1. A method of coding a moving image, the method performed in a coding apparatus and comprising: receiving an image; determining at least one group of picture (GOP) to be coded according to a number of image frames in the received image; performing a three dimensional (3D) wavelet transformation on the at least one GOP; and coding results of the 3D wavelet transformation, wherein determining the at least one GOP comprises: calculating a difference between a current image frame and a corresponding previous image frame to determine the number of image frames, comparing the difference to a predetermined threshold value, determining a first of the at least one GOP including image frames up to the current image frame when the difference exceeds the predetermined threshold value, obtaining an accumulation value of the difference with respect to a consecutive number of image frames, comparing the accumulation value to a given threshold value, and determining a second of the at least one GOP including image frames up to a latest image frame not causing the given threshold value to be exceeded when the difference does not exceed the predetermined threshold value.