Huang Wei, Xiao Liang, Liu Hongyi, Wei Zhihui
School of Computer Science and Engineering, Nanjing University of Science & Technology, Nanjing 210094, China.
School of Science, Nanjing University of Science & Technology, Nanjing 210094, China.
Sensors (Basel). 2015 Jan 19;15(1):2041-58. doi: 10.3390/s150102041.
Due to the instrumental and imaging optics limitations, it is difficult to acquire high spatial resolution hyperspectral imagery (HSI). Super-resolution (SR) imagery aims at inferring high quality images of a given scene from degraded versions of the same scene. This paper proposes a novel hyperspectral imagery super-resolution (HSI-SR) method via dictionary learning and spatial-spectral regularization. The main contributions of this paper are twofold. First, inspired by the compressive sensing (CS) framework, for learning the high resolution dictionary, we encourage stronger sparsity on image patches and promote smaller coherence between the learned dictionary and sensing matrix. Thus, a sparsity and incoherence restricted dictionary learning method is proposed to achieve higher efficiency sparse representation. Second, a variational regularization model combing a spatial sparsity regularization term and a new local spectral similarity preserving term is proposed to integrate the spectral and spatial-contextual information of the HSI. Experimental results show that the proposed method can effectively recover spatial information and better preserve spectral information. The high spatial resolution HSI reconstructed by the proposed method outperforms reconstructed results by other well-known methods in terms of both objective measurements and visual evaluation.
由于仪器和成像光学的限制,获取高空间分辨率的高光谱图像(HSI)很困难。超分辨率(SR)图像旨在从同一场景的降质版本中推断出给定场景的高质量图像。本文提出了一种通过字典学习和空间光谱正则化的新型高光谱图像超分辨率(HSI-SR)方法。本文的主要贡献有两个方面。首先,受压缩感知(CS)框架的启发,为了学习高分辨率字典,我们鼓励图像块上更强的稀疏性,并促进学习到的字典与感知矩阵之间更小的相干性。因此,提出了一种稀疏性和非相干性受限的字典学习方法,以实现更高效率的稀疏表示。其次,提出了一种结合空间稀疏正则化项和新的局部光谱相似性保持项的变分正则化模型,以整合HSI的光谱和空间上下文信息。实验结果表明,该方法能够有效地恢复空间信息,并更好地保留光谱信息。在客观测量和视觉评估方面,用该方法重建的高空间分辨率HSI优于其他知名方法的重建结果。