PONE-D-19-25883

Image Quality Metric System for Color Filter Array (CFA) Evaluation

PLOS ONE

Dear Dr. Bae,

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Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Partly

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: N/A

Reviewer #2: N/A

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Reviewer #1: No

Reviewer #2: Yes

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PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors propose a method to evaluate the mosaic of CFA camera. The topic is very interesting and the proposal quite convincing, though the evaluation of the protocol and the conclusions are limited.

Hereafter are some comments:

You need to position your work vs. this article:

A no-reference metric for demosaicing artifacts that fits psycho-visual experiments

F Gasparini, F Marini, R Schettini, M Guarnera - EURASIP Journal on Advances in Signal Processing, 2012

Not clear how the mosaics, in particular complex/pseudo-random mosaics or general mosaics (SFA) will impact the relevant of the method. In particular in the case of a color transform from N bands to colour.

Random color filter arrays are better than regular ones

P Amba, J Dias, D Alleysson - Color and Imaging Conference, 2016

and

Multispectral filter arrays: Recent advances and practical implementation

PJ Lapray, X Wang, JB Thomas, P Gouton - Sensors, 2014

Neither the role of the algorithm definition:

Xin Li, Bahadir Gunturk, Lei Zhang, "Image demosaicing: a systematic survey," Proc. SPIE 6822, Visual Communications and Image Processing 2008, 68221J (28 January 2008);

and

Demosaicing of periodic and random color filter arrays by linear anisotropic diffusion

JB Thomas, I Farup - Color and Imaging Conference, 2018

I think this needs to be discussed, because the simulation and evaluation of your framework is limited to regular patterns and very basic demosaicing. It is very difficult to study mosaic alone in this case and get strong conclusion. In fact in particular Moire might be also limited by the use of better algorithm combined to each mosaic, which limit the conclusions.

That does not impact the definition of the evaluation method though.

It is not very well described what are the characteristics of the spectral data used. This needs to be described because it may impair the simulation.

Beside I encourage to revise the references: there were many online accessed documents. Some might be find in academic articles properly cited rather than a link, this must be fixed.

As well, you may provide more specific acknowledgement to what the cited person have actually done to desserve those.

English and text could be improved.

Reviewer #2: The article presents that: currently the most frequently used method of demosaicing in terms of cost and time of computation is bilinear interpolation. On what basis did it say so? There is, for example, the method of the nearest neighbour interpolation which is even faster and requires much less resources.

It would be worthwhile to see how the results obtained for different CFA systems behave for different demosaicing methods.

Consideration should be given to the statement: The pipeline typically consists of demosaicking, noise reduction, white balance, CFA interpolation, color conversion, and gamma correction for rendering the sensor data.

Is the formulation correct and is this the correct order of operations?

The proposed quality assessment system for different CFA has been reduced to a selection of several metrics used to assess the quality of a digital image where a reference image is required. The article proposes visualization in the form of polar coordinates. For different CFA systems we obtain a different distribution, however, it is the subjective observer who must assess which of the measurements is more important for him.

The authors should look at another measure of image quality assessment closely correlated with HVS. Examples of such metrics are: DSCSI, MDSI, HPSI etc…

Lee, Dohyoung, and Konstantinos N. Plataniotis. "Towards a full-reference quality assessment for color images using directional statistics." IEEE Transactions on image processing 24.11 (2015): 3950-3965.

Nafchi, Hossein Ziaei, et al. "Mean deviation similarity index: Efficient and reliable full-reference image quality evaluator." IEEE Access 4 (2016): 5579-5590.

Reisenhofer, Rafael, et al. "A Haar wavelet-based perceptual similarity index for image quality assessment." Signal Processing: Image Communication 61 (2018): 33-43.

It is also worthwhile to examine the articles:

Frackiewicz, Mariusz, and Henryk Palus. "Toward a perceptual image quality assessment of color quantized images." Tenth International Conference on Machine Vision (ICMV 2017). Vol. 10696. International Society for Optics and Photonics, 2018.

Frackiewicz, Mariusz, and Henryk Palus. "New image quality metric used for the assessment of color quantization algorithms." Ninth International Conference on Machine Vision (ICMV 2016). Vol. 10341. International Society for Optics and Photonics, 2017.

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Reviewer #1: No

Reviewer #2: No

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PONE-D-19-25883R1

Image Quality Metric System for Color Filter Array Evaluation

PLOS ONE

Dear Dr. Bae,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

We would appreciate receiving your revised manuscript by Apr 25 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Hocine Cherifi

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: No

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The work is improved, however there are still quite strong limitations:

2 major conceptual concerns:

1-It is not only the demosacing that seems to be evaluated, but the whole imaging pipeline, as shown in Fig 2. At least

2-Generally the writing part should be reworked and be more structured, accurate and concise.

Less major comments:

1-Do you really need to introduce all the formula for the IQMs?

2-The results should be supported by a psychophysical experiment OR why you do not do it should be very clearly stated (in this case you seem to enforce that the recent IQM correlate with perception, but then you use many metrics that do not correlate very well with perception).

3-An exercise of quantitative summary/analysis of the results would be welcome.

4-I invite you to revisit my first rounds of comments.

Minor comments:

1-Figs are not readible because too small.

2-PUPPY image and other images are not referenced and it is not sure if the simulation was in spectral or in colour only.

In general I would like this work to be published, but would appreciate it to be more compact. Beside I am not sure that Plos One is the right support for this technical development (up to the editors to take this decision though)

Reviewer #2: Are there statistically significant differences between the CFA systems tested for quality indices?

In Table 1 there are identical values for HPSI, MDSI and others for different CFA systems, maybe you need to use a different way of presenting the results?

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Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

Image Quality Metric System for Color Filter Array Evaluation

PONE-D-19-25883R2

Dear Dr. Bae,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

With kind regards,

Hocine Cherifi

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Thanks for answering my comments.

The article is OK for publication. The experiment is described clearly, which was one of my major concern.

Reviewer #2: The author took into account previous comments and advice. I don't have any additional suggestions for work.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

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Reviewer #1: No

Reviewer #2: No