An image processing apparatus stops hindering the extraction of biological information from an image obtained by a general-purpose image pickup device. The image processing apparatus 12 is configured by including a palm luminance estimation unit 6 and a surface reflected component enhancement unit 7 that separate low-frequency components from a signal indicating luminance values of pixels of an input image, a denoising processing unit 13 that executes a denoising process for the signal from which the low-frequency components have been separated, and a merging unit 9 that generates an image by merging the signal after the denoising process and the low-frequency components.