In a method for adjusting projected images of a projector, a first image of a projection area is captured using an image capturing unit, and a second image of the projection area is capture after a predetermined interval. A background area of the second image is determined if the projected image of the projection area is determined as a static image by comparing the first image with the second image. The second image is divided into M pixel blocks, and brightness value of each pixel block is adjusted if a color of the pixel block is approximative to a color of the background area. A projection image is generated using the adjusted image of the second image, and the generated image is projected on the projection area.