Abstract: An image pickup device picks up an image. An image signal in association with the image is filtered in a time axis direction using a digital low-pass filter to generate an image signal having a reduced dynamic resolution power, which is equivalent to an image signal that would be obtained at a longer exposure time. The filtered signal is then subjected to frame skipping processing to generate an output image signal having a preferred frame period. The resultant signal is equivalent to one obtained by a slow shooting.

Abstract: High frequency components of a video signal are attenuated for avoiding aliasing when the video signal is corrected by a non-linear gamma correction circuit. Such high frequency components arise from the video signal harmonics, and also are generated in image contour processing of the video signal. The high frequency components are band limited, thereby linearizing the gamma correction circuit and preventing aliasing. Up-converting the sampling frequency increases a desired band limitation area and defers the generation of high frequency components that cause aliasing. The non-linear gamma correction function is divided into a plurality of sections which are replaced by respective straight-line segments each represented by a linear expression, and gamma correction is effected with a straight-line segment corresponding to the amplitude of the digital video signal.

Abstract: Of three-color signals R′, G′ and B′, obtained as output signals of multipliers 156R, 156G and 156B, designed to effectuate luminance compression of the three-color signals R, G and B sent to input terminals 151R, 151G and 151B by multiplying the signals R, G and B with a coefficient k, in such a manner as to maintain saturation and color hue of the three-color signals R, G and B, only the saturation of color video signals represented by the three-color signals R′, G′ and B′ is compressed by first saturation compression circuits 160R, 160G and 160B so that the signal level of the signal of the three-color signals R′, G′ and B′ having the highest signal level will be the clip level.

Abstract: Of three-color signals R′, G′ and B′, obtained as output signals of multipliers 156R, 156G and 156B, designed to effectuate luminance compression of the three-color signals R, G and B sent to input terminals 151R, 151G and 151B by multiplying the signals R, G and B with a coefficient k, in such a manner as to maintain saturation and color hue of the three-color signals R, G and B, only the saturation of color video signals represented by the three-color signals R′, G′ and B′ is compressed by first saturation compression circuits 160R, 160G and 160B so that the signal level of the signal of the three-color signals R′, G′ and B′ having the highest signal level will be the clip level.

Abstract: Video signal compression apparatus for analyzing an input video signal to determine the distribution of signal levels and compressing the input signal as a function of the distribution to produce an output video signal.

Abstract: A video camera and an image enhancing apparatus which can add details without deteriorating an S/N ratio near the black level are provided. The video camera is constructed by: an image pickup device for photographing an object and generating a video signal; a signal level detecting circuit for detecting a signal level of DC components of the video signal; a detail signal forming circuit for forming a detail signal to correct an outline of an image which is expressed by the video signal by extracting partial frequency components in the video signal from the video signal; a control unit for controlling the detail signal forming circuit on the basis of an output of the signal level detecting circuit in a manner such that as a signal level of the DC components is low, frequency of the detail signal to be formed by the detail signal forming circuit becomes lower; and a mixing circuit for mixing the detail signal to the video signal.

Abstract: A solid state image pickup apparatus comprises a solid state imager having a plurality of pixels and which outputs a signal corresponding to light incident thereon, a sample and hold circuit for sampling and holding analog output signals from respective pixels of the solid state imager in response to a sampling signal, a low-pass filter connected to the analog output of the sample and hold circuit for eliminating a high frequency component therefrom so as to output a filtered signal, an analog-to-digital converter for converting the filtered signal to a digital filtered signal, a memory for storing position data indicative of a position of a defective pixel, a circuit for stopping the supply of the sampling signal to the sample and hold circuit in response to the position data indicating a defective pixel so that the output signal from the defective pixel is replaced with the analog output signal from a pixel read immediately prior thereto, an interpolating circuit connected to the analog-to-digital converter

Abstract: In a video camera having three image pickup devices in which a pixel of one channel of channels forming three primary colors is spatially displaced from other pixels of two channels by 1/2 pixel, when three primary color signals output from the three image pickup devices are converted into digital three primary color signals, an aperture signal is formed from the digital three primary color signals, the aperture signal output is added to the digital three primary color signals and a digital video signal of a predetermined format is formed from the added signal, a clock frequency of an aperture signal forming circuit is set to be twice the clock frequencies of the image pickup devices, an A/D converting circuit and a video signal forming circuit.

Abstract: A dark current correction apparatus eliminates a dark current signal component or components from an output signal of an imaging device having an array of pixels. The apparatus includes an A/D converter for digitizing the output signal, and a memory for storing level data of the digitized signal while exposure of the imaging device is controlled to be at a zero level or a uniformly illuminated level, according to whether dark current correction or white current correction, respectively, is to be performed. A dark current correction signal former generates a dark current correction signal or signals from data read out from the memory. The dark current correction signal or signals are applied to a correction circuit which processes an output signal produced by the imaging device during normal imaging operation in accordance with the correction signal or signals in order to eliminate the dark current signal component or components from that output signal.

Abstract: An image defect correcting circuit for a solid state imager arranged such that levels of output signals form respective pixels of a solid state image pickup element illuminated on its whole surface a light of uniform brightness are compared with a predetermined level, data indicative of a position of a pixel which outputs a signal of peculiar level is generated on the basis of a compared result, a video signal output from at least the pixel located at the position indicated by the position data is interpolated by using output signals of other pixels according to an interpolation processing and the output signals of the respective pixels and the video signal generated by the interpolation processing are selectively output on the basis of the position data.

Abstract: A solid state image pick-up apparatus of a CCD (charge-coupled device) type is arranged such that the charges intermittently accumulated in photo-detecting elements during one vertical period are added within a vertical shift register and then fed to a horizontal shift register. Thus, the sensitivity can be controlled by controlling the accumulation time without the moving picture felt discontinuous and the fast moving picture can be picked up without any special apparatus.