1. A sewing machine, comprising: a creating portion that creates a projection image being an image that includes a characteristic point and that is to be projected onto a sewing object; a projecting portion that projects onto the sewing object the projection image created by the creating portion; an image capture portion that is mounted in a position being different from a position of the projecting portion and that creates a captured image by image capture of the characteristic point projected by the projecting portion; and a computing portion that computes a thickness of the sewing object based on the projection image created by the creating portion and the captured image created by the image capture portion.