Abstract: An adaptation of an aspect ratio of a picture signal is effected by providing (1) a second derivative (D2) of an expansion factor (EF) in response to at least one constant value (C1, C2), by providing (3-13) a first derivative (D1) of the expansion factor (EF) in response to the second derivative (D2), by providing (14-21) the expansion factor (EF) in response to the first derivative (D1), and by expanding the picture signal in dependence upon the expansion factor (EF) to adapt the aspect ratio of the picture signal, whereby use of an expansion factor (EF) less than one results in a compression of said picture signal.

Abstract: An image is sampled at a given sampling frequency. For each original sample at least one additional sample delayed relative to the first sample is generated (12, 14, 16). The original samples are non-linearly processed (18) and the additional samples are non-linearly processed (20) independently of the processing (18) of the original samples. The output signals from the two processing stages are downsampled (22) back to the original sampling frequency and are metered if required for correcting the overall amplitude and phase vs. frequency characteristic.