To determine the noise contained in a picture, it is proposed first to determine homogeneous picture regions of the picture (100-102) and then to measure the high-frequency signal component in these homogeneous picture regions (BR). The measurement of the high-frequency signal components is here averaged over many measurement points, i.e. over many homogenous picture regions (BR), and is processed into a noise figure (NOISE_SUM) (103-104). In this way, the quality of the picture can be measured directly in the picture content.