On Ghost Imaging Studies for Information Optical Imaging

Round 1

Reviewer 1 Report

Please see the attachment.

Comments for author File: Comments.pdf

Author Response

We are truly thankful for the comments provided by the reviewer. In
the revised manuscript, we have done our best to incorporate the suggestions. Our point-to-point response to comments is in the attached files.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors provide a pretty instructive review about studies on ghost imaging under the view of information optical imaging. By comparing between traditional imaging configuration and ghost imaging, as well as the information theory of communication, the possibility of ghost imaging is thoroghly discussed. Since the information acquisition mode and the encoding method of ghost imaging are not strictly fixed, while they are largely fixed for traditional imaging, ghost imaging is promising to overcome those limitions that traditional imaging systems have. Based on different descriptions of imaging, including joint moments, intensity correlation, mathematical formulation, theory of ghost imaging is briefly given. Then related studies on ghost imaging for information optical imaging are rearranged, especially on mapping higher-dimensional information into lower-dimentsional domain, resolution analysis, encoding, task-orientd design, and X-ray diffraction GI. For improving, I suggest the authors consider the following issues.

1. When mapping higher-dimensional informtion into lower-dimensional domain, we might achieve higher efficiency of information acquisition, but what is the price? Will it cause mixture of information and thus more requirements on infromation reconstruction?

2. For analysis on resolution, I think the authors only pay attention to spatial resolution. What about resolution in other dimensions?

3.  There exist studies on adaptive or feedback ghost imaging. I guess those can also be classified as a kind of optimization the encoding mode. 

4.  Those discussion on X-ray diffraction GI appears not so tightly related to other parts.

Upon the above comments, I can recommend this manuscipt to be published with optional revisions. 

Author Response

We are truly thankful for the comments provided by the reviewer. In
the revised manuscript, we have done our best to incorporate the suggestions. Our point-to-point response to comments is in the attached files.

Author Response File: Author Response.pdf

Reviewer 3 Report

An interesting review paper which begins by analyzing optical imaging systems from the point of view of information theory. Conventional imaging systems where signals map directly from the object to the image plane are shown to have significant redundancy, particularly when the end requirement is a non-imaging taks e.g. object recognition. A mathematical approach is used to show how ghost imaging can overcome the limitations of conventional imaging in terms of redundancy by extracting information from high order correlation of light fields. A range of GI techniques and activities are explained and described in detail with full mathematical descriptions of the methods used. Techniques to reduce information redundancy and optimise for task-oriented applications are discussed. The paper generally well written the concepts explained with an excellent level of detail, but the english grammar is difficult to read in places and would benefit from significant revision. In particular, there are many long sentences which would be much easier to comprehend if split up. Improvements in conciseness and clarity would be beneficial.

Specific comments:

Generally: The author should correct the use of the indefinite and definite articles "a" and "the" which are misued or missing in many places throughout the paper. While the author's meaning can be gleaned, the english grammar should be revised, to simplify and clarify meaning. In particular, very long sentences should be avoided.
Page: 2 - paragraph 1. This is a very long sentence. Split into several to improve readability.
Page: 2 - line 65. X-rays should be plural.
Page: 2 - line 69. Replace "of" with "for".
Page: 3 - line 76. Very long sentence thats needs splitting and simplifying.
Page: 3 - line 86. Replace "would" by "will".
Page: 4 - line 99. "Concerned" is an incorrrect word choice. Do you mean "considered"?
Page: 7 - line 147. Change "illumininating" to "illumination".
Page: 9 - line 183. Change "flexible" to "flexibly".
Page: 9 - line 196. Change "combining" to "combined".
Page: 9 - line 194. "The effect of this scheme .. was demonstrated": A reference is required here.
Page: 9 - line 212. Revise grammar. e.g. USING fundamental information-theoretic studies IT is possible
Page: 10 - line 232-3. Improve english grammar.
Page: 11 - line 280. Sentence is too long. Split into 2 or more.
Page: 13 - line 330. Change to "resulting in".
Page: 13 - line 368. Change "on the constrast" to "in contrast".

Author Response

We are truly thankful for the comments provided by the reviewer. In
the revised manuscript, we have done our best to incorporate the suggestions. For easy tracking, we have also color-coded our changes in the revised manuscript.

Our point-to-point response to comments is in the attached files. 

Author Response File: Author Response.pdf