Preliminary measurements of oil paint on paper using a mid-infrared hyperspectral imaging system with a bolometer camera and image interferometer.

Abstract

The research focuses on developing a cutting-edge far-infrared HSI (Hyperspectral imaging) system using a bolometer camera, a unique instrument worldwide. This system has been utilized to conduct test measurements on various samples. While previous measurements with this system successfully captured the transmission of samples and the characteristics of inks and adhesives on aluminum plates, the current study introduces improvements in the instrument and measurement method. These advancements have allowed for measuring oil paints on paper, marking a significant achievement. Specifically, 16 different oil paints (four black, four white, four blue, and four red) were subjected to measurement. A compact far-infrared HSI instrument comprising an imaging interferometer and a bolometer camera was employed. The obtained spectra were compared with those obtained using another FTIR spectrometer. To ensure consistent measurements, the sample was rotated during the process, guaranteeing uniform spectra across the entire field of view of the instrument. The success or failure of each measurement was also determined by analyzing the amplitude of the interference signal in each pixel. The results revealed varying degrees of success among the measured oil paints, with paints exhibiting higher reflectance yielding better results, while paints with lower reflectance posed significant challenges. Furthermore, the success of the measurements was influenced by the orientation of the sample's undulating surface. These results show that oil paints can be measured with the world's first far-infrared HIS system with a bolometer camera.