- Volume 3 Issue 5
DOI QR Code
Generating a True Color Image with Data from Scanning White-Light Interferometry by Using a Fourier Transform
- Kim, Jin-Yong (School of Mechanical and Aerospace Engineering, Seoul National University) ;
- Kim, Seungjae (Sindoh Co., Ltd.) ;
- Kim, Min-Gyu (School of Mechanical and Aerospace Engineering, Seoul National University) ;
- Pahk, Heui Jae (School of Mechanical and Aerospace Engineering, Seoul National University)
- Received : 2019.04.30
- Accepted : 2019.06.05
- Published : 2019.10.25
In this paper we propose a method to generate a true color image in scanning white-light interferometry (SWLI). Previously, a true color image was obtained by using a color camera, or an RGB multichannel light source. Here we focused on acquiring a true color image without any hardware changes in basic SWLI, in which a monochrome camera is utilized. A Fourier transform method was used to obtain the spectral intensity distributions of the light reflected from the sample. RGB filtering was applied to the intensity distributions, to determine RGB values from the spectral intensity. Through color corrections, a true color image was generated from the RGB values. The image generated by the proposed method was verified on the basis of the RGB distance and peak signal-to-noise ratio analysis for its effectiveness.
Scanning white-light interferometry;Metrology;True color;Fourier transforms
Supported by : Seoul National University
- Z. Malacara and M. Servín, Interferogram Analysis For Optical Testing (CRC Press, Boca Raton, USA, 2005), Chapter 3.
- L. Deck and P. de Groot, "High-speed noncontact profiler based on scanning white-light interferometry," Appl. Opt. 33, 7334-7338 (1994). https://doi.org/10.1364/AO.33.007334
- P. de Groot, "Principles of interference microscopy for the measurement of surface topography," Adv. Opt. Photonics 7, 1-65 (2015). https://doi.org/10.1364/AOP.7.000001
- P. de Groot, "Coherence Scanning Interferometry," in Optical Measurement of Surface Topography, R. Leach. ed. (Springer Verlag, Berlin, Germany, 2011), Chapter 9, pp 187-208.
- S. W. Kim and G. H. Kim, "Thickness-profile measurement of transparent thin-film layers by white-light scanning interferometry," Appl. Opt. 38, 5968-5973 (1999). https://doi.org/10.1364/AO.38.005968
- N. Kim, S. W. Lee, Y. I, and H. J. Pahk, "Accurate roughness measurement using a method for evaluation and interpolation of the validity of height data from a scanning white-light interferometer," Curr. Opt. Photon. 1, 604-612 (2017).
- J. Schmit and F. Munteanu, "Full-color images produced by white-light interferometry," U.S. Patent 9282304B1 (2016).
- J. L. Beverage, X. C. de Lega, and M. F. Fay, "Interferometric microscope with true color imaging," Proc. SPIE 9203, 92030S (2014).
- J. Schmit, S. H. Bui, D. Chen, and M. J. Novak, "Side illumination in interferometry," U.S. Patent 9746315B1 (2017).
- P. de Groot and X. C. de Lega, "Signal modeling for lowcoherence height-scanning interference microscopy," Appl. Opt. 43, 4821-4830 (2004). https://doi.org/10.1364/AO.43.004821
- J.-T. Dong and R.-S. Lu, "Sensitivity analysis of thin-film thickness measurement by vertical scanning white-light interferometry," Appl. Opt. 51, 5668-5675 (2012). https://doi.org/10.1364/AO.51.005668
- G. Choi, Y. Lee, S. W. Lee, Y. Cho, and H. J. Pahk, "Simple method for volumetric thickness measurement using a color camera," Appl. Opt. 57, 7550-7558 (2018). https://doi.org/10.1364/AO.57.007550
- D. R. Hearn, Fourier transform interferometry. No. TR-1053. Massachusetts Institute of Technology: Lincoln Laboratory, 1999.
- S. Bianco, A. Bruna, F. Naccari, and R. Schettinid, "Color correction pipeline optimization for digital cameras," J. Electron. Imaging 22, 023014 (2013). https://doi.org/10.1117/1.JEI.22.2.023014
- S. T. Welstead, Fractal and wavelet image compression techniques (SPIE Optical Engineering Press, Bellingham, WA, USA, 1999), pp. 155-156.
- M. Barni, Document and Image compression (CRC Press, Boca Raton, USA, 2006), pp. 168-169.