A picture coding method is provided comprising the steps of translating the data of an image into 3-dimensional blocks and detecting their movements, in which the transform coefficients of high degree in the space associated with the 3-dimensional blocks where more movement is involved are removed for reducing spatial resolution while maintaining time resolution and also, the transform coefficients of high degree in the time associated with the 3-dimensional blocks where less movement is involved are removed for reducing tine resolution while maintaining spatial resolution, so that the effective compression of the data can be imple­mented without a great visual degradation in the picture quality.