy can ensure algorithm has the advantages of parallel computing and fully considering the regional homogeneity, and continuity. Finally simulation experiment was performed with FNEA algorithms, experimental results show that the proposed algorithm is better than FNEA algorithm in dividing the overall effect, has a good stability

Circular array targets detection from remote sensing images based on saliency detection

To extract circular array targets from high-spatial resolution optical satellite images, we propose an efficient two-step detection framework. In the first stage, we propose a multiscale histogram contrast (MHC) saliency evaluation model to detect salient objects. This saliency model is able to highlight all salient areas with well-defined boundaries and effectively suppress the obvious background textures. Moreover, the generated saliency map can be used to find the locations of potential targets most likely causing visual attention, which greatly decreases the computation cost in later processes. In the second stage, we extract task-related targets from these salient objects by removing the irrelevant salient areas according to the special properties of the targets. In this paper, we present a circular array targets-detection method based on the saliency map produced by the proposed saliency detector. First we extract the circular objects from the saliency map using simple shape features, which are then clustered through a graph-based approach to locate the target areas. To evaluate the performance of our saliency model and targets extraction scheme, we carried out many experiments on large-field, high-spatial resolution remote-sensing images and achieved promising results both in efficiency and precision.

Technology Study in Division of Forest Resources Based on the High-spatial Resolution Remote Sensing Images

The main method of current forest resources sub-compartment division is adopted drawing division boundary according to the condition of opposite hillside in the field,which existence of human subjectivity and lacks of scientific objectivity in this approach.This paper brings forward the strategy of object-oriented multi-scale segmentation,which takes different segmentation scales according to the feature information of diferent scales.Based on this,the multi-scale segmentation network is established and the layered extraction of the feature information is realized.And then in sub-compartment division of forest resources,experimental results show that the method can greatly improve the accuracy of the sub-compartment division in image-based automatic interpretation.