1. A rendering method comprising: receiving resolution information comprising an optimal resolution for rendering images constituting a frame, a number of multi-samples, and resolution factors of the respective images; rendering the images at the optimal resolution; and adjusting a resolution of each of the rendered images based on the resolution factors and the number of multi-samples, wherein the adjusting the resolution of each of the rendered images includes merging, into a pixel, a predetermined number of samples included in one of the rendered images, based on a corresponding one of the resolution factors and the number of multi-samples, and wherein the predetermined number of samples is equal to a value obtained by dividing the number of multi-samples by the corresponding one of the resolution factors.