1. An imaging device comprising: a plurality of spot light sources, each of which radiates a spot light to an object; an image sensor configured to generate a taken image of the object in an image area by taking an image of each line structuring the image area; and a processor configured to execute a process including: estimating an inclination of the object based on a portion of a first taken image corresponding to a first line and another portion of the first taken image corresponding to a second line, the first taken image being a taken image that is taken by the image sensor and includes the portion corresponding to the first line and the another portion corresponding to the second line; estimating, based on the inclination estimated by the estimating of the inclination, an image of the object that is to be generated when the object has the inclination and the image is taken; and correcting a second taken image based on a result of a comparison between a distance between the spot light in the portion of the first taken image corresponding to the first line and the spot light in the another portion of the first taken image corresponding to the second line and a distance between the spot light in a portion of the image estimated by the estimating of the image corresponding to the first line and the spot light in another portion of the image estimated by the estimating of the image corresponding to the second line, the second taken image being one of the first taken image and another taken image taken by the image sensor.