First of all, we thank you for your great effort reviewing our paper ...
First of all, we thank you for your great effort reviewing our paper ... First of all, we thank you for your great effort reviewing our paper ...
color channel is captured for a white light. Even though Zhang ZH’s paper did not notice thisproblem, but it was there unfortunately.The point by point phase estimation is needed since the Bayer pattern alternates between red,blue and green, so there may be a significant intensity variation in a 2x2 grid which may affectan estimate based on neighboring points. If a 3‐CCD camera is used, there will be less intensityvariation (a white board will be an even color in red, green, blue), so this wouldn't be as much aproblem. The point by point phase estimation can be augmented with local variations to detectlarge gradients or discontinuities which affect phase wrapped systems.This is true to this sense, but the geometry measured would be problematic besides its morecost, as already addressed.In other words, most of the disadvantages of the techniques described in the paper are due to aBayer pattern being used instead of a 3‐CCD camera. The use of a Bayer pattern is usually just ainexpensive way to replace a 3‐CCD camera, since the colors are spatially multiplexed. Althoughthe ability to use a Bayer pattern camera is advantageous in terms of cost , it in some wayconfuses the description and advantages of the main technique to solve the color problems byadding an additional (unncesssary) layer of color demultiplexing (which is well known) and theassociated problems with the Bayer pattern described above. I would suggest discussing thetechniques to solve the color problems without the Bayer pattern, then add the Bayer patternand discuss further advantages and disadvantages.The whole point of this paper yet: Low cost (no increase), simultaneous geometry and colortexture measurement, and possibly for real‐time 3D shape measurement. Of course, 3‐CCDcameras will work too although it might bring other problems.• The paper does not seem to emphasize the principle and advantages of the main techniqueused to overcome the color bleeding and object color problems; They are mentioned in onesentence in the principle section and in another sentence in the setup section. It would help thereader to describe how variations in color bleeding and object color do not affect the phase andcolor estimates, rather than just stating that with B/W fringes it isn't a problem. Similarly, thereis not much emphasis given to the limitations of this technique, such as when the fringes aren'tcolor balanced or the effects of chromatic aberration.Already done, in the introduction part, refer above.• Despite of the claims of being novel, very little new is added in terms of technique, analysis,or setup from previous works by the author. The use of color phase shifted fringes for singlepixel phase extraction and phase unwrapping have been previously published. The equationsand calibration techniques are from previous works. The Bayer filter and color deinterlacing(from the averaged image) are well known.
I am pretty sure that our paper provided an elegant solution for this problem instead of utilizingmultiple fringe images, or 3‐CCD camera, or color coupling matrix, etc. We have received greatcomments from the SPIE conference this year at San Diego. We believe many audiences werevery much impressed by this elegant solution, even though we may not be able to convince youthat our paper is important.The main techniques of this paper used to remove the color bleeding and object color effectsand to capture the color texture are the use of B/W fringes and averaging the fringes toproduce a fringeless image. These ideas both mentioned in one of the author's (Zhang S)previous works "High‐resolution, real‐time three‐dimensional shape measurement" [3]. Itstates, "Color tolerance: Unlike those real time systems based on color‐coded structured lightmethods, this system uses B/W fringe images. Therefore the object color does not affect themeasurement accuracy." " ...averaging the three fringe patterns washes out the fringes ...",although they use the camera's exposure time to do the averaging, rather than do it in software.Also, "It should also be noted that we can also obtain a B/W image for the texture mapping byaveraging the three phase‐shifted fringes". One of the future works this paper suggested was tosimply replace the B/W camera with a color camera.The fact that a small change in the setup has produced the desired ability to capturesimultaneous 3D geometry and color texture is not lost on this reviewer. However, with this inmind, the results should be either presented as a Letter (which I don't believe gives the endresult the proper exposure it deserves), or more in‐depth analysis should be performed.I do recommend that this paper be published, but the paper needs to be revised with somestructural changes and additional analysis to present the work in its best light.In addition, we made the following changes in this paper:Abstract: on page 2, line 1, we addedand rapidlyAbstract: on page 2, line 3, we addedUsing a single color camera either reduces the measurement speed or drastically sacrifices themeasurement qualityAbstract: on page 2, line 11, we added:Since only three fringe images are required, this technique is suitable for real time 3‐D shapemeasurement.Section 1: page 3, line 3, we added:With recent advancements of real‐time 3‐D shape measurement technologies, theSection 1: page 3, line 3, we added:With recent advancements of real‐time 3‐D shape measurement technologies, theSection 5: page 15, 6 lines from bottom, we added:
- Page 3 and 4: For instance, a recent paper [1] Zh
- Page 5 and 6: The phase shifting algorithm should
- Page 7 and 8: calibrated under the same lighting
- Page 9: eal‐time 3D absolute coordinate m
color channel is captured <strong>for</strong> a white light. Even though Zhang ZH’s <strong>paper</strong> did not notice thisproblem, but it was there un<strong>for</strong>tunately.The point by point phase estimation is needed since the Bayer pattern alternates bet<strong>we</strong>en red,blue and green, so there may be a significant intensity variation in a 2x2 grid which may affectan estimate based on neighboring points. If a 3‐CCD camera is used, there will be less intensityvariation (a white board will be an even color in red, green, blue), so this wouldn't be as much aproblem. The point by point phase estimation can be augmented with local variations to detectlarge gradients or discontinuities which affect phase wrapped systems.This is true to this sense, but the geometry measured would be problematic besides its morecost, as already addressed.In other words, most <strong>of</strong> the disadvantages <strong>of</strong> the techniques described in the <strong>paper</strong> are due to aBayer pattern being used instead <strong>of</strong> a 3‐CCD camera. The use <strong>of</strong> a Bayer pattern is usu<strong>all</strong>y just ainexpensive way to replace a 3‐CCD camera, since the colors are spati<strong>all</strong>y multiplexed. Althoughthe ability to use a Bayer pattern camera is advantageous in terms <strong>of</strong> cost , it in some wayconfuses the description and advantages <strong>of</strong> the main technique to solve the color problems byadding an additional (unncesssary) layer <strong>of</strong> color demultiplexing (which is <strong>we</strong>ll known) and theassociated problems with the Bayer pattern described above. I would suggest discussing thetechniques to solve the color problems without the Bayer pattern, then add the Bayer patternand discuss further advantages and disadvantages.The whole point <strong>of</strong> this <strong>paper</strong> yet: Low cost (no increase), simultaneous geometry and colortexture measurement, and possibly <strong>for</strong> real‐time 3D shape measurement. Of c<strong>our</strong>se, 3‐CCDcameras will work too although it might bring other problems.• The <strong>paper</strong> does not seem to emphasize the principle and advantages <strong>of</strong> the main techniqueused to overcome the color bleeding and object color problems; They are mentioned in onesentence in the principle section and in another sentence in the setup section. It would help thereader to describe how variations in color bleeding and object color do not affect the phase andcolor estimates, rather than just stating that with B/W fringes it isn't a problem. Similarly, thereis not much emphasis given to the limitations <strong>of</strong> this technique, such as when the fringes aren'tcolor balanced or the effects <strong>of</strong> chromatic aberration.Already done, in the introduction part, refer above.• Despite <strong>of</strong> the claims <strong>of</strong> being novel, very little new is added in terms <strong>of</strong> technique, analysis,or setup from previous works by the author. The use <strong>of</strong> color phase shifted fringes <strong>for</strong> singlepixel phase extraction and phase unwrapping have been previously published. The equationsand calibration techniques are from previous works. The Bayer filter and color deinterlacing(from the averaged image) are <strong>we</strong>ll known.
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