论文标题
可证明的阶段检索与镜下降
Provable Phase Retrieval with Mirror Descent
论文作者
论文摘要
在本文中,我们考虑了相位检索的问题,该问题包括从其$ m $线性测量的大小中恢复$ n $维的实际矢量。我们提出了一个基于明智选择的布雷格曼分歧的镜子下降(或布雷格曼梯度下降)算法,因此可以消除对非凸面相位检索目标梯度的经典全局Lipschitz的连续性要求。我们将镜下下降用于两个随机测量:\ iid标准高斯和通过编码衍射模式(CDP)获得的多个结构化照明获得的镜像。对于高斯案例,我们表明,当$ m $的测量数量足够大,而对于几乎所有初始化器的概率,算法就会恢复原始矢量,直至全球符号更改。对于这两种测量值,镜下下降均表现出局部线性收敛行为,并具有与维度无关的收敛速率。最终通过各种数值实验来说明我们的理论结果,包括对精确光学的图像重建的应用。
In this paper, we consider the problem of phase retrieval, which consists of recovering an $n$-dimensional real vector from the magnitude of its $m$ linear measurements. We propose a mirror descent (or Bregman gradient descent) algorithm based on a wisely chosen Bregman divergence, hence allowing to remove the classical global Lipschitz continuity requirement on the gradient of the non-convex phase retrieval objective to be minimized. We apply the mirror descent for two random measurements: the \iid standard Gaussian and those obtained by multiple structured illuminations through Coded Diffraction Patterns (CDP). For the Gaussian case, we show that when the number of measurements $m$ is large enough, then with high probability, for almost all initializers, the algorithm recovers the original vector up to a global sign change. For both measurements, the mirror descent exhibits a local linear convergence behaviour with a dimension-independent convergence rate. Our theoretical results are finally illustrated with various numerical experiments, including an application to the reconstruction of images in precision optics.