Robust Watermarking Scheme for Vector Geographic Data Based on the Ratio Invariance of DWT–CSVD Coefficients

Round 1

Reviewer 1 Report

The authors have proposed a robust watermarking scheme for vector geographic data based on the ratio invariance of DWT–CSVD coefficients. The paper is well organized and the method is properly explained. The authors have also presented an analysis of the qualitative and quantitative performance of the proposed method. I have the following observation on their contribution.

1.The symbol T and H in Equation (2) are not explained adequately, what is the difference between them?

 

2.It is recommended to introduce and cite the literature on the definition of the matrix of Haar Wavelet transform to support the use of equation (5).

 

3.The IDWT mentioned in step 6 of section 2.4.1 should be expressed in the form of a formula.

 

4.It is recommended to explain the Douglas-Peucker algorithm mentioned in step 1 of Section 2.4.2, or cite the corresponding literature.

 

5.Tables 3 and 6 provide conflicting results with respect to scaling; Please reevaluate them or add further tests with justification.

 

6. Please read and cite (if applicable) more papers that are related to this article and helpful to the revision.

- A GIS-Based Mathematical Approach for Generating 3D Terrain Model from High-Resolution UAV Imageries

- 3D Cadaster Creation from Generalized Blueprint Based on Semantic Boundary Point Extraction

 

 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

There are some comments for authors:

1.While not affecting the conclusion of ratio invariance, Equations 16 and 17 do not appear to be the correct way to write the singular value components. Please check if there is an error in the Equations.

2. In Figure 3, the value at each position inside the ratio K is represented by ‘x’. It is easy to cause the reader to think that every bit of the value of K is the same value, which is obviously unreasonable, so please characterize it with a different symbol or marker.

3. Table 4 and Table 6 both have ‘×’, but they represent different meanings, please replace the symbols to distinguish them.

4.In the watermark embedding flow chart (Figure 4), the arrow indication from singular values SL and singular values SH to K and S' is not clear.

5.Why some NC values are less than 0.6, but some NC values are identified as ‘×’ in Table 4. Since none of them can be verified as copyright, what is the difference between them?

6.Table 3 shows that the proposed watermarking algorithm is able to extract identifiable watermark image at smaller degree of scaling, while in that section of ‘3.4 comparative analysis’ shows that the proposed algorithm is not robust to scaling attacks. Thus, the experimental result is contrary to the conclusion, please clarify or add experiments.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

in section 1, introduction:
what is "meaningless copyright information"? please rephrase

I disagree with the way things are cited, for example:
"Zope-Chaudhari et al [22,23[ achieved copyright protection .. DWT coefficients." -- certainly, but they were not the first, and there are many other works
similarly, [27] is used as reference for Arnold transform; it's not the original work introducing Arnold transform, but rather some application
similarly, [28] is used as reference for NC, it's just some (random) paper using it

in section 2, methods:
"where L_2 is the approximate component of H and H_2 is the detail component of H." -- usually L_2 denotes the approximation of the approximation (2-level decomposition), I'm confused how the subbands are derived

in section 2.2:
what motivates the choice of eq. (20)?

in section 2.3:
the embedding seems very ad-hoc, has it been used elsewhere? literature?
is it optimal? why was it chosen this way? replacing digits in decimal numbers seems inconvenient to implement

in section 3.2:
I don't think embedding strength factors 0.5 vs 1e-6 of other watermarking schemes can be compared directly in a meaningful way
maybe to a measure of the total distortion introduced by watermarking can be compared?

one aspect of watermarking vector data is imposing a "distortion constraint" such that line segment to not begin to intersect after watermarking (this can be quite disastrous for representing country borders, etc.) -- any observations regarding this aspect?


typo abstract:
"singular values of the both" ??

typo introduction:
"has become an important technical" -- technology?
"protection vector geographical data" -- protection of

typo section 3.3:
"robustness of in schemes in [22,29]" -- of in

Ref [10] Cox, G ... Proceedings of the Proceedings of the ???

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

what is XNOR ... exclusive XOR?! (Eq. 28)

Author Response

Dear reviewer,

 

Thank you again for taking time to review our manuscript.

We studied your comment and revised our draft.

We also went through our manuscript and made a few corrections on the texts.

Hope that our revised draft will meet with your approval.

 

Best wishes,

Chengyi Qu, Xu Xi, Jinglong Du, Tong Wu

 

Point 1: what is XNOR ... exclusive XOR?! (Eq. 28)

 

Response 1: [author response] Thank you for your question. Here is our misrepresentation. XNOR is a combination XOR gate followed by an inverter. In XNOR, the output is 1 if the inputs are the same, and 0 if the inputs are different.

[author action]:  XNOR () denotes exclusive XOR logical operation. XNOR(•) denotes the operator of exclusive NOR. (Please see the second paragraph of section 2.4.2)