Abstract: A method of processing images of at least one living being, includes obtaining a sequence (19) of digital images taken at consecutive points in time. At least one measurement zone (26) comprising a plurality of image points is selected. For each measurement zone (26), a signal (28,30) representative of at least variations in a time-varying value of a combination of pixel values at at least a number of the image points for use in determining at least one of a presence and a frequency value of at least one peak in a spectrum of the signal (28,30) corresponding to a frequency of a periodic physiological phenomenon is obtained. The step (25) of selecting at least one measurement zone (26) includes analyzing information based on pixel data of a plurality of image parts in at least one of the images (19), each image part including at least one image point, and selecting each measurement zone (26) from contiguous parts determined to have similar characteristics.

Abstract: A method of processing images of at least one living being, includes obtaining a sequence (19) of digital images taken at consecutive points in time. At least one measurement zone (26) comprising a plurality of image points is selected. For each measurement zone (26), a signal (28,30) representative of at least variations in a time-varying value of a combination of pixel values at at least a number of the image points for use in determining at least one of a presence and a frequency value of at least one peak in a spectrum of the signal (28,30) corresponding to a frequency of a periodic physiological phenomenon is obtained. The step (25) of selecting at least one measurement zone (26) includes analyzing information based on pixel data of a plurality of image parts in at least one of the images (19), each image part including at least one image point, and selecting each measurement zone (26) from contiguous parts determined to have similar characteristics.

Abstract: One of the problems in display devices is that the black level is different for each type of display tube and is also dependent on temperature and ageing. The display devices hitherto known with black level setting circuits apply one control voltage to the relevant cathode during the field blanking interval, whereafter the cathode current is measured and subsequently compared with a reference current. Subsequently, the black level is adapted until the measured current approximately corresponds to the reference current.The display device now includes a black level setting circuit with a control circuit adapted to successively apply at least two control voltages in a predetermined ratio to the cathode. Moreover, the black level setting circuit includes a correction circuit for supplying a correction value dependent on the ratio between the currents generated in the relevant cathode in response to the at least two control voltages.