Image analysis apparatus, image analysis system, image analysis apparatus operation method to analyze brightness change of subject

摘要

An image analysis apparatus includes a processor including hardware. The processor extracts parts from each of a first image and a second image acquired after the first image, each of the extracted parts including an annular peripheral portion and a central portion having a color different from a color of the peripheral portion. The processor also sets the central portion as the analysis object region and calculates a brightness decrease degree of the analysis object region in the second image relative to the analysis object region in the first image.