1. An image processing apparatus which identifies a lesion from an image, the apparatus comprising: one or more processors: and at lease one memory coupled to the one or more processors, the at least one memory having instructions stored thereon which, when executed by the one or more processors, cause the image processing apparatus to: divide the image into a first candidate region including a core region, and a second candidate region including a ground glass opacity, wherein the first candidate region is adjacent to the second candidate region, and the first candidate region is different from the second candidate region, perform enhancement processing of pixel values of the second candidate region so as to increase a difference between pixel values of the second candidate region and pixel values in a background region, obtain combined data representing the first candidate region and data representing the second candidate region, based on pixel values of the first candidate region and the processed pixel values of the second candidate region, and identify, based on the combined data, a lesion including both the core region and the ground glass opacity, each being distinguished from the background region.