计算机应用 ›› 2020, Vol. 40 ›› Issue (3): 912-916.DOI: 10.11772/j.issn.1001-9081.2019071296

• 应用前沿、交叉与综合 • 上一篇    下一篇

基于混合梯度的硬阈值追踪算法

杨立波, 蒋铁钢, 徐志强   

  1. 广东科技学院 机电工程系, 广东 东莞 523083
  • 收稿日期:2019-07-25 修回日期:2019-09-08 出版日期:2020-03-10 发布日期:2019-09-29
  • 通讯作者: 蒋铁钢
  • 作者简介:杨立波(1981-),男,黑龙江木兰人,讲师,硕士,主要研究方向:智能控制、压缩感知、仿真优化;蒋铁钢(1987-),男,湖南永州人,讲师,硕士,CCF会员,主要研究方向:图像处理、优化算法;徐志强(1983-),男,吉林扶余人,讲师,主要研究方向:智能信号处理。
  • 基金资助:
    东莞市社会科技发展项目(2019507154529)。

Hybrid gradient based hard thresholding pursuit algorithm

YANG Libo, JIANG Tiegang, XU Zhiqiang   

  1. College of Mechanical and Electrical Engineering, Guangdong University of Science and Technology, Dongguan Guangdong 523083, China
  • Received:2019-07-25 Revised:2019-09-08 Online:2020-03-10 Published:2019-09-29
  • Supported by:
    This work is partially supported by the Dongguan Social Science and Technology Development Project (2019507154529).

摘要: 针对压缩感知(CS)中迭代硬阈值类算法迭代次数多、重构时间长的问题,提出了一种基于混合梯度的硬阈值追踪(HGHTP)算法。首先,在每次迭代中计算当前迭代点处的梯度和共轭梯度,将梯度域与共轭梯度域下的支撑集混合取并集作为下一次迭代的候选支撑集,充分利用共轭梯度在支撑集选择策略中的有用信息,优化支撑集选择策略;然后,采用最小二乘法对候选支撑集进行二次筛选,快速精确地定位正确的支撑并更新稀疏系数。一维随机信号重构实验结果表明,HGHTP算法相较于同类迭代硬阈值算法,在保证重构成功率的前提下,需要的迭代次数更少。二维图像重构实验结果表明,HGHTP算法的重构精度和抗噪性能优于同类迭代阈值类算法,在保证重构精度的情况下,HGHTP算法的重构时间相比同类算法减少了32%以上。

关键词: 压缩感知, 混合梯度, 迭代硬阈值, 共轭梯度, 重构算法

Abstract: Aiming at the problem of large number of iterations and long reconstruction time of iterative hard thresholding algorithms in Compressed Sensing (CS), a Hybrid Gradient based Hard Thresholding Pursuit (HGHTP) algorithm was proposed. Firstly, the gradient and conjugate gradient at the current iteration node were calculated in each iteration, and the support sets in the gradient domain and conjugate gradient domain were mixed and the union of these two was taken as the candidate support set for the next iteration, so that the useful information of the conjugate gradient was fully utilized in the support set selection strategy, and the support set selection strategy was optimized. Secondly, the least square method was used to perform secondary screening on the candidate support sets to quickly and accurately locate the correct support and update the sparse coefficients. The experimental results of one-dimensional random signal reconstruction show that HGHTP algorithm needs fewer iterations than the similar iterative hard thresholding algorithms on the premise of guaranteeing the success rate of reconstruction. The two-dimensional image reconstruction experimental results show that the reconstruction accuracy and anti-noise performance of HGHTP algorithm are better than those of similar iterative thresholding algorithms, and under the condition of ensuring reconstruction accuracy, HGHTP algorithm has the reconstruction time reduced by more than 32% compared with similar algorithms.

Key words: Compressed Sensing (CS), hybrid gradient, iterative hard thresholding, conjugate gradient, reconstruction algorithm

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