In this article, we propose an effective method for gonio-spectral imaging of paper and cloth samples under oblique illumination conditions. High resolution gonio-spectral images are synthesized from a basic spectral image and gonio-monochrome images. The method is based on gonio-spectral image fusion composed of two components, conventional spatial fusion and geometrical fusion. The proposed geometrical fusion synthesizes images at different geometries and is introduced by modeling the optical reflection properties with a dichromatic reflection model. The validity of this method is confirmed by gonio-spectral measurements of paper samples, and experiments are performed on Japanese washi paper and European cloth.