1. An image predictive decoding method for decoding an input bitstream including variable length coded transformed coefficients, the method comprising: decoding the variable length coded transformed coefficients into a one-dimensional array of transformed coefficients; adaptively selecting a prediction block for a current block from either an above block or a left block immediately adjacent to the current block; predicting a quantized DC coefficient of the current block from a quantized DC coefficient of the prediction block adaptively selected from either the above block or the left block; and further predicting quantized AC coefficients of the current block from either set of quantized AC coefficients of: (a) a first column of the left block when the left block is selected in the quantized DC coefficient prediction of the current block; or (b) a first row of the above block when the above block is selected in the quantized DC coefficient prediction of the current block.