The discrete cosine transform of the prediction error is not necessarily calculated, rather the DCT of the original picture to be transmitted and the DCT of the temporally preceding reconstructed picture are calculated separately from one another. By comparing the amplitudes of the coefficients from the original signal with respect to the difference between the coefficients from the original signal and the reconstructed picture, a decision is made for each coefficient as to whether the coefficient of the original signal or the difference between the coefficients is transmitted.