Universal Journal of Electrical and Electronic Engineering Vol. 4(3), pp. 73 - 79
DOI: 10.13189/ujeee.2016.040301
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Average Surface Roughness Measurement Using Photometric Stereo Method

Thammarat Somthong ^*, Qing-Ping Yang
College of Engineering, Design and Physical Sciences, Brunel University London, UK

ABSTRACT

This paper presents a technique for measuring surface roughness (Ra), using photometric stereo method. The method utilizes three or more images of the measured surface from the same view point, taken sequentially under different illumination conditions. The scenes captured by the camera were reconstructed by the least square method to obtain surface normal from surface topography. Three-dimensional surface textural patterns were recovered from those surfaces normal. The system was validated with three standard surface roughness specimens. The Ra calculated from the recovered surface was compared with the nominal value of the standard surface roughness. The best coefficient of the slant angles can also be determined through the linear regression. The experimental results indicate that the technique can be applied to well recover standard surface roughness.

KEYWORDS
Surface Texture, Photometric Stereo, Measurement, Imaging Techniques

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Thammarat Somthong , Qing-Ping Yang , "Average Surface Roughness Measurement Using Photometric Stereo Method," Universal Journal of Electrical and Electronic Engineering, Vol. 4, No. 3, pp. 73 - 79, 2016. DOI: 10.13189/ujeee.2016.040301.

(b). APA Format:
Thammarat Somthong , Qing-Ping Yang (2016). Average Surface Roughness Measurement Using Photometric Stereo Method. Universal Journal of Electrical and Electronic Engineering, 4(3), 73 - 79. DOI: 10.13189/ujeee.2016.040301.