1. An image predictive coding method comprising: sampling an image signal into a plurality of blocks; transforming the image signal of the blocks into a two-dimensional array of DCT coefficients having a DC coefficient and AC coefficients; quantizing the two-dimensional array of DCT coefficients into quantized DCT coefficients; and predicting a quantized DC coefficient and quantized AC coefficients of a current block from DCT coefficients of an immediately adjacent block adaptively selected from either a left block or an above block.