1. A projection system comprising: a projection apparatus that projects pattern light onto an object, the pattern light including pattern images corresponding to information that indicates coded projection coordinates in a projection coordinate system, the pattern images including a first pattern image and a second pattern image, the first pattern image including two or more continuous areas including a first continuous area having a first color and a second continuous area having a second color, the first continuous area touching the second continuous area, the second pattern image including two or more continuous areas including a third continuous area having the first color, a fourth continuous area having the second color, and a fifth continuous area having the first color, the fourth continuous area touching the third continuous area and the fifth continuous area, and a total number of the two or more continuous areas of the first pattern image being different from a total number of the two or more continuous areas of the second pattern image; an imaging apparatus that captures images created on the object by projecting the pattern light projected onto the object and that generates captured images including imaging pixel values at imaging pixel coordinates in an imaging coordinate system; and an image correction apparatus that generates, based on the captured images, coordinate conversion information which associates the projection coordinates with the imaging pixel coordinates and that corrects a projection image, which is prepared in advance, by using the coordinate conversion information, wherein a width of the first continuous area, a width of the second continuous area, a width of the third continuous area, a width of the fourth continuous area, and a width of the fifth continuous area are identical, wherein a length of the first continuous area is longer than a length of the third continuous area, and wherein the length of the first continuous area is longer than a length of the fifth continuous area.