A Continuous Millimeter-Wave Imaging Scanner for Art Conservation Science
Figure 2
(a) Photograph of the sample (paint layers covering a graphite sketch), (90 mm × 55 mm); (b) transmission CW image at 240 GHz; (c) transmission CW image after application of a FFT bandpass filter (Image J software) to remove background interference pattern; (d) transmission pulsed THz image at 240 GHz. In (b) to (d), black level indicates a decrease of THz signal.