Abstract
One of the main problems faced by the photometric stereo method is that several measurements are required, as this method needs illumination from light sources from different directions. A solution to this problem is the color photometric stereo method, which conducts one-shot measurements by simultaneously illuminating lights of different wavelengths. However, the classic color photometric stereo method only allows measurements of white objects, while a surface-normal estimation of a multicolored object using this method is theoretically impossible. Therefore, it is necessary to add some constraints to estimate the surface normal of a multicolored object using the framework of the color photometric stereo method. In this study, a median filter is employed as the constraint condition of albedo, and the surface normal of the occluding boundary is employed as the constraint condition of the surface normal. By employing a median filter as the constraint condition, the smooth distribution of the albedo and normal is calculated while the sharp features at the boundary of different albedos and normals are preserved. The surface normal at the occluding boundary is propagated into the inner part of the object region, and forms the abstract shape of the object. Such a surface normal gives a great clue to be used as an initial guess to the surface normal. To demonstrate the effectiveness of this study, a measurement device that can realize the multispectral photometric stereo method with seven colors is employed instead of the classic color photometric stereo method with three colors.
Highlights
To reproduce a detailed surface shape, normal information is necessary
This paper proposes a technique that employs some constraints so that it can be applied to colored objects, which is impossible for conventional color photometric stereo
This paper demonstrates that multi-spectral cameras and multi-spectral light sources are effective for the color photometric stereo method
Summary
To reproduce a detailed surface shape, normal information is necessary To obtain this information, the photometric stereo method was proposed, which estimates the normal by transitioning the brightness levels of several pictures by changing the direction of the light source. The photometric stereo method was proposed, which estimates the normal by transitioning the brightness levels of several pictures by changing the direction of the light source As it requires multiple photoshoots, the photometric stereo method is not suitable for modeling a moving object. To measure the shape of a moving object, the color photometric stereo method, which employs several colored light sources, was developed. This method involves placing light sources of red, green, and blue colors in three different directions, which simultaneously illuminate the target object. Unlike the common color photometric stereo method, we use seven narrow-band lights with different peak wavelengths while observing the target object with a seven-band multispectral camera
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
