Photometric and geometric measurements based on multi-primary image projector

Abstract

This paper presents photometric and geometric measurement methods based on a multi-primary image projector. The projector is primarily configured with a light source component and an image projection component. The light source, which can be programmed vis a computer, can reproduce any spectral curve. Spatial images are projected by a digital mirror device (DMD) chip that provides rapid control of the intensity of the light source spectra. The multi-primary images are reproduced by multiplexing the time-sequential 2D image pattern projections with various primary illuminant spectra. In this paper, we also apply the projector to photometric and geometric measurements. The first application, photometric measurement, is to one-shot-type camera spectral sensitivity measurement in which we reproduce rainbow projection for the measurement. The second application is to geometric calibration of projected color images in which we measure the geometrical relation between the projectors and camera based on visible and invisible image projection.