Abstract: A fixed-pattern noise elimination apparatus 4 eliminates a fixed-pattern noise component resulting from dark current out of an image signal outputted from an effective pixel of a solid-state image sensor 2 during image sensing, by using: a first dark current that is calculated based on a previously acquired signal outputted from a light-shielded pixel of the solid-state image sensor 2 and that is stored in a compensation data memory 6; a second dark current that is calculated based on a previously acquired signal outputted from the effective pixel of the solid-state image sensor 2 with no incident light and that is stored in the compensation data memory 6; and a third dark current that is calculated based on a signal outputted from the light-shielded pixel of the solid-state image sensor 2 during image sensing. With this configuration, a fixed-pattern noise component resulting from dark current can be effectively eliminated irrespective of the temperature of the solid-state image sensor.

Abstract: A brightness level converting apparatus improves a contrast of an image represented by an image pickup signal output from a logarithmic conversion solid-state image pickup device, so as to obtain a natural image. For this purpose, the brightness level converting apparatus converts brightness levels in the image pickup signal output from the solid-state image pickup device which logarithmically converts an incident light quantity. In the brightness level converting apparatus, a brightness level converting section converts the brightness levels in the image pickup signal by using a brightness level converting function expressed by an S-shaped curve which indicates the relation between an input brightness level and an output brightness level and includes one inflexion point. Therefore, the contrast in a low brightness level range in the image pickup signal is reduced. At the same time, the contrast in a high brightness level range is reduced while appropriately keeping a gradation.

Abstract: A sample-hold circuit, which is constituted by a capacitor and a differential amplifier or a capacitor and an inversion amplifier, is provided with a first switch for short-circuiting the input and output, a second switch for switching the input-side terminal of the input capacitor to a reference voltage input, a third switch for switching the output-side terminal of the feedback capacitor to the reference voltage input, and a fourth switch for switching the input-side terminal of the input capacitor to an input voltage; thus a refreshing operation is available. Consequently, it is possible to compensate for deviations in offset voltage that are inherently caused by process deviations of MOS amplifiers, and to improve the precision of the output of the matched filter.