If multiple objects are located closely, we often observe interreflection on the object surfaces. The interreflection is accompanied by a change in the appearance of the object surfaces. In this paper, we propose a method to estimate the spectral image components from the captured images of two closely apposed objects. A spectral imaging system is used for image capturing of both objects under uniform illumination. First, we describe the basis bispectral characteristics of a fluorescent object. Second, we model the interreflection of two objects with the bispectral characteristics. The surface appearance of each object was based on both reflected component and luminescent component. We show that the spectral composition of interreflection is determined by a series of multiplication of the Donaldson matrices of the two objects. The spectral components of one bounce interreflection can be limited to only four spectral functions. Third, an algorithm is developed to estimate the spectral image components from the observed spectral radiance images that are influenced by the interreflection. The algorithm is based on a two-step estimation procedure in which the spectral components are estimated separately in the outside and inside of the emission wavelength range. The feasibility of the proposed method is investigated using fluorescent samples in details.