IMAGE PROCESSING APPARATUS AND COMPUTER PROGRAM PRODUCT

An image processing apparatus includes a spectral-characteristic estimating unit that estimates, based on a pixel value of a pixel of a stained sample image, a spectral characteristic value of each wavelength at a corresponding point on a stained sample corresponding to the pixel, the stained sample image being obtained by imaging the stained sample that is stained with a plurality of dyes. The image processing apparatus also includes a weight setting unit that sets a weight value of each wavelength based on the spectral characteristic value of each wavelength estimated by the spectral-characteristic estimating unit; and a weighted dye-amount estimating unit that estimates an amount of dye at the corresponding point on the stained sample as a weighted dye amount based on the spectral characteristic value of each wavelength estimated by the spectral-characteristic estimating unit using the weight value of each wavelength.