1. An information processing apparatus comprising: an image processing unit for smoothing a tissue sample image obtained by staining and then imaging a biological tissue containing parenchymal cells and stromal cells so that luminance values of cell components of each of the parenchymal cells become less than those of each of the stromal cells; and a mask generation unit for generating, through generating a binary image by binarizing the tissue sample image smoothed by the image processing unit, a mask for removing a region of the stromal cells from the tissue sample image, wherein a value according to luminance values of surroundings of the cell components of each of the parenchymal cells is subtracted from the luminance values of the cell components of each of the parenchymal cells, and a value according to luminance values of surroundings of the cell components of each of the stromal cells is added to the luminance values of the cell components of each of the stromal cells in the smoothing of the tissue sample image by the image processing unit, and wherein a diagnosis based on the tissue sample image is supported.