Superpixel Segmentation Based on Spatially Constrained Subspace Clustering
Huazhong University of Science and Technology（华中科技大学）；City University of Hong Kong（香港城市大学）；Southeast University（东南大学）；Beijing Jiaotong University（北京交通大学）
Superpixel segmentation aims at dividing the input image into some representative regions containing pixels with similar and consistent intrinsic properties, without any prior knowledge about the shape and size of each superpixel. In this paper, to alleviate the limitation of superpixel segmentation applied in practical industrial tasks that detailed boundaries are difficult to be kept, we regard each representative region with independent semantic information as a subspace, and correspondingly formulate superpixel segmentation as a subspace clustering problem to preserve more detailed content boundaries. We show that a simple integration of superpixel segmentation with the conventional subspace clustering does not effectively work due to the spatial correlation of the pixels within a superpixel, which may lead to boundary confusion and segmentation error when the correlation is ignored. Consequently, we devise a spatial regularization and propose a novel convex locality-constrained subspace clustering model that is able to constrain the spatial adjacent pixels with similar attributes to be clustered into a superpixel and generate the content-aware superpixels with more detailed boundaries. Finally, the proposed model is solved by an efficient alternating direction method of multipliers (ADMM) solver. Experiments on different standard datasets demonstrate that the proposed method achieves superior performance both quantitatively and qualitatively compared with some state-of-the-art methods.
National University of Defense Technology（国防科技大学）；University of Trento（特伦托大学）
This paper presents a tensor alignment (TA) based domain adaptation method for hyperspectral image (HSI) classification. To be specific, HSIs in both domains are first segmented into superpixels and tensors of both domains are constructed to include neighboring samples from single superpixel. Then we consider the subspace invariance between two domains as projection matrices and original tensors are projected as core tensors with lower dimensions into the invariant tensor subspace by applying Tucker decomposition. To preserve geometric information in original tensors, we employ a manifold regu…
Joint Superpixel and Self-Representation Learning for Scalable Hyperspectral Image Clustering
Department of Telecommunications and Information Processing（电信与信息处理系）；Ghent University（根特大学）；Royal Institute for Cultural Heritage (KIK-IRPA)（皇家文化遗产研究院）；School of Computer Science（计算机科学学院）；China University of Geosciences（中国地质大学）
This paper investigates the problem of image segmentation using superpixels. We propose two approaches to enhance the discriminative ability of the superpixel's covariance descriptors. In the first one, we employ the Log-Euclidean distance as the metric on the covariance manifolds, and then use the RBF kernel to measure the similarities between covariance descriptors. The second method is focused on extracting the subspace structure of the set of covariance descriptors by extending a low rank representation algorithm on to the covariance manifolds. Experiments are carried out with the Berkly S…
Remote Sensing Technology Institute（遥感技术研究所）；Helmholtz Association（亥姆霍兹联合会）；German Research Foundation (DFG)（德国研究基金会（DFG））；European Research Council (ERC)（欧洲研究委员会（ERC））；German Federal Ministry of Education and Research (BMBF)（德国联邦教育和研究部（BMBF））；AXA Research Fund（安盛研究基金）
Conventional nonlinear subspace learning techniques (e.g., manifold learning) usually introduce some drawbacks in explainability (explicit mapping) and cost-effectiveness (linearization), generalization capability (out-of-sample), and representability (spatial-spectral discrimination). To overcome these shortcomings, a novel linearized subspace analysis technique with spatial-spectral manifold alignment is developed for a semi-supervised hyperspectral dimensionality reduction (HDR), called joint and progressive subspace analysis (JPSA). The JPSA learns a high-level, semantically meaningful, jo…
Nankai International Advanced Research Institute（南开大学国际高等研究院）；Peng Cheng Laboratory（鹏城实验室）；College of Computer Science, Nankai University（南开大学计算机学院）；University of Science and Technology Beijing（北京科技大学）；University of Macau（澳门大学）
Nanjing University（南京大学）；Huazhong University of Science and Technology（华中科技大学）
This paper proposes an affinity fusion graph framework to effectively connect different graphs with highly discriminating power and nonlinearity for natural image segmentation. The proposed framework combines adjacency-graphs and kernel spectral clustering based graphs (KSC-graphs) according to a new definition named affinity nodes of multi-scale superpixels. These affinity nodes are selected based on a better affiliation of superpixels, namely subspace-preserving representation which is generated by sparse subspace clustering based on subspace pursuit. Then a KSC-graph is built via a novel ke…
Sun Yat-sen University（中山大学）；Advanced Digital Sciences Center（先进数字科学中心）；Anhui University（安徽大学）
Driven by recent vision and graphics applications such as image segmentation and object recognition, computing pixel-accurate saliency values to uniformly highlight foreground objects becomes increasingly important. In this paper, we propose a unified framework called PISA, which stands for Pixelwise Image Saliency Aggregating various bottom-up cues and priors. It generates spatially coherent yet detail-preserving, pixel-accurate and fine-grained saliency, and overcomes the limitations of previous methods which use homogeneous superpixel-based and color only treatment. PISA aggregates multiple…
School of Engineering and Technology, Central Queensland University（中央昆士兰大学工程与技术学院）
Scene parsing aims to recognize the object category of every pixel in scene images, and it plays a central role in image content understanding and computer vision applications. However, accurate scene parsing from unconstrained real-world data is still a challenging task. In this paper, we present the non-parametric Spatially Constrained Local Prior (SCLP) for scene parsing on realistic data. For a given query image, the non-parametric SCLP is learnt by first retrieving a subset of most similar training images to the query image and then collecting prior information about object co-occurrence …
Hubei University of Technology（湖北工业大学）；Huazhong University of Science and Technology（华中科技大学）；Nanjing University（南京大学）
Affinity graph-based segmentation methods have become a major trend in computer vision. The performance of these methods relies on the constructed affinity graph, with particular emphasis on the neighborhood topology and pairwise affinities among superpixels. Due to the advantages of assimilating different graphs, a multi-scale fusion graph has a better performance than a single graph with single-scale. However, these methods ignore the noise from images which influences the accuracy of pairwise similarities. Multi-scale combinatorial grouping and graph fusion also generate a higher computatio…
The Institute of Cancer Research（英国癌症研究院）；Royal Free London（伦敦皇家自由医院）
The spectacular response observed in clinical trials of immunotherapy in patients with previously uncurable Melanoma, a highly aggressive form of skin cancer, calls for a better understanding of the cancer-immune interface. Computational pathology provides a unique opportunity to spatially dissect such interface on digitised pathological slides. Accurate cellular classification is a key to ensure meaningful results, but is often challenging even with state-of-art machine learning and deep learning methods. We propose a hierarchical framework, which mirrors the way pathologists perceive tumour …
German Aerospace Center (DLR)（德国航空航天中心）；Technical University of Munich (TUM)（慕尼黑工业大学）；Beijing Institute of Technology（北京理工大学）；Helmholtz-Zentrum Dresden-Rossendorf（亥姆霍兹德累斯顿罗森多夫研究中心）；Univ. Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；INRIA（法国国家信息与自动化研究所）；CNRS（法国国家科学研究中心）；Grenoble INP（格勒诺布尔国立高等物理、数学与信息学院）
Up to the present, an enormous number of advanced techniques have been developed to enhance and extract the spatially semantic information in hyperspectral image processing and analysis. However, locally semantic change, such as scene composition, relative position between objects, spectral variability caused by illumination, atmospheric effects, and material mixture, has been less frequently investigated in modeling spatial information. As a consequence, identifying the same materials from spatially different scenes or positions can be difficult. In this paper, we propose a solution to addres…
Hyperspectral Image Classification via Efficient Global Spectral Supertoken Clustering
Beijing Institute of Technology, Beijing 100081, China（北京理工大学）；Beijing Institute of Technology Chongqing Innovation Center, Chongqing 401135, China（北京理工大学重庆创新中心）；Key Laboratory of Photoelectronic Imaging Technology and System, Ministry of Education of China, Beijing 100081, China（光电成像技术与系统重点实验室）
Scalable Context-Preserving Model-Aware Deep Clustering for Hyperspectral Images
Ghent University（根特大学）；Royal Institute for Cultural Heritage (KIK-IRPA)（皇家文化遗产研究院）；China University of Geosciences（中国地质大学）；Vrije Universiteit Brussel（布鲁塞尔自由大学）
