FOCAL POSITION ESTIMATION METHOD, FOCAL POSITION ESTIMATION SYSTEM, MODEL GENERATION METHOD, MODEL GENERATION SYSTEM, FOCAL POSITION ESTIMATION MODEL, AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM

A focal position estimation method is a method of estimating a focal position when in focus corresponding to an estimation target image, and includes: an estimation target image acquisition step for acquiring an estimation target image; and a focal position estimation step for estimating a focal position when in focus corresponding to the estimation target image and according to a position in the estimation target image, from the estimation target image acquired in the estimation target image acquisition step, by using a focal position estimation model that is generated through machine learning training and that receives information based on an image as its input and outputs information indicating a focal position when in focus according to a position in the image.