Abstract: An image pick-up device with an electronic image sensor (IS.sub.1 IS.sub.2) is described, which includes a matrix of sensor elements (SE) and a low-pass filter for suppressing image frequencies exceeding the sampling frequency of the sensor. The low-pass filter has a first, composite filter function (F.sub.com) consisting of a variable component and a constant component and the device has a second filter function (F.sub.c) in conformity with the constant component which is optically or electronically subtracted from the first filter function.

Abstract: Analog-to-digital converter comprising a plurality of sigma-delta modulators, the input of the pulse shaper of a modulator always being coupled to the input of a next modulator via a coupling filter, and the output of the modulators being connected to the summing circuit via decimators, whereas in the decimators the filter function of the coupling filters is compensated. The loop filters in the modulators are described by third-order transfer functions with real poles and zeros.