Provided is an image processing apparatus, which is configured to perform smoothing processing on a mapping image obtained by detecting a signal emitted from one of a plurality of analysis areas of a specimen. The image processing apparatus includes: a memory; and a processor configured to execute a program stored in the memory to perform: processing for calculating a difference between a maximum value and a minimum value of signal intensity data being intensity information on the signal of one of pixels within the mapping image, and determining a degree of smoothing to be used for the smoothing processing based on the difference; and processing for performing the smoothing processing based on the determined degree of smoothing.