期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2021
卷号：118
期号：47
DOI：10.1073/pnas.2116067118
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Kagias and Stampanoni (
1) claim that there are a few passages that are inaccurate in our recent publication (
2). We dispute this claim. We agree that the directional derivates can be calculated by having access to two orthogonal components; in fact, this is already described and included in our publication (
2).
The multiple directional differential phase images (DDPI) can be directly measured with the method proposed (
2), and the amplitude
A
1
differential phase and the phase term
ϕ
A
can be derived with fast Fourier transform (FFT) analysis. The DDPI at any angle
θ can be expressed as follows (equation 4 in ref.
2):
[1
