An image correction apparatus, method and medium which can perform color component correction and geometric correction using the property of a projector projecting light of a plurality of color components of an input image at different times is provided. The image correction method includes sequentially projecting light of a plurality of color components of an input image onto a projection surface at different times, acquiring color components of the projected light, and correcting the input image by comparing the acquired color components with the color components of the input image.