Abstract: The present invention relates to a CMOS active pixel sensor which includes a compensation circuit capable of compensating a lowered pixel voltage output due to leakage current of a photodiode. The CMOS active pixel sensor having a light sensing unit for generating an output voltage when light is incident thereupon, the sensing unit having an amount of leakage current before the incidence of light. A reset unit resets the output voltage of the light sensing unit to an initial reset voltage in response to a reset signal. A sense transistor has a source, a drain coupled to a power source voltage, and a gate coupled to the output of the light sensing unit. A select transistor has a drain connected to a source of the sense transistor, and provides the voltage of the sense transistor to a bit line, in response to a select signal. A compensation unit supplies a voltage corresponding to the output voltage of the light sensing unit lowered by the leakage current.

Abstract: An image input apparatus has an image sensor for photoelectrically converting image information of an object into an electric signal and outputting the signal, and a correction circuit for adjusting a fluctuation of offset components generated during photoelectric conversion contained in the signal output from the image sensor to correct the offset components. Images of good quality can be obtained by correcting the offset components contained in the signal output from the image sensor.

Abstract: An image sensing apparatus of this invention includes a signal generator adapted to generate a signal upon reception of input light, a transfer unit adapted to transfer the signal generated by the signal generator, a temperature measuring unit adapted to measure a temperature, an amplification unit adapted to amplify the signal transferred from the transfer unit, and a control unit adapted to control the gain of the amplification unit at a first temperature to be lower that the gain of the amplification unit at a second temperature measuring unit, the second temperature being lower than the first temperature.

Abstract: A method and apparatus for adjusting, on a pixel-by-pixel basis, the gain and offset in an AFE as the pixels are sequentially processed. Although the method can be used for any purpose, it is directed in particular to light source non-linearity, such as edge effects of a scanner. A unique clocking method clocks the gain and offset values into the register at a higher clock rate than the image sampling rate.

Abstract: Image data having a high S/N ratio is obtained even when the exposure time is relatively long. To achieve the above object, there is provided an image input apparatus in which an accumulation mode is set with the shutter open, thereby acquiring image data A1. The shutter is then closed, and the accumulation mode is set to acquire subtraction data between the image data and black image data A2. This processing is repeated to acquire image data A1 and subtraction data A2, and these subtraction data are added. These operations A1, A2, and A3 are repeated a predetermined number of times to update addition data, and image processing is performed on the basis of the updated addition data.

Abstract: A method and a system for dynamically detecting and correcting anomalous pixels in the raw data taken from an image sensor array such as a CCD or a CMOS sensor array, thus allowing the use of dumb cameras to capture digital images for subsequent use by an intelligent host—such as being displayed on a computer monitor. This invention uses software algorithms running on an intelligent host processor to dynamically correct the anomalous pixels in the raw data taken from an image sensor array typical of those in a digital still or a video camera. Using the combination of a dumb camera which provides raw data to an intelligent host, which does all the subsequent image processing, the system works by scanning an image frame for pixels that vary more than a specified amount in their brightness value from their neighboring pixels and designating those as defective pixels. The location and frequency of the photosites sending the defective pixels are stored in a statistical database in the computer's memory.

Abstract: A method for reducing dark current within an image sensor includes applying, at a first time period, a first set of voltages to the phases of gate electrodes of vertical shift registers sufficient to accumulate holes of the vertical shift register, beneath each gate electrode and applying, at a second time period, a second voltage to a first set of the gate electrodes while simultaneously applying a more positive voltage to a second set of gate electrodes, the second voltage being of sufficient potential so holes that were accumulated beneath the second set of gate electrodes during the first time are collected and stored beneath the first set of gate electrodes during the second time period.

Abstract: A low cost camera by implementing the major functions in host software is provided. This is accomplished by sending raw, digitized data from the camera directly to the host. The increased volume of raw data is handled by either an improved compression/decompression scheme using lossless compression, using lossy compression or using a shared bus with higher bandwidth. By moving such functions as color processing and scaling to the host, the pixel correction can also be moved to the host. This in turn allows the elimination of the frame buffer memory from the camera. Finally, the camera can use a low cost lens by implementing vignetting, distortion, gamma or aliasing correction with a correction value stored in a register of the camera for later access by the host to perform corrections.

Abstract: In an imaging apparatus for detecting a dark output level superposed on an imaging signal which is an output signal of an imaging device and correcting the imaging signal based on the detected dark output level, occurrence of a false signal caused by the dark output correction process is prevented and a substantial lowering in the effective imaging range is prevented by eliminating a dark output component from the imaging signal and setting a clip level and gain for a subject signal component according to the detected dark output level.

Abstract: In a photoelectric converting apparatus including a sensor unit, a transfer unit, and a memory unit, noise can be minimized. The sensor unit includes a plurality of pixels each having at least a photoelectric converter and a first amplifier for amplifying a signal derived from the photoelectric converter, and a memory unit including a plurality of storage elements, for storing the signal derived from the sensor unit, each storage element having a second amplifier for amplifying a signal derived from the storage element to output an amplified signal, wherein the gain of the first amplifier is made different from a gain of the second amplifier.

Abstract: A system and method of capturing an acceptable fingerprint image is disclosed herein. The method includes a step of capturing an initial fingerprint image at a nominal image integration time. Once this initial fingerprint image is captured, a first intermediate fingerprint image at a first intermediate image integration time is captured. Next, an image darkness test is performed followed by an image definition test. If one or more of these tests indicates that the first intermediate fingerprint image is unacceptable, a subsequent intermediate fingerprint image at a subsequent intermediate image integration time is captured. This subsequent intermediate fingerprint image can be captured before the image definition test is performed. Additional intermediate fingerprint images can be captured until an image that has an acceptable darkness level as a well as an acceptable definition level is captured. Also disclosed is a fingerprint scanner that performs this method.

Abstract: A method and system for improving the quality of an image in an electronic imaging system is disclosed. The method and system comprise capturing an image frame, capturing a compressed dark frame, decompressing a portion of the compressed dark frame and subtracting the decompressed portion of the compressed dark frame from a corresponding section of the image frame. The steps of decompressing a portion of the compressed dark frame and subtracting the decompressed portion from a corresponding section of the image frame are repeated for additional portions of the compressed dark frame.

Abstract: Disclosed is an image sensing apparatus having a function of removing a dark current noise component of an image sensor. This image sensing apparatus includes an image sensor such as a CCD, at least two noise component storage areas, a CPU for controlling an operation of writing a noise component of one frame generated by the image sensor into a noise component storage area selected from the at least two noise component storage areas, and a subtracter for correcting an object image photographed by the image sensor, on the basis of the noise component stored in one of the at least two noise component storage areas.

Abstract: A solid image capturing device outputs image data and characteristic data of the solid image capturing device on the same output signal line. Both outputs are processed by the same circuit. In one embodiment, the characteristic data is optically stored in the solid image capturing device. In another embodiment, the characteristic data is non-optically stored in the solid image capturing device. The image field of the solid image capturing device includes an invalid image field located outside the effective image field. Signals output from the invalid image field include those concerning the characteristic data of the solid image capturing device.

Abstract: A method is used to perform dark current compensation in a sensor (e.g., a CCD or CMOS sensor). A first and second array of devices (e.g., pixels) in the sensor are used to determine a first dark current value. The first array of pixels in the sensor receives impinging light and generates optical energy values therefrom. The second array of pixels in the sensor are used to determine a second dark current value at substantially a same time as the generating of the optical energy values. The second array of devices being non-sensitive to the impinging light. The first and second dark current values are used to compensate the optical energy values.

Abstract: An image pickup apparatus including: CCD image pickup device; a correction reference signal generating section for generating a correction reference signal for correcting effective image signals of the image pickup device from output signals of a vertical optical black pixel portion of the image pickup device; an image signal correcting section for subtracting the correction reference signal from an effective image signal; and CCD driver having a plurality of drive modes for driving the image pickup device to read pixel charges as output signals; wherein, when generating the reference signal, said correction reference signal generating section performs different types of reference signal generation processing corresponding to the plurality of drive modes of the CCD driver.

Abstract: An apparatus has an image sensing device, an instruction device for instructing to execute a plurality of image sensing operations with different image sensing times of the image sensing device, and a signal processing device for performing a first image sensing operation for making the image sensing device perform an image sensing operation in an exposure state to obtain a sensed image signal, and a second image sensing operation for making the image sensing device perform an image sensing operation in a non-exposure state to obtain a sensed image signal, and processing the sensed image signal obtained by the first image sensing operation by the sensed image signal obtained by the second image sensing operation. The signal processing device changes the second image sensing operation in response to the instruction of the instruction device.

Abstract: A method and system for improving the quality of an image obtained by an electronic imaging system is disclosed. The method and system comprise capturing an image frame, capturing a partial dark frame and subtracting the partial dark frame from a corresponding section of the image frame. The steps of capturing a partial dark frame and subtracting the partial dark frame from a corresponding section of the image frame are repeated for additional partial dark frames.

Abstract: There is provided a method of driving an image sensor which can remove FPN resulting from inter-chip variations without requiring any dark correction. A semiconductor photosensor chip has a plurality of sensor modules mounted on a mounting substrate, and a semiconductor device in which at least an N signal input buffer circuit for receiving N signals, an S signal input buffer circuit for receiving S signals, a differential circuit for calculating any difference between the outputs from the N and S signal input buffer circuits, and a voltage clamping circuit for clamping the output from the differential circuit are formed on a single semiconductor substrate, and the voltage clamping circuit clamps the reset state of S and N signal common output line.

Abstract: An image processing apparatus (200) for a charge coupled device including analog front end circuitry having optical black and offset correction, whereby the offset and optical black correction circuit is programmable. The present invention includes a first circuit (202, 204, 206, 208, 210) to sample the incoming optical black signal output from a CCD. This first circuit includes a correlated double sampler (202) coupled to a first programmable gain amplifier (204). An adder (206) connects between the first programmable gain amplifier (204) and a second gain amplifier (208) for adding in the optical black offset to the optical black signal input from the CCD. A second circuit (212, 214) includes a reverse programmable gain amplifier (212) connected to the output of the second programmable gain amplifier (208) to amplify the optical black level inversely proportional to the gain from the second programmable gain amplifier (208).

Abstract: This invention is a digital camera that measures its internal temperature using the dark current of the photo detector. Using the temperature information the digital camera controls its internal temperature by selectively shutting down or slowing down heat generating components.

Abstract: A method and circuit for compensating variations induced by temperature, strain and manufacturing technology in CMOS video sensors. Using at least two reference CMOS sensors, held at the same temperature level as the CMOS video sensors to be compensated and which are not irradiated, two reference signals are generated whereof one corresponds to a reference dark value whilst the other one, in response to the application of an electric current, corresponds to a reference illumination value. The reference signals are amplified separately of each other. At least one correction value is stored in a memory unit for each CMOS video sensor point to be compensated, such that output signals corrected by FPN (=fixed pattern noise) will be obtained. The FPN-corrected output signals as well as the reference signals obtained are supplied to the A/D converter where the output signals of the CMOS video sensor are compensated and converted into digital signals.

Abstract: A circuit for determining the median dark level of an image sensor, the circuit comprises a first circuit for comparing a current pixel value and a cumulative median; a storage element for storing the cumulative median level; and a second circuit which utilizes the first circuit for adjusting the cumulative median based on the current pixel level input for updating the cumulative median dark level.

Abstract: An image sensor and a pixel reading method used this image sensor, in which the accuracy of a black level can be increased by that an optical black region being the black level reference of signals is read every horizontal line at a local or random access mode, are provided. And also the structure of a camera system used this image sensor can be simplified is provided. The image sensor is a MOS type image sensor composed of a pixel array region and an optical black region disposed at the one end in the pixel array region. And the MOS type image sensor provides a mode selector that selects the local access or random access mode or a frame access mode. When the local access or random access mode is activated, the image sensor decides a pixel reading region in the pixel array region. The image sensor reads information of one or more pixels having a designated horizontal line address in the pixel reading region every horizontal line address.

Abstract: A CCD and CMOS image pickup module including a circuit main board on which an image sensor (CMOS, CCD) and relevant electronic elements are laid. A lens seat is disposed on an upper edge of a package of the image sensor. The lens seat has an image pickup cylinder correspondingly positioned above a coupling transistor of the image sensor. The lens seat covers and encloses the image sensor with the connecting section of the bottom of the image pickup cylinder sealedly attaching to the periphery of the top face of the package of the image sensor. With the profile of the outer periphery of the package of the image sensor serving as a normal standard for the axis of the lens, the axis of the lens being projected onto the sensor center of the coupling transistor.

Abstract: A ranking-based automatic dark compensation circuit for efficiently estimating dark level in a CCD or CMOS image sensor. The ranking circuit comprises of k staggered comparators, each comparator having an associated temporary result register. Each comparator having two inputs, with the first input coupled to an output of the previous stage comparator and the second input coupled to its associated temporary result register. The temporary results are initialized to the largest possible dark value. At each stage, a comparison is made of a new input sample to a stored value of the temporary register. If the new sample is greater than the value of the associated temporary register, the value in temporary register is not changed and the new sample is passed to the next comparator. Conversely, if the new sample is smaller, then that new sample is stored into the temporary register, while the original temporary result is passed to the next comparator.

Abstract: A process for correcting noise level of an image detector including photosensitive points arranged in rows and in columns. Within each row, the points are distributed into detector points and into corrector points. The detector points deliver a measurement value dependent on a luminous cue to which they are exposed. The corrector points deliver a dark value serving in the correction of the measurement values. Within at least one row, the detector points are distributed into at least two groups and the measurement values are corrected with a first or a second correction value depending on the group from which they originate. Such a process may find application to digitized-image detectors.

Abstract: An integrated circuit for sampling outputs representing a pixel value comprises two first variable capacitors each having a variable range of capacitance and each for receiving the voltage representing the pixel value; two first transistors respectively connected electrically to each of the first variable capacitors for transferring the voltage to each of the variable capacitors; and a second transistor connected electrically to each of the first variable capacitors for transferring the voltage from each of the first variable capacitors.

Abstract: An image apparatus has a light-receiving section and a light-blocking section. The light-receiving section receives light from an object to generate an analog video signal. The light-blocking section blocks the light to generate reference signals. The analog video signal is converted into a digital video signal. The reference signals are accumulated a predetermined number of times from a predetermined accumulation starting point on scanning lines forming an image of the object for a specific period. The accumulated signal is averaged to generate an average signal. A reference level of the digital video signal is adjusted based on the average signal so that the difference between the digital video signal and the average signal becomes zero. The number of times for accumulation is decided as 2n that is smaller than a specific number “m”, of the scanning lines for forming the image of the object. The accumulation starting point is decided as (m?2n)/2, “n” and “m” being positive integers.

Abstract: A method and apparatus for identifying and compensating for the effects of defective pixels in high resolution digital cameras having image processing apparatus. The apparatus includes a storage system for storing data corresponding to either a dark current reference image and a white reference image and at least one actual image captured by a pixel array, and at least one processor coupled to the storage system for compensating the data corresponding to the actual image based upon the stored data. The method includes capturing and storing both dark and white reference images as well as capturing and storing actual images, identifying pixels that are affected by dark current or are defective pixels, reading data corresponding to pixels of an actual image affected by dark current or that are defective from the storage system and compensating the affected pixels.

Abstract: This invention is to provide a solid-state image pickup element including a sensor unit including a plurality of lines of photoelectric conversion units for generating charges from received light by photoelectric conversion, a memory unit including a plurality of lines of storage units for storing signals from the plurality of lines of photoelectric conversion units, a transfer unit for transferring a signal from the sensor unit to the memory unit, a control unit for causing storage units of an arbitrary block in the memory unit to output an image signal from the photoelectric conversion units and causing the photoelectric conversion units corresponding to the storage units of the arbitrary block to output a noise signal, and a subtracting unit for calculating a difference between the image signal and the noise signal.

Abstract: Method and device for the exposure-dependent noise correction in images sensor which can be addressed in lines and columns are converted into digital values and an offset voltage correction is carried out by a summer, a gain correction is carried out by a multiplier, and an exposure-dependent dark current correction is carried out by a further summer. Further, the coefficients that depend on the line number, the column number and the integration time, are determined by linear approximations. As a result, the fixed pattern noise (PFN) in CMOS image sensor can be efficiently suppressed with a relatively low outlay.

Abstract: An image processing apparatus (800) for a charge coupled device having hot/cold pixel and line noise filtering is disclosed which provides optical black and offset correction. The present invention teaches an offset and optical black correction circuit having a digital filter to obtain noise-free optical black correction for charge-coupled devices such that a digitally programmable bandwidth exists. The sum of the channel offset and optical black level is averaged for a given number of lines having a number of optical black cells per line and this sum passes through a digital filter. Moreover, the channel is digitally calibrated to obtain a user programmed ADC (810) output which corresponds to that average.

Abstract: An image sensing system includes an image sensor and a black clamping circuit which reside on the same substrate. Particular embodiments use common components for both imaging and black clamping, and digital control of an analog black clamp function.

Abstract: A CMOS imager includes a CMOS image sensor comprising an array of photoreceptors, a memory storing a reference operating level for the array, and readout circuitry for obtaining, at n-bit resolution, a photoreceptor reset value from the photoreceptors in the array. In addition, the CMOS imager includes comparison circuitry that determines a difference between the reference operating level and the photoreceptor reset value as well as matching circuitry that matches the difference against bins in a bin allocation. In particular, the bin allocation spans a photoreceptor noise range with the bins forming a quantization of the noise range into correction levels. Each of the correction levels may be associated with an m-bit correction code, where m is typically much less than n. As a result, the amount of memory necessary to store the correction codes is far less than that required to store full resolution (i.e., n-bit) values.

Abstract: An electronic still camera for determining photographing conditions from output of the solid-state imaging device by the preparative photographing operation prior to actual photographing operation and generating an actual photographing image from an output signal of the solid-state imaging device based on the photographing conditions, characterized by that the electronic camera has the solid-state imaging device, the means for reducing the read-out rate of a image signal from the solid-state imaging device at the actual photographing operation lower than the read-out rate of a image signal from the solid-state imaging device at the preparative photographing operation, and the band-width changing means for reducing the signal passing band-width at the actual photographing operation narrower than the signal passing band-width at the preparative photographing operation in the image signal path from the solid-state imaging device.

Abstract: An offset correction circuit which enables a designer to control the correction range irrespective of the amplification sought to be achieved to the image component of the input signal. The offset correction further enables the designer to perform offset correction to a low resolution. Both range and resolution can potentially be attained using only two stages thereby minimizing power consumption and also minimizing introduction of any undesirable components.

Abstract: An optically operated test structure for testing the charge transfer efficiency (CTE) of a charge coupled device (CCD) solid-state image sensor. A solid-state image sensor includes a substrate of a semiconductor material of one conductivity type having a surface. A plurality of spaced, parallel CCDs are in the substrate at the surface. Each CCD includes a channel region and a plurality of conductive gates extending across and insulated from the channel region. The conductive gates extend laterally across the channel regions of all of the CCDs and divide the channel regions into a plurality of phases and pixels. A drain region of the opposite conductivity type is in the substrate at the surface and extends along the channel region of at least one of the CCDs. A simply connected (rectangular) region of the plurality of spaced, parallel CCDs is photoactive. The CCDs outside this photoactive region are typically covered with metal or some other optically opaque material.

Abstract: A GCA+ADC chip 23 on a main circuit board 20 is supplied with an image signal from a CCD circuit board 1 via an input terminal 21 connected to a line 16. Concurrently, the GCA+ADC chip 23 is supplied with a specified DC reference signal REF 13 from the CCD circuit board 1 via an input terminal 22 connected to the other line 17. An internal operation subtracts the DC reference signal REF from the image signal. Drivers 9 and 10 are provided with the same characteristics. If an interfering noise is picked up during transmission, these signals carry the same contents on respective transmission. This interfering noise is canceled during the subtraction inside the GCA+ADC chip 23.

Abstract: The present invention is a black clamp circuit for an electronic imager having black reference pixels. The circuit includes an average value circuit determining an average of a number of the black reference pixels, a correction circuit determining the black level correction from the average, and a modifier circuit modifying image pixels with the black level. The average value is used in a real time feedback loop that removes offset errors in the signal processing chain and establishes a corrected black level in output image data. The feedback can be either digital or analog. The correction circuit can include a comparator that allows a hysteresis in the feedback to avoid hunting as well as multiple levels of feedback based on several thresholds. The corrected black level can also be controlled by a digital transfer function. The black clamp circuit can be used for a series of images, an image frame and an image line.

Abstract: The output voltage of a pixel is held as a reference signal output voltage in a reference signal holding capacitor connected to a positive input terminal of a second subtractor by lowering the potential of a reset voltage to that of a calibration voltage and by activating a reset pulse and a reference-signal-calibrating pulse. Then, the reference signal output voltage is output from the second subtractor. And a corrected reference signal output voltage, obtained by subtracting the reference signal output voltage from a no signal output voltage, is held in a corrected reference signal holding capacitor. Moreover, a divider divides a corrected original signal output voltage, which is held in a corrected original signal holding capacitor, by the corrected reference signal output voltage, which is held in the corrected reference signal holding capacitor.

Abstract: The present invention is a method of image data processing that includes determining whether the image data indicates photodiode saturation, and removing contouring from the image data caused by the saturation. The contour artifact removal is accomplished by adding a random number to adjusted photodiode data from an extended range imager when the data from the imager indicates that the photodiode has been saturated. The adjusted photodiode data is a sum of photodiode data and spillover rate adjusted diffusion data.

Abstract: An image processing apparatus for a charge coupled device including analog front end circuitry having optical black and offset correction, whereby the an offset and optical black correction circuit has a digitally programmable bandwidth is disclosed herein. The image processing apparatus includes a sampling circuit to sample the incoming optical black signal output from a CCD. The sampled signal is filtered through an analog-to-digital converter for processing by a digital detector circuit which detects the average optical black level of the sampled signal. The sum of the channel offset and optical black level present at the output of the digital detector circuit as a digital error signal is averaged for a given number of lines and optical black cells per line by a digital averager included within the digital detector circuit. Moreover, calibration logic digitally calibrates the channel to obtain a user programmed ADC output which corresponds to that average.

Abstract: Image enhancement is automatically achieved by calibrating the reference voltage and gain of a differential amplifier and the integration interval so as to provide an input to a differential analog to digital converter (ADC) that utilizes the full dynamic range of the ADC. When used with a CMOS array, the imaging logic can be fabricated on a single chip with the array using combinational logic for fast, inexpensive calibration. Another advantageous feature is the ability to expand a desired portion of the luminance spectrum of the image in order to increase the digital resolution of the resulting image for that portion of the spectrum of interest.

Abstract: An improved offset correction circuit for an image digitizing system having a correlated double sample and hold circuit, a programmable gain amplifier and an analog-to-digital converter. The output of the analog-to-digital converter is provided to a dual offset correction circuit. The dual offset correction circuit provides both first and second correction values as feedback signals. In one embodiment, the first correction value is a coarse correction which is applied prior to amplification by the programmable gain amplifier. The second correction value is a fine correction offset which is applied as feedback after the programmable gain amplifier.

Abstract: The reduced signal-to-noise ratio of colored pixels that results from a lower conversion efficiency is eliminated by utilizing a programmable gain amplifier which individually applies a gain to the output of each colored pixel so that the maximum signal level of each colored pixel is matched to the maximum input range of an A/D converter.

Abstract: An object of the present invention is to provide an imaging device which can reliably correct dark current components that locally occur in an imaging sensor, such as those caused by an FDA. The imaging device includes: a storage unit which pre-stores information representing a relation between one of dark current components and an output signal of an optical black pixel arranged in a predetermined optical black area on an imaging sensor, the dark current components being superimposed on pixel signals of effective pixels, respectively, arranged in a predetermined effective pixel area on the imaging sensor; a dark current obtaining unit which obtains dark current components based on both the information stored in the storage unit and output signal of the optical black pixel; and a correcting unit which corrects the dark current components obtained by the dark current obtaining unit according to the pixel signals.

Abstract: A number of different elements are added together in a staggered way to avoid the total loss of resolution caused by the binning process. The circuit for doing this includes a variable gain. In a second circuit for carrying this out, to fixed pattern noise reduction circuits are used.

Abstract: An image pickup apparatus comprising: a plurality of pixels each with a photodiode, a logarithmic converter including a logarithmic-converting MOS transistor for converting an output of the photodiode into an electric signal proportional to a logarithmic value of an amount of incident light on the photodiode, and an integration circuit for accumulating an output from the logarithmic converter; a voltage controller for control of a voltage to be applied to the transistor; and an output circuit for receiving signals from the pixels and outputting processed signals. The voltage controller realizes a moving object extraction image pickup state in which an image pickup signal is generated for displaying at least a part of the moving object existing in an image picked-up region at a density different from that of a static background part.

Abstract: A method and apparatus for excess signal compensation in an imaging system is described. In one particular embodiment, the invention provides for non-linear background, offset (due to time dependent dark current) and/or lag (including constant, linear and non-linear terms, due to image persistence) corrections of large area, flat panel imaging sensors.