Artifact Reduction in Radiometric Compensation of Projector-Camera Systems for Steep Reflectance Variations

In this paper, we propose a novel radiometric compensation method that applies a high-spatial-resolution camera to a projector-camera system to reduce the artifacts around the regions where the reflectance of the projection surface changes steeply. The proposed method measures the reflection in the region of a single projector pixel on a projection surface with multiple camera pixels. From the measurement, it computes multiple color-mixing matrices, each of which represents a color space conversion between each camera and the projector pixels. Using these matrices, we calculate the optimal projection color by applying the linear least squares method, so that the displayed color in the projector pixel region is as close as possible to the target appearance. Through projection experiments, we confirm that our proposed method reduces the artifacts around the regions where the reflectance changes steeply, when compared with other conventional compensation methods.