A method and an apparatus for calculating source image coordinates. In an embodiment, a variation rate of the source image coordinate with respect to a converted image coordinate is calculated by a recursive computation, and variation rates are accumulated to obtain the source image coordinate. Because the converted image coordinate sequentially increases one-by-one, the variation rate may be obtained by using adding operations of previously obtained source image coordinate, rather than multiplying operations with the all of the converted image coordinates. Therefore, the source image coordinates may simply and effectively be calculated.