Hierarchical Feature Enhancement Algorithm for Multispectral Infrared Images of Dark and Weak Targets

Round 1

Reviewer 1 Report

The authors proposed a multispectral infrared zoom optical system design and a single-frame hierarchical guided filtering image enhancement algorithm, which addressed the technical problems of low contrast, blurred edges, and weak signal strength of single-spectrum infrared imaging of faint targets. The data is abundant, and the result is promising. However, many format and language issues make it hard to read, also the way of figure presentation. I strongly recommend the authors reread their manuscript and replot the figures.

1.     Please double check all the figures to unify font size, font tyle, figure quality, and layout, e.g., Fig.5 some figures are just screenshots, some texts are hard to read, even there are Chinese characters. Fig. 7 also screenshots. Fig.3 what is the unit of the x-y labels?

2.     The abbreviation should be introduced first, e.g., the ones in abstract.

3.     For the equations, the usage of symbols are confusing, e.g., Line 142 what is A? in 124 it is input image, what is epsilon? Physical parameters should be in italic form. Eq. 19. The “time” mark in Line 218.

4.     In Lines 201 and 208, how did the authors determine the values of beta 1, 2, and 3?

5.     What does this mean “This section may be divided by subheadings. It should provide a concise and precise description of the experimental results, their interpretation, as well as the experimental conclusions that can be drawn.” in Section 3?

6.     “This is achieved by using materials with a lower coefficient of color difference between bands or by controlling the incidence of light on the surface of the element, among other methods, in order to eliminate color differences in the multispectral range.” What does the author mean of “color difference” here? What is the physical meaning and relation to choose the material? Is there a more correlated term?

7.     Line 321 “From the above table, it can be seen that the system is expected to have good imaging quality within the predetermined tolerances. The existing level of machining and set-up is basically sufficient to meet the design requirements of the system.” What is the criteria to evaluate the performance and draw the conclusion? The analysis is missing.

8.     Line 413 “The histogram comparison analysis shows that (f1) the image brightness information is uniform, and (f2) the comparison analysis with other three-dimensional gray scale statistics shows that the highest value of contrast is 70 for the CLAHE algorithm, 120 for the GWGIF algorithm, 90 for the VWGIF algorithm, and 180 for the proposed algorithm, with a contrast ratio enhancement of about 33%. (f3) Comparison analysis with other 2D intensity statistical graphs, where the highest value of intensity of the CLAHE algorithm is 70, the highest value of intensity of the GWGIF algorithm is 140, the highest value of intensity of the VWGIF algorithm is 100, and the highest value of intensity of the proposed algorithm in this paper is 200, with an intensity enhancement of about 30%. The proposed algorithm enhances the target edges, the contrast between the target and the background, and the detail of the target.” should be much more concise.

9.     Table 6, please mark your results and the best results with specific colors.

Please refine the language and remove the typos.

Author Response

Thank you very much for your guidance and revision suggestions, please refer to the attached article for detailed revision responses! Good luck with your work and good health!

Author Response File: Author Response.pdf

Reviewer 2 Report

In this paper, the authors introduced a multispectral infrared zoom optical system design and a single-frame hierarchical guided filtering image enhancement algorithm are proposed to address the technical problems of low contrast, blurred edges, and weak signal strength of single-spectrum infrared imaging of faint 11 targets, which are easily drowned out by noise. The multi-spectral infrared zoom optical system, based on the theory of complex achromatic and mechanical positive group compensation, can simultaneously acquire multi-spectral image information for faint target. The idea behind this is interesting. However, I still have quite a number of concerns in this manuscript. There are times where there are not enough data to support the conclusions of the author. Please see some of the major concerns below.

 

1.The information for the improved bootstrap filtering algorithm flow (figure 2) is not enough. The authors should give much more information about this. So the readers can get its reproducibility.  For example, what is the stability and hardware cost and time of realizing this algorithm, meaning what is the tradeoff?

 

2.  The authors should give much more information about the novelty of this paper, especially the effect of using the improved bootstrap filtering algorithm, which applications can be used this device?

3. The algorithm tolerance analysis, which can offer a good guide for the robust requirement, and the key parameters, need to be added in the results section.

4. More references need to be included in the introduction part to understand the applications of using filtering image or signals enhancement for image algorithms.

a.     Improving Raman spectra of pure silicon using super-resolved method

- Journal of Optics, 2019

b.     Improved diagnostic process of multiple sclerosis using automated detection and selection process in magnetic resonance imaging

- Applied Sciences, 2017

5.  Much more discussion about the results should be given in this paper, especially the author needs to provide enough physicals mechanism analysis about the results.

 

6. Major note is that figures 3,4,7 are not clear at all.  Figure 3 no units in the x and y axis wavelength (nm or um ?-> not clear at all), figure 5 cannot be seen, the font is below 10 font size, so nobody can see it, visibility must to be improve. Also, figure 7 where are the units in the hist figure? it should be y-axis pixels numbers vs intensity range level.

Author Response

Thank you very much for your guidance and revision suggestions, please refer to the attached article for detailed revision responses! Good luck with your work and good health!

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have done intensive revision to the draft and it is much better now, I am happy to suggest it for publication.

Reviewer 2 Report

The new version is much better so it can be published.