The embodiments of the disclosure set a condition when image data is generated, in association with a position of image data. An image processing device makes a plurality of light emission states of a plurality of light emitting units different according to an illumination condition, and acquires a plurality of pieces of image data obtained by imaging in the plurality of different light emission states. The image processing device generates image data to be used for image measurement from a plurality of pieces of acquired image data on the basis of a generation condition defined in association with a position in the image data. In the image processing device, at least one of the illumination condition and the generation condition is determined so that the generated image data becomes image data suitable for a purpose of the image measurement.