Abstract: For a digital imaging device having automatic gain control, a system and method have been provided for noise compensation in low-light conditions. The method comprises: receiving digital image information; compressing the image information; supplying the compressed image information; monitoring an automatic gain control signal; comparing the monitored gain control signal to a predetermined threshold gain value; in response to monitoring a high gain control signal, selecting a low-light processing algorithm; and, in response to the low-light algorithm, controlling the volume of the supplied compressed image information. Selecting a low-light processing algorithm includes selecting an algorithm that limits decreases in the compression ratio by changing parameters in a compression algorithm. Alternately, the low-light processing algorithm, prior to compressing, filters noise from the received digital image information.

Abstract: An image sensor comprises a plurality of pixel sensors, e.g., CMOS pixel sensors, including a plurality of dark pixels. A dark level compensation circuit that controls an offset applied to an image signal generated by a pixel sensor responsive to an aggregate dark level metric, e.g., a mean dark level, derived from dark pixel image signals produced by the dark pixel sensors. For example, the dark level compensation circuit for CMOS image sensor using a column parallel architecture may generate an offset control signal that varies an offset of a reference signal used by an analog to digital converter (ADC) circuit that converts an analog image signal from a pixel sensor to a dark level compensated digital image signal.

Abstract: Disclosed herein is a digital video camera for storing video derived from amplified image data.

Abstract: In one embodiment, the invention involves a method for processing an image. A sensor output is provided. An automatic gain control of the sensor output is performed to generate a first output. An automatic white balance correction to the first output is performed to generate a second output. A gamma correction of the second output is performed to generate a third output. A color interpolation is performed to the third output to generate a fourth output. A low-pass spatial filtration of the fourth output is performed to generate a fifth output. A color saturation and correction of the fifth output is performed to generate a sixth output, and a high-pass spatial filtration of the sixth output is performed to generate an image output.

Abstract: Images are sharpened and corrected for position dependent blur by providing a sharpening function which is adapted to operate upon signals corresponding to a selected number of pixels, providing a plurality of values which are a function of the position dependent blur; and applying the plurality of values to the sharpening function to modify the sharpening function so that after the modified sharpening function is applied to the image, a sharpened image will be provided which has been corrected for the position dependent blur.

Abstract: An imaging system for achieving enhanced image detail includes a sensor subsystem, an electronic image processing subsystem, and an automatic gain control (AGC) unit. The sensor unit is operative for sensing an image received from an exterior environment and for converting the image to an electrical representation having a peak value that is related to the dynamic range of the image. The electrical representation is then processed in the electronic image processing subsystem using a unique multiple order, non-linear transfer function that processes the signal in a manner that is dependent upon the dynamic range of the input image. The output signal of the electronic image processing subsystem is then applied to the AGC unit which performs a conventional AGC function on the signal. Thus, the imaging system automatically adjusts to changing scene content in the input image in a dynamic manner.

Abstract: A video signal processing apparatus capable of improving signal level while reducing noise component no matter a video signal of what illuminance is input is provided, which apparatus includes a video signal amplifying circuit amplifying an input video signal and outputting a video signal of a predetermined image size in accordance with a gain control coefficient, a frame addition circuit connected to the video signal amplifying circuit for adding outputs of the video signal amplifying circuit by a predetermined number of frames, a first signal level detecting circuit connected to the video signal amplifying circuit and calculating the gain control coefficient and a multiplication coefficient in accordance with an output of the video signal amplifying circuit, and a first multiplier connected to the frame addition circuit and the first signal level detecting circuit and receiving as inputs an output of the frame addition circuit and the multiplication coefficient.

Abstract: One embodiment of the present invention includes a temperature sensor with current mode output utilized within a cathode ray tube (CRT)-based display system for providing thermal protection to a CRT driver. Specifically, the current mode output temperature sensor of the present embodiment is implemented with the CRT driver of the CRT display system. Furthermore, the temperature sensor has a current sink output that is connected to an Automatic Brightness Limiter (ABL) circuit of the CRT display. The current sink of the temperature sensor operates in a manner similar to an “OR gate” with the CRT anode current. As such, when the CRT driver temperature rises above a threshold temperature, the current mode output temperature sensor sinks a current and activates the ABL circuit. As a result, the video amplitude of the CRT driver is reduced and its temperature is stabilized.

Abstract: A monochrome camera system, includes a processor for producing an image signal, a first circuit for selectively adjusting an overall gain of the image signal produced by the processor, and a second circuit, coupled to the processor. The second circuit selectively adjusts a gain of a portion of the image signal within a predefined region of a field of the image without affecting an overall gain set by the first circuit of other portions of the image field.

Abstract: The present invention relates to an image processing circuit and an image processing method, and is applied to, for example, a video camera, an electronic still camera and the like, for compressing the dynamic range at a high compression rate with evading the lowering of an impression concerning the contrast and the unnatural edge emphasis. The present invention smoothes an input image X while preserving the edge to obtain a gain correction coefficient, and corrects the pixel value x(i, j) of the input image X with the gain correction coefficient.

Abstract: A video signal processing circuit in which nearly 100% of a largest possible dynamic range can be used, desired contrast is obtained, and desired brightness characteristics are obtained by an increasing in luminance of a screen. The circuit has an RGB amplifier which amplifies three primary color video signals R, G, and B by a predetermined gain and in which the gain is controlled by a gain control signal, A/D converters for converting analog three primary color video signals which are generated from the RGB amplifier into digital signals respectively, inverse gamma correcting circuits for effecting an inverse gamma correction to the three primary color digital video signals respectively, an OR circuit and a peak holding circuit for detecting peak levels of the analog three primary color signals, and a gain control signal generator for generating a gain control signal in accordance with the peak levels.

Abstract: Aiming to improve color reproducibility of a red part having high color saturation, a gamma compensation apparatus of the present invention is composed of a bending point setting block 100a and a gamma compensation block 101a and bending point setting block 100a is composed of a high APL detection circuit 1a inputting an average picture level of an input luminance signal and for detecting and taking out a signal component higher than a designated level; a gain controller 2a for gain controlling the detected signal at the high APL picture detection circuit; and an adder 3a for adding a designated offset to the output of gain controller 2a, and gamma compensation block 101a is composed of a slice circuit 4a inputting a color difference signal (R-Y) and the output of bending point setting block 100a and taking out a color difference signal component higher than the output signal level of bending point setting block 100a; a gain controller 5a for adjusting the output level of slice circuit 4a; and a subtracter 6a

Abstract: The invention provides methods and apparatus for reducing the bandwidth of a multichannel image. In one aspect, the methods and apparatus call for acquiring a multichannel training image representing a training scene. Weighting factors for the respective channels are determined based on the contrast at corresponding locations in that multichannel training image. A reduced bandwidth runtime image is generated from the multichannel runtime images as a function of (i) the weighting factors determined from the training image and (ii) a multichannel image representing the runtime scene.

Abstract: A level compression and/or gradation conversion of a video signal are performed without causing any change in the hue of a picture represented by that video signal. The knee compression and/or gradation conversion are carried out by multiplying red, green and blue primary color signals by a luminance gain, while the hue and saturation remain unaffected. If the level of any of the primary color signals still exceeds a predetermined threshold level, the saturation conversion is executed by using the saturation gain and the luminance component supplied from a controller. In the saturation conversion operation, the maximum level of at least one of the red, green and blue primary color signals is made coincident with the predetermined threshold level while the hue and luminance of the picture represented by the video signal are maintained unchanged.

Abstract: A clamping circuit for use in a video camera varies a level of an image signal utilizing an analog feedback control signal, converts the varied image signal to a digital image signal, generates a digital zone value signal that corresponds to a level of a reference zone of the digital image signal, digitally detects an amount of error between the digital zone value signal and a predetermined zone value having a non-zero fractional portion, generates from the detected amount of error a digital error signal that has a predetermined number of data bits, switches between a coarse adjustment mode and a fine adjustment mode of the clamping circuit in accordance with a level of the digital error signal, generates, in the coarse adjustment mode, a pulse width modulated signal from the most significant bits of the digital error signal, generates, in the fine adjustment mode, the pulse width modulated signal from the least significant bits of the digital error signal, and generates from the generated pulse width modulat

Abstract: A gradation compensation circuit for gradation compensating the luminance level of the image signal is disclosed. An image evaluator evaluates the amount of backlighting and normal lighting in the overall image, and defines the degree of gradation compensation to be applied by the gradation compensation circuit according to the result of image evaluation. An AGC circuit maintains the overall luminance of the image constant. When the AGC control signal applied to the AGC circuit is high, the degree of compensation is suppressed, but when the AGC control signal is low, the degree of compensation is used without being suppressed.

Abstract: In an automatic gain control loop circuit supplied with two channel signals alternately input thereto, a first capacitor filter and stores the first signal output from the level detector circuit, and a second capacitor filters and stores the second signal output from the level detector circuit. The second signal is output only during the signal period of a second channel included in the two channels. An adder adds the second signal stored in the second capacitor to the first signal stored in the first capacitor. A switch selects the first signal stored in the first capacitor during the signal period of the first channel, and selects an output from the adder during the signal period of the second channel. The selected signal is fed back to the gain control input terminal of the variable-gain amplifier circuit. With there features, a flicker is prevented from occurring when the two channel signals are switched.

Abstract: An image reading apparatus in which reference density data corresponding to a reference document having a predetermined reference density is stored in advance, while a plurality of gamma correction curves are also stored in advance. Light intensity data indicative of the intensity of light reflected from the reference document is subjected to a shading correction. One gamma correction curve is selected from the plurality of gamma correction curves in correspondence to a difference in output level between the reference density data and outputted density data obtained by converting the shading corrected light intensity data. Gradation of the outputted density data is adjusted based on the selected gamma correction curve.

Abstract: A method and apparatus for removing low frequency noise and any offsets common to a plurality of samples of a signal, for calibrating an offset level to be added to the signal to reference the signal to a desired reference level at an output of the apparatus, and for clamping an input voltage level to the apparatus to a desired voltage within an operating range of the apparatus. The apparatus includes a correlated double-sampling circuit which takes a first sample and a second sample of the analog signal, takes a difference between the first sample and the second sample to remove low frequency noise and any offsets common to both sample and which outputs a difference signal. In addition, the apparatus includes a black level correction circuit which adds an offset level to the difference signal to calibrate the offset level to be added to the difference signal so that the difference signal is at a desired reference level at an output of the apparatus.

Abstract: Apparatus that performs automatic gain control (AGC) for an electronic imaging camera, especially in outdoor surveillance applications. A fiber optic link is used to collect ambient light and couple this light onto a small portion of a light sensing array of the camera. A reference voltage produced by the light sensing array in response to the light from the fiber is used by AGC circuits in the camera to control the integration time of light sensing elements of the array, the gain of the camera's video amplifier, and lens aperture, if necessary. These camera gain controls are adjusted to maintain the reference voltage derived from the light provided by the fiber optic link to be within a predefined range as the ambient light level varies due to weather conditions and time of day. Methods of providing automatic gain control correction are also disclosed.

Abstract: An inexpensive AGC apparatus capable of concurrently satisfying a sufficient impedance matching characteristic and a linear AGC characteristic is provided. The AGC apparatus is provided with a linear correction circuit. The linear correction circuit corrects a control voltage from a control voltage generator circuit, and outputs a corrected control voltage to a variable gain amplifier circuit. The above-mentioned correction is such a correction that a variation of a decibel value of an AGC gain relative to a variation of the control voltage is linearized.

Abstract: An exposure device controls the exposure of an image in a video camera using a vibration control system. The gain of an iris, which receives the image, the gain of an AGC amplifier, which amplifies the sensed image and the gain of an electronic shutter, which controls the speed at which images are sensed; are controlled by driving the iris in a first range indicative of an object illuminance when a hand vibration correcting operation is performed, driving the AGC amplifier in a second range indicative of the object illuminance, and driving the shutter in a third range indicative of the object illuminance.

Abstract: A system for generating a digital output signal representing a captured image includes a sensor for capturing the image and generating a sensor output signal. A gain control amplifier is coupled to the sensor and receives the sensor output signal. The gain control amplifier has controls for applying various levels of gain to the sensor output signal. An analog-to-digital converter is coupled to the gain control amplifier and generates the digital output signal representing the captured image. A processor is coupled to the analog-to-digital converter and the gain control amplifier. The processor provides a control signal to the gain control amplifier for adjusting the level of gain applied by the amplifier.

Abstract: A background region of the current image is compared to a reference region to characterize the gain associated with the current image. The values of the unsaturated background pixels of the current image are then adjusted to correct for the characterized gain before encoding the current image. In a preferred embodiment, the reference region is generated based on the previous n frames in the video sequence.

Abstract: A smear correction circuit for elimination of smear error within image sensing devices wherein image receiving means receive CCD image data, a determination of a smear scaling factor for smear estimation is made, the smear scaling factor being determined by a ratio of smear error per given level of illumination. The smear estimation means provide for the determining of a value for smear estimation on a per line basis. Adjustment of the image data is made corresponding to the smear estimation and dark level correction values prior applying the adjusted data to gain adjustment circuitry.

Abstract: A digital black clamp circuit for calibrating the black level of an image signal produced by an imaging device, such as a CCD sensor. The digital black clamp circuit comprises a source of a video signal having a first interval of black level pixels and a second interval of image pixels; a differential amplifier having first and second inputs and an output, wherein the source is coupled to one of the first and second inputs; an A/D converter coupled to the output of the differential amplifier; a digital signal processor coupled to the A/D for accumulating and averaging digital black level pixels; a D/A converter coupled to the digital signal processor; and a control for selectively uncoupling the D/A converter to the other of the first and second inputs of the differential amplifier during the first interval of the video signal; and for coupling the D/A converter to the other of the first and second inputs during the second interval of the video signal to clamp the image pixels to an average black level.

Abstract: An image pickup device comprises variable gain control circuits 11-13 and 23-25 for respective channels of digital color signals and luminance signals to control the gains by a gain control signal SG. Since the gains are variable in the digital signal channels, the deterioration of the image quality is reduced. The number of input bits of the variable gain control circuits is larger than the number of output bits to minimize the deterioration of the signal due to the loss of digits in coefficient circuits in the variable gain control circuits.

Abstract: A linear sensor camera comprises an image information converter for receiving image information, electronically scanning the image information, and converting the scanned image information into an electric signal having a regular period. The spatial frequency modulation of the electric signal output from the image information converter is determined for one scanning period, and the quantity of the electric signal is controlled in accordance with the spatial frequency modulation determination. When the spatial frequency modulation is low, the quantity of the outputted electric signal is decreased, thereby permitting the image information processing speed to be increased.

Abstract: A system for generating a digital output signal representing a captured image includes a sensor for capturing the image and generating a sensor output signal. A gain control amplifier is coupled to the sensor and receives the sensor output signal. The gain control amplifier has controls for applying various levels of gain to the sensor output signal. An analog-to-digital converter is coupled to the gain control amplifier and generates the digital output signal representing the captured image. A processor is coupled to the analog-to-digital converter and the gain control amplifier. The processor provides a control signal to the gain control amplifier for adjusting the level of gain applied by the amplifier.

Abstract: A digital camera for processing a digital signal. The camera includes an image signal processing circuit which uses a low-resolution analog-to-digital converter. The processing circuit performs AGC and gamma control on both digital and analog signals. Gain control and gamma control are performed by auto gain controllers which either process an analog signal prior to converting the analog signal to a digital signal or after the analog signal is converted to a digital signal. The image signal processing circuit performs processing based on the output of one of a m-bit output of an AGC/gamma controller and a m-bit output of an A/D converter. The AGC/gamma controller receives an n-bit clamped image signal from a clamper, while the m-bit A/D converter receives an analog input. This selection operation minimizes the need for a high-resolution A/D converter.

Abstract: A non-linear circuit having a transfer characteristic which is adjustable per amplitude segment of an input signal (Yi) includes a segmenting circuit (11 . . . 15, 21 . . . 25) for obtaining a plurality of amplitude segment signals (Y1 . . . Y5) from the input signal (Yi), and a non-linear segment amplifier circuit (31 . . . 35) coupled to the segmenting circuit (11 . . . 15, 21 . . . 25) for separately multiplying segments (Y1 . . . Y5) of the input signal (Yi) by respective segment gain factors (HM1 . . . HM5) in dependence upon a common gain factor (HMa) derived from the segment gain factors (HM1 . . . HM5) and on the basis of the amplitude segment signals (Y1 . . . Y5) for supplying a signal (Y"s) which is adjustable per amplitude segment of the input signal (Yi). The non-linear circuit may also include an output circuit (37, 39) coupled to the non-linear segment amplifier circuit (31 . . .

Abstract: A digital electronic still camera operable in a text mode for clearly shooting a bilevel image, e.g., characters printed or formed on a document. A luminance signal can be roughly corrected with respect to shading by a simple circuit arrangement. This corrects a decrease in the quantity of light in the peripheral portion of a frame and thereby renders characters or similar bilevel images in a picture highly legible.

Abstract: An image pickup apparatus includes an image sensor for simultaneously reading signals of adjoining two horizontal pixel rows by one-time horizontal scan; an electronic zoom circuit for enlargement-processing an output signal of the image sensor; an operation switch for instructing for on/off control of electronic zoom operation; and a scan method switching circuit for controlling scan method of the image sensor according to with an instruction from the operation switch. The scan method switching circuit exerts control so that, when the electronic zoom operation is turned on, a pair of two horizontal pixel rows to be read simultaneously in the odd and even fields are made identical, and when the electronic zoom operation is turned off, a pair of two horizontal pixel rows to be read simultaneously in the odd and even fields are shifted by one row in the vertical direction.

Abstract: An average luminance Y is added to a correction coefficient by an adder. The correction coefficient characterizing the gradation correction characteristic of input picture signals of a picture is determined easily according to feature quantities extracted from input picture signals. A first gradation correction characteristic and a second gradation correction characteristic are added to a weight according to the correction coefficient and a correction gain of the gradation correction characteristic is determined. Thus, gradation can be corrected for all kinds of pictures including front-lit and back-lit objects. Further, by using the average luminance Ya, gradation is corrected in pixel units so as to keep contrast and to send an output signal with good gradation. A quantizer in the correction coefficient determination circuit quantizes the level distribution of the luminance signal and the correction coefficient determination circuit provides the correction coefficient according to the quantized value.

Abstract: The white peak level and black peak level of each of three types of color signals R, G and B obtained by picking up a negative image are detected. The amplitudes and levels of the signals are adjusted in such a manner that the white peak levels of the color signals R, G and B coincide as well as the black peak levels of these color signals. Signals representing the detected white peak and black peak levels are superimposed in first-half and second-half portions of a blanking interval of each of the color signals R, G and B. The signals that result can be utilized in subsequent signal processing. Also, the input/output characteristics of a gamma correction circuit are represented by an exponential function, which is for a gamma correction, up to a fixed input range, and by a KNEE curve, whose slope is smaller than that of the exponential curve, in a range beyond the fixed input range.

Abstract: An automatic gain control circuit for processing a reproduced color signal in a VCR which may include first and second feedback loops respectively positioned before and after a comb filter. In the first feedback loop, the color signal is amplified by a first variable gain amplifier and supplied to both a first burst detector and the comb filter via a frequency converter and a band-pass filter. The first burst detector detects the peak level of the burst signal included in the color signal and controls the gain of the first amplifier for stabilizing the level of the burst signal. The comb filter removes cross-talk components from the color signal and supplies an output signal to the second feedback loop. In the second feedback loop, the output signal is amplified by a second variable gain amplifier and supplied to a second burst detector.

Abstract: A system for generating and displaying a contrast false color overlay as a focus assist includes a signal divider, an automatic gain control unit, an adder, a signal reducer and a signal combiner. The signal divider receives a signal representing an image and divides the signal into a red channel signal, a green channel signal and a blue channel signal. The red, green and blue channel signals are input to the signal reducer and respectfully reduced by a percentage value. The reduced Green and Blue channel signals are input to the signal combiner and combined with the output of the adder. A luminance signal is also input or generated from the channel signals and is fed to the automatic gain control unit which produces a contrast signal whose brightness is proportional to the contrast in the image. The contrast signal is input to the adder along with a reduced version of the red channel signal where the two signals are added together, and the output of the adder is provided to the combiner.

Abstract: The white peak level and black peak level of each of three types of color signals R, G and B obtained by picking up a negative image are detected. The amplitudes and levels of the signals are adjusted in such a manner that the white peak levels of the color signals R, G and B coincide as well as the black peak levels of these color signals. Signals representing the detected white peak and black peak levels are superimposed in first-half and second-half portions of a blanking interval of each of the color signals R, G and B. The signals that result can be utilized in subsequent signal processing. Also, the input/output characteristics of a gamma correction circuit are represented by an exponential function, which is for a gamma correction, up to a fixed input range, and by a KNEE curve, whose slope is smaller than that of the exponential curve, in a range beyond the fixed input range.

Abstract: An automatic gain and level control method and circuit. In general, the inventive method includes the steps of detecting the DC level of a signal and providing a first signal in response thereto and detecting the AC amplitude or gain of the signal and providing a second signal in response thereto. A DC level error signal is generated in response to the first signal. An AC amplitude error signal is generated in response to the second signal. The DC level of the signal is corrected in response to the DC level error signal. The AC amplitude of the signal is corrected in response to the AC amplitude error signal.

Abstract: An automatic dark level zeroing circuit removes a dark level DC bias from an analog video signal generated by a charge-coupled device (CCD) camera, The automatic dark level zeroing circuit is DC-coupled to the CCD camera such that there is no loss of low frequency information in the analog video signal, The automatic dark level zeroing circuit forms an adaptive feedback loop that removes the dark level DC bias from the analog video signal by using a sampled value of the analog video signal that represents an internally masked pixel to produce a zero correction signal that is then combined with the analog video signal to remove the dark level DC bias without removing any useful video information or otherwise altering the information content of the analog video signal,

Abstract: Image processing apparatus wherein the level of an input analog picture signal from an imaging device is controlled by gain control circuitry, and the gain-controlled analog signal is then converted into a digital signal. Feedback clamping is performed by generating an error signal by subtracting a target value from the digital signal, and then adding the error signal to the gain-controlled analog signal. Correct clamping is made possible by allowing the target value to be varied based upon the gain set by the gain control means.

Abstract: A camcorder equipped with a function for correcting a brightness on sides of the camcorder screen which automatically compensates the brightness on the sides of screen is described.

Abstract: An image pickup signal processing apparatus includes an A/D converter and a nonlinear signal processing circuit for comparing an image pickup signal input to the A/D converter and a voltage obtained by dividing a reference voltage of the A/D converter and nonlinearly processing the image pickup signal. The nonlinear signal processing circuit includes a negative feedback amplifier and circuit components for changing the amount of negative feedback provided by the negative feedback amplifier to generate nonlinear characteristics.

Abstract: An integrated circuit for processing an analog image signal obtained from a CCD, etc. and converting the processed image signal to a digital image signal. The integrated circuit includes a circuit for adjusting an offset voltage included in the analog image signal, a circuit for sampling/holding the image signal from the adjusting circuit, a variable amplifier for varying an amplitude of the image signal output from the sampling/holding circuit, an analog/digital converter for converting the image signal from the variable amplifier to a digital signal, and a circuit for detecting a DC component included in the digital image signal and providing the detection result to the adjusting circuit. Correction of a DC voltage component of the analog image signal and amplitude adjustment of the analog image signal can be performed by using a single LSI, and the LSI can be connected to various types of CCDs without using an additional circuit.

Abstract: A video camera device includes an image signal level varying circuit for varying the signal level of an image signal; image signal level detecting circuit for detecting the signal level of the image signal; zoom lens position detecting circuit for detecting the position of a zoom lens; and brightness correcting circuit supplied with an output from the zoom lens position detecting means for correcting a brightness attenuating characteristic of the zoom lens responsive to the position of the zoom lens. The gain of the image signal level varying circuit is varied by an output of the image signal level detecting circuit and an output of the brightness correcting circuit.

Abstract: A suitable image signal is obtained even with regard to a subject exhibiting a very large difference in luminance between bright and dark areas. A video signal obtained from a CCD by imaging the subject is amplified by a first amplifier, converted into digital image data A by a first A/D converter and then stored in a first memory. The video signal from the CCD is also amplified by first and second amplifiers, converted into image data B by a second A/D converter and then stored in a second memory. The amplification factor of the first second amplifier is set such that a comparatively dark area of the image of the subject will assume a level having an appropriate brightness. A multiplexer selects data representing a comparatively bright area of the image of the subject from image data read out of the first memory as well as data representing a comparatively dark area of the image of the subject from image data read out of the second memory.

Abstract: A video camera includes a solid state image pickup element for converting a light image radiated thereon from an object to be photographed into an electric signal. The element is also operated as a shutter for controlling an amount of light radiated thereon by being controlled in its storage time. The video camera further includes a unit for inputting data for setting a storage time of the image pickup element, and a unit connected to the data inputting unit for controlling the storage time of the element in response to the inputted set data gradually to the set data by changing the storage time by a predetermined storage time for the lapse of every predetermined time period.

Abstract: A modular CCD includes a camera head and a camera body. The camera body includes an amplifier, an A/D converter, a D/A converter, a video simulator, a summation circuit and a switch. The switch is used to controllably switch between the output of the camera head and the video simulator output. A system is provided for adjusting the voltage supplied to the switch by the D/A converter to adjust the voltage output of the summation circuit to compensate for the difference between those outputs so that the camera body can accept different camera heads with different gain requirements.

Abstract: A circuit is provided for correcting an image signal received from a camera wherein the camera includes a plurality of charge coupled devices, each for providing a light signal indicative of the intensity of light incident thereon and wherein the plurality of light signals from the plurality of charge coupled devices are indicative of an image received by the camera. The correction circuit includes a gain memory for storing a plurality of gain correction factors wherein each gain correction factor is associated with a respective charge coupled device of the camera. The correction circuit further includes an offset memory for storing a plurality of offset correction factors wherein each offset correction factor is associated with a respective one of the plurality of charged coupled devices. The gain memory is responsive to a control circuit for multiplying the plurality of electric signals by the appropriate gain correction factor.

Abstract: An automatic knee control circuit including a knee circuit for setting a knee point and a knee slope, a detecting circuit for detecting an output signal of the knee circuit and a comparing circuit for comparing an output of the detecting circuit with a reference voltage, wherein the knee circuit is controlled on the basis of an output of the comparing circuit. This automatic knee control circuit is characterized by a distributing circuit for distributing the output of the comparing circuit by an arbitrary distributing ratio, wherein the setting of the knee point is controlled by a first distributed output and the setting of the knee slope is controlled by a second distributed output, thereby making it possible to set a wide variety of signal processing states with ease. Therefore, pictures corresponding to cameraman's intention can be produced.