A Single-Shot 3D Measuring Method Based on Quadrature Phase-Shifting Color Composite Grating Projection
Round 1
Reviewer 1 Report
The proposed method describes a single shot color fringe projection technique combined with gray imbalance correction method. Following you can find some suggestions to improve the manuscript:
1- There are lots of single shot fringe projection techniques which were not covered in brief in introduction section. Also it is important to mention why you chose the color fringe projection method over the other methods.
2- The "sensitivity difference and color crosstalk" problem was mentioned many times but I did not find the actual meaning of this phrase till reading half of the paper. It should be described earlier.
3- In experimental and analysis section, Figure 5(d), I see some blurriness in corrected result. Blurred fringes cause some problems in measuring sharp surfaces. I think the strengths and weakness of method should be mentioned in every aspect.
4- In the experimental result you mentioned improvements without providing any numerical results. To compare different methods, you need to provide some numerical result to demonstrate how much improvement was achieved.
Author Response
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Reviewer 2 Report
The authors propose and realise a fringe-projection method for 3D shape measurements. Such measurements are of great interest because of their importance in modern manufacturing and robotics. Single-frame methods are advantageous because of higher speed and less sensitivity on mechanical disturbances. The authors describe such a novel method based on modified quadrature phase shifting and colour coding.
My questions and comments on the manuscript:
- The superiority of the authors' proposal over the traditional one (2π/3 phase shifts) is convincingly demonstrated in the experimental sections (Figs. 7 and 8). However the physical reason behind this superiority is not clear. Please try to explain the reason, at least, in qualitative terms.
- The "missing" phase step of the quadrature method is between the blue and the red channels (as Fig. 2a shows). Why? Please explain.
- Can the method be applied to coloured objects? What are the limits?
- Please specify the frame rate of the real-time experiments. Is it possible to give an estimate of the highest allowable frame rate (of course, at a given pixel resolution)? What is the limiting factor of speed?
The paper is well written in good English. Some minor errors: the sentence at line 108 should begin with a capital letter; line 164: VeiwSonic should be ViewSonic.
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The revised version covered the comments to some extent. The introduction section can be still improved. There are also lots of repetition of similar sentences in the manuscripts.
Author Response
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Author Response File: Author Response.docx
