Moving beyond color: The case for multispectral imaging in brightfield pathology

A multispectral camera is capable of imaging a histologic slide at narrow bandwidths over the range of the visible spectrum. While several uses for multispectral imaging (MSI) have been demonstrated in pathology there is no unified consensus over when and how MSI might benefit automated analysis. In this work, we use a linear-algebra framework to investigate the relationship between the spectral image and its standard-image counterpart. The multispectral ldquocuberdquo is treated as an extension of a traditional image in a high-dimensional color space. The concept of metamers is introduced and used to derive regions of the visible spectrum where MSI may provide an advantage. Furthermore, histological stains which are amenable to analysis by MSI are reported. We show the Commission internationale de l´eclairage (CIE) 1931 transformation from spectrum to color is non-neighborhood preserving. Empirical results are demonstrated on multispectral images of peripheral blood smears.