1. An information processing apparatus comprising: a processor configured to: smooth a tissue sample image obtained by staining and image 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; generate, through generating a binary image by binarizing the tissue sample image smoothed by the processor, a mask for removing a region of the stromal cells from the tissue sample image; superimpose the mask generated by the processor on the tissue sample image; and count a number of the parenchymal cells with each staining intensity contained in the tissue sample image with the mask superimposed thereon, wherein the information processing apparatus is configured to generate a diagnosis using the tissue sample image.