Abstract: A system includes a microphone, a controller, and a speaker. The microphone is configured to detect noise generated by a functional hardware component due to user interaction with the component. The controller is configured to identify the component from the noise and obtain a noise cancelling signal pre-associated with identification of the component. The speaker is configured to output a noise cancelling sound based on the noise cancelling signal whereby the noise is attenuated.

Abstract: An image processing method includes: (a) generating coefficients corresponding to pixels of a reduced image; (b) generating coefficients corresponding to pixels of an original image from the coefficients corresponding to the pixels of the reduced image, to expand the coefficients corresponding to the pixels of the reduced image to the coefficients corresponding to the pixels of the original image; and (c) multiplying pixel values by coefficients to correct the original image, wherein in step (b), the coefficients corresponding to the pixels of the original image are generated such that a spatial change of the coefficients corresponding to the pixels of the original image is caused according to a boundary between a bright portion and a dark portion, the spatial change occurring mainly on a dark side of the boundary.

Abstract: In an image sensor, a photo detector circuit applies a photo current to a capacitive node during a photo detection time interval. A front-end circuit comprises an input transistor having a control node that is coupled to the capacitive node. A switchable biasing arrangement puts the input transistor in a disabled state during the photo detection time interval. The input transistor is put in an enabled state after the photo detection time interval. This then causes the front-end circuit to provide an output signal that is representative of a voltage on the capacitive node after the photo detection time interval.

Abstract: This image processing device operates by identifying a region that is in a similar image and has a pattern which is the same as a pattern appearing in a section of a reference image, and repeating an operation several times and the section and the region are superposed to generate a reduced-noise fragment, after which the reduced-noise fragments obtained for all of the regions of the reference image are combined to generate a reduced-noise image. When such an operation actually is attempted with an image processing device the regions corresponding to the sections in the reference image cannot be found from the similar image. Therefore, with the present invention the reduced-noise fragments are generated by performing spatial processing on the sections. Thus, reduced-noise fragments can be obtained reliably for all of the regions of the reference image, and noise can be removed from the reference image more reliably.

Abstract: One embodiment describes an electronic display. The electronic display includes display driver circuitry that displays at least a first image frame and a second image frame on the electronic device using a first display pixel and a second display pixel. The electronic display also includes touch sensing circuitry that detects user interaction with the electronic display. A timing controller of the electronic display determines at least a first insertion time for a first intra-frame pause for the first image frame and a second insertion time for a second intra-frame pause for the second image frame. The first and second intra-frame pauses are periods where the display driver circuitry is pauses rendering of image data to allow the touch sensing circuitry to detect user interaction. The insertion times for the first and second intra-frame pauses are varied from one another.

Abstract: Edge enhancement of a digital image can include using at least two signal processing paths to adjust a display-formatted pixel value to enhance the appearance of edges in displayed image data. A digital image can be filtered by producing an edge enhancement factor, ?, per pixel from at least one look up table (LUT). Digital image data can also be adjusted using at least two signal processing paths, where the image data is adjusted if a pixel value and its neighboring pixel values are all within a smoothing range or where the pixel delta value is outside of a bad pixel range and its neighboring pixel delta values are all within the bad pixel range. In such cases, the image data can be adjusted by replacing the pixel value with an average or median value of the neighboring pixels.

Abstract: An image capturing apparatus comprises an image capturing unit that includes an image sensor that has an effective pixel region and a reference pixel region which outputs a reference signal for correcting an output signal of the effective pixel region. In a case where a predetermined condition is satisfied, a reduction unit reduces a data amount of reference pixel region data that corresponds to the reference pixel region in an image data obtained by the image capturing unit. A recording unit records the image data after the processing performed by the reduction unit.

Abstract: A multi-scale detail representation of an image is computed as a weighted sum of translation difference images. A denoising operator is applied to the translation difference images so that translation differences are modified as a function of an estimated local signal-to-noise ratio and at least one denoised center difference image at a specific scale is computed by combining denoised translation difference images at scale s or a finer scale. A denoised image is computed by applying a reconstruction algorithm to the denoised center difference images.

Abstract: An image enhancement method and an image processing apparatus thereof are provided. The image enhancement method is adapted to the image processing apparatus and includes the following steps. An input image is obtained, wherein the input image has a plurality of intensity components. The input image is corrected according to a gamma curve. The sharpness of the corrected input image is enhanced based on an edge detection operator and a weight value. An output image suitable for a display panel is obtained based on the enhanced input image.

Abstract: A solid-state imaging device includes a photoelectric conversion section configured to generate photocharges and a transfer gate that transfers the photocharges to a semiconductor region. A method for driving a unit pixel includes a step of accumulating photocharges in a photoelectric conversion section and a step of accumulating the photocharges in a semiconductor region. A method of forming a solid-state imaging device includes implanting ions into a well layer through an opening in a mask, implanting additional ions into the well layer through an opening in another mask, and implanting other ions into the well layer through an opening in yet another mask. An electronic device includes the solid-state imaging device.

Abstract: To provide an image pickup apparatus that can increase capacitance value of an input node in a connection state without decreasing amplification transistor gain when capacitance is in a non-connection state. In an image pickup apparatus according to an aspect of the present disclosure, a gate electrode of an amplification transistor is arranged on a main surface of the semiconductor substrate, a third semiconductor region having a second conductivity type is arranged in a lower part of the gate electrode, and an added impurity concentration of impurity having the second conductivity type on a PN junction surface of a capacitance is higher than a highest value of an added impurity concentration having the second conductivity type in a region from the main surface up to a depth at which a source and a drain of the amplification transistor are arranged in the third semiconductor region.

Abstract: An image processing device capable of easily reducing stripe pattern noise caused by e.g. variation in power supply voltage when addition processing is performed for adding a plurality of images obtained by photographing. An image processing device synthesizes a plurality of images continuously obtained from an image pickup device. In a case where noise is added from a noise source to each of the images when thy are continuously read out from the image pickup device, timing of driving the image pickup device is controlled, such that a phase of noise added from the noise source during read-out of an image and a phase of noise added from the noise source to an image read out immediately before the image being currently read out have a predetermined relationship.

Abstract: Embodiments are directed to systems and methods to intelligently reduce the dynamic range of a signal. Using a histogram analysis of the signal, significant and insignificant portions of the original dynamic range can be identified. Compaction can then be focused on the insignificant portions of the dynamic range, resulting in significant dynamic range reduction with less signal loss. By compacting the little used portions of the original signal, the dynamic range of the rest of the signal can be largely maintained which results in little loss to signal fidelity, and thus mitigates saturation, quantization, signal mutual suppression, and other issues observed in prior art methods.

Abstract: An image processing apparatus of the present invention includes: a structure index calculation unit that calculates a structure index that is an index of magnitude of variation of a pixel value in a predetermined range around a target pixel of an input image, with respect to each target pixel; a high frequency component extraction unit that extracts a high frequency structure index that is a high frequency component of the structure index; a smoothing unit that calculates a smoothed structure index obtained by smoothing the structure index, with respect to the each target pixel; a flatness index calculation unit that calculates a synthesis index obtained by synthesizing the smoothed structure index and the high frequency structure index, as a flatness index of the target pixel; and a noise reduction unit that performs a noise reduction process of the target pixel in accordance with the flatness index.

Abstract: A focus detection unit detects a defocus value, and a correction value for shifting an in-focus position based on the defocus value is obtained by a first method or by a second method. The correction value obtained by the second method is converted to a correction value of the first method by changing units, and the correction value obtained by the first method or the converted correction value is stored in a storage unit. A control unit controls driving of a focus lens to a lens position based on a value obtained by correcting the defocus value by the stored correction value. In the second method, a user selects one of a plurality of images obtained by driving the focus lens, and the correction value is calculated based on the defocus value of the selected image.

Abstract: Embodiments for a depth sensing camera with a wide field of view are disclosed. In one example, a depth sensing camera comprises an illumination light projection subsystem, an image detection subsystem configured to acquire image data having a wide angle field of view, a logic subsystem configured to execute instructions, and a data-holding subsystem comprising stored instructions executable by the logic subsystem to control projection of illumination light and to determine depth values from image data acquired via the image sensor. The image detection subsystem comprises an image sensor and one or more lenses.

Abstract: An imaging device 10 according to an aspect of the present invention includes: an image generation section 100 that generates a moving image; a filter acquisition section 105 that acquires a restoration filter corresponding to a transfer function for the point distribution of an optical system; an aperture value detection section 110 that detects an aperture value of the optical system; a restoration processing determination section 115 that determines whether or not the aperture value detected by the aperture value detection section 110 is equal to or greater than a small-aperture-blurring reference aperture value; and a restoration processing execution section 120 that executes the restoration processing on the moving image through the restoration filter, in case where the restoration processing determination section 115 determines that the aperture value detected by the aperture value detection section 110 is equal to or greater than the small-aperture-blurring reference aperture value.

Abstract: The image processing device includes an imaging unit configured to capture a plurality of pupil-divided images obtained from light fluxes passing through different pupil regions of an imaging optical system, and a control unit configured to select images to be used for image processing from the pupil-divided images captured by the imaging unit, according to the position of the imaging area in the imaging unit.

Abstract: A computer system with one or more processors and memory performs a breadth-first-search for an analysis of a digital circuit that includes a plurality of components. The computer system identifies two or more N generation components, initiates processing of the two or more N generation components, and subsequent to initiating the processing of the two or more N generation components, receives results of processing a subset, less than all, of the two or more N generation components. Prior to receiving results of processing all of the N generation components, the computer system identifies one or more N+1 generation components, and initiates processing of the one or more identified N+1 generation components. Subsequently, the computer system receives results of processing at least a subset of the one or more identified N+1 generation components.

Abstract: An image capturing apparatus includes an image sensor having a plurality of pixels and being capable of outputting a plurality of image signals read out using different methods for individually reading out the signals of the plurality of pixels and correction signals for correcting the plurality of image signals, a processing unit for processing the correction signals so as to handle the reading methods for the plurality of image signals, and a correction unit for correcting the plurality of image signals using the correction signals processed by the processing unit.

Abstract: The present invention comprises a system for and method of frequency prefiltering comprising a camera shutter capable of continuously variable illumination during a single exposure of the sensor. The shutter comprises a continuously variable exposure effector which in disposed in an image path, either in front of a lens or between a lens and a sensor. The system for frequency prefiltering further comprises a synchronization cable that synchronizes a drive system with a sensor or with film. The shutter further comprises a postfilter. The postfilter comprises a digital finite impulse response convolutional filter.

Abstract: The disclosure relates to a multi-camera imaging system, and a compensation method for image reconstruction. The main components of the multi-camera imaging system are an image capturing module having a multi-lens module and a multi-sensor module, and a distance adjustment unit automatically adjusting the distance between the multi-lens and multi-sensor modules. Note that the distance adjustment unit conducts compensation performed on the change of the system's focal length caused by temperature in the system. The multi-camera imaging system further includes a position-sensing module which is used to sense a displacement or change of the distance made by the distance adjustment unit. A set of image reconstruction parameters corresponding to the displacement or the change of distance is then provided.

Abstract: Various implementations address high dynamic range (“HDR”) images. In one particular implementation, a low dynamic range (“LDR”) image is generated from an HDR image, and information is generated allowing the HDR image to be reconstructed from the LDR image. The LDR image and the information are encoded. In another implementation, a signal or signal structure includes an LDR section including the encoded LDR image, and an information section including the encoded information. In another implementation, the encoded LDR image and the encoded information are both decoded. The HDR image is then reconstructed based on the decoded LDR image and the decoded information.

Abstract: Systems and methods are provided for generating high-dynamic range images. In particular, a signal-to-noise (SNR) ratio objective associated with an imaging platform configured to capture one or more images of a region of interest can be determined. The SNR objective can specify a desired signal-to-noise ratio behavior as a function of a brightness of the region of interest. An exposure profile associated with the imaging platform can then be determined based at least in part on the SNR objective. Data indicative of a plurality of image frames, each depicting at least a portion of the region of interest, can then be obtained. The plurality of image frames being captured by the imaging platform in accordance with the exposure profile.

Abstract: An image sensor includes a first pixel that is in an active pixel region, a second pixel that is in a dummy region adjacent the active pixel region, and a first deep trench isolation (DTI) formed between the first pixel and the second pixel.

Abstract: Disclosed is an image sensor that includes a pixel array including a plurality of unit pixels in a matrix having rows and columns, a binning sampling unit configured to (i) amplify with different gains signals from unit pixels selected from the unit pixels in each of the columns, and (ii) output a binning sampling signal according to an average of the amplified signals, and an analog-to-digital converter configured to convert the binning sampling signal to a digital signal.

Abstract: An image sensor may have an array of pixels and readout circuitry. The array may include image pixels that generate signals in response to image light and reference pixels that generate signals in response to electrical noise. The readout circuitry may obtain first pixel values from the image pixels and may obtain second pixel values from the reference pixels. The readout circuitry may generate an extended precision pixel value based on the second pixel values that have an extended bit width relative to the each of the second pixel values. The readout circuitry may generate multiple dithered correction values by adding randomized sequences of least significant bits to the extended precision pixel value. The readout circuitry may mitigate visible quantization error and noise such as row-correlated and column-correlated noise in the final image by subtracting the dithered correction values from corresponding first pixel values.

Abstract: A solid-state image pickup device includes an optoelectronic conversion unit, a first optical signal accumulation unit, a second optical signal accumulation unit, and a combining unit, in which the first optical signal accumulation unit accumulates a first optical signal obtained by the optoelectronic conversion by the optoelectronic conversion unit in a first period, the second optical signal accumulation unit accumulates a second optical signal obtained by the optoelectronic conversion by the optoelectronic conversion unit in a second period, the second period being shorter than the first period, and the combining unit combines the second optical signal with the first optical signal when a noise in the first optical signal is equal to or larger than a noise in the second optical signal.

Abstract: An image processing apparatus executes image processing on image data obtained by forming an image on an image pickup element. The image processing apparatus includes an obtaining unit configured to obtain a pixel in the image data corresponding to a specific position in the image pickup element as a specific pixel, a determination unit configured to determine a target region including a target pixel and a reference region including a reference pixel which are used for determining a degree of similarity between the target pixel and the reference pixel in accordance with the specific pixel obtained by the obtaining unit, and a calculation unit configured to calculate a degree of similarity between the target pixel and the reference pixel by comparing the target region and the reference region determined by the determination unit.

Abstract: Computer processor hardware receives settings information for a first image. The first image includes a set of multiple display elements. The computer processor hardware receives motion compensation information for a given display element in a second image to be created based at least in part on the first image. The motion compensation information indicates a coordinate location within a particular display element in the first image to which the given display element pertains. The computer processor hardware utilizes the coordinate location as a basis from which to select a grouping of multiple display elements in the first image. The computer processor hardware then generates a setting for the given display element in the second image based on settings of the multiple display elements in the grouping.

Abstract: An image capturing apparatus includes: an image capturing element in which a plurality of pixels are formed and arranged and phase difference pixels are formed within an effective pixel region; a photographing lens; and a control unit which analyzes a captured image signal by the image capturing element, obtains a phase difference amount from detection signals of two of the phase difference pixels that make a pair, and performs a focusing control of the photographing lens, in which the control unit calculates, as a sensitivity ratio, a ratio of an integration value of light receiving sensitivity of the phase difference pixel within a range of an incident angle of the photographing lens, and an integration value of light receiving sensitivity of a pixel other than the phase difference pixel, and corrects a deviation in light receiving sensitivity between the two phase difference pixels.

Abstract: An image conversion apparatus extracts from among pixel rows parallel to an object pixel row, a first pixel row overlapping an aperture shape; and further extracts a second pixel row having the number of pixels successively overlapping the aperture shape equal to or greater than that of the first pixel row. The image conversion apparatus calculates a value of a second pixel in the case of converting an original image, by referring to a storage unit that stores a value of a first pixel in the case of converting the original image. For example, the image conversion apparatus defines an average of the value of the first pixel in the case of converting the original image, a value of a diffusion source pixel (IN[5][2]), and a diffusion source pixel (IN[5][3]) as the value of the second pixel in the case of converting the original image.

Abstract: A method and system for reconstructing an image of a scene comprises configuring a digital light modulator according to a spatially varying pattern. Light energy associated with the scene and incident on the spatially varying pattern is collected and optically focused on the photodetectors. Data indicative of the intensity of the focused light energy from each of said at least two photodetectors is collected. Data from the photodetectors is then combined to reconstruct an image of the scene.

Abstract: Systems, methods, and apparatuses that may be employed to reduce noise in an electronic circuit are described. Systems are provided that include a circuit, wherein the circuit is configured to provide an active reset technique and an active column sensor readout technique. Methods for reducing circuit noise are also provided. The methods include providing a circuit configured to perform an active reset technique and an active column sensor readout technique. The methods further provide that the active reset technique and the active column sensor readout technique are both performed by the circuit. An imaging apparatus is provided that includes an array of photo-sensitive pixels, wherein each of the pixels can include a circuit configured to provide an active reset technique and an active column sensor readout technique. The active reset technique and the active column sensor readout technique are executable on the circuit.

Abstract: To provide an apparatus that generates an RGB pattern data from an image pickup signal by an image pickup element having an RGBW pattern and a method. An edge detection unit analyzes an output signal of the image pickup signal of the RGBW pattern to obtain edge information corresponding to the respective pixels, and a texture detection unit generates texture information. Furthermore, a parameter calculation unit executes an interpolation processing in which an applied pixel position is changed in accordance with an edge direction of a transform target pixel to generate parameters equivalent to an interpolation pixel value.

Abstract: Technologies that enable correcting for the non-linear relationship between scene irradiance and digital pixel intensity values of an image of the scene produced by a camera. Imaging noise is used as a signal from which a corrective function is derived. Noise distributions from the image are evaluated to determine the radiometric response function of the camera, from which an inverse response function is computed and used for calibration.

Abstract: A first image taken by a first camera device in the plurality of camera devices and first imaging environment information indicating a first imaging environment of the first camera device at a time of taking the first image is acquired. By using a parameter table that manages imaging environment information indicating an imaging environment at a time of taking an image previously by a camera device and a recognition control parameter indicating a detector corresponding to an imaging environment, a first recognition control parameter indicating a first detector corresponding to third imaging environment that is identical or similar to the first imaging environment indicated by the first imaging environment information acquired from the first camera device is selected from the recognition control parameters. The first image acquired from the first camera device is recognized by using the first detector indicated by the selected first recognition control parameter.

Abstract: The present invention provides a driving method for an image pickup apparatus that appropriately performs both readout of a signal of a reference pixel and mixing of mutual signals output by a plurality of effective pixels, and the present invention also provides an image pickup apparatus and an image pickup system.

Abstract: An image sensor configured to readout an arbitrary number of rows in parallel is described, comprising a rolling global shutter pixel array which can be operated as a true global shutter. Shielding structures may be formed in the pixel array to minimize signal coupling between adjacent pixels when multiple rows are simultaneously reset and read out. A plurality of column select lines may be formed in a given pixel pitch, and the image sensor may utilize read out components and circuitry associated with conventional readout circuits to be used in simultaneously reading out a two-dimensional region of the image sensor. The image sensor may be configured to use charge binning between rows that are reset and read out in parallel to improve power consumption. The image sensor may include redundant output stages with routing circuitry that improves image sensor yield by compensating for yield loss in the output stage.

Abstract: There is provided a signal processor including a phase difference detection part configured to acquire a pixel value of one light-shielding pixel having a part of a light-receiving region shielded therein and pixel values of a peripheral pixel row of the light-shielding pixel in a light shielding direction. A corrected pixel value obtained by subjecting the pixel value of the light-shielding pixel to a reduced sensitivity correction is compared with the pixel values of the peripheral pixel row to detect a phase difference of the light-shielding pixel.

Abstract: Mechanisms for spatially isolating a region of interest (ROI) in a scene are disclosed. A first sensor generates sensor data that quantifies energy received from a scene within a field of view (FOV) of the first sensor to generate a real-time FOV full motion video. A processor analyzes the sensor data to identify a first ROI during a wait period of a frame period of the first sensor. A first subset of micromirrors in a micromirror array that is directed toward the scene is identified. The first subset of micromirrors receives energy from the first ROI. At least one micromirror in the first subset is controlled to move from a primary position of the at least one micromirror to a first tilt position of the at least one micromirror to reflect the energy from the first ROI toward a second sensor, the first ROI being spatially isolated from the real-time FOV full motion video.

Abstract: A pixel has a photodiode configured to be sensitive to light. The pixel is arranged to use back side illumination. The pixel has at least one sample and hold capacitor which is arranged on the side of the photodiode remote from a side on which light impinges. The capacitor overlies at least part of the photodiode.

Abstract: The present invention provides an image denoising method and an image denoising apparatus. The image denoising method includes performing preliminary denoising processing to an acquired image to be processed, so as to obtain a preliminarily denoised image; calculating a residual quantity corresponding to a central pixel of each unit area in the image to be processed according to numerical values of specific energy parameters to which the image to be processed and the preliminarily denoised image correspond, respectively; and using the residual quantity to calculate a weight matrix corresponding to each unit area, and performing non-local mean value calculation to the image to be processed according to the weight matrix, so as to realize the denoising processing of the image to be processed. The image denoising method is able to denoise effectively, and make a denoised image more visually natural.

Abstract: A solid-state imaging device includes: pixels arrayed two-dimensionally; pixel common circuits arrayed in a matrix, each shared by adjacent pixels of a certain number among the pixels; column common circuits, each provided for one of columns of the pixel common circuits, and shared by pixel common circuits belonging to a same column; column signal lines each provided for one of the columns of the pixel common circuits; and reset signal lines each provided for one of the columns of the pixel common circuits, in which an electric signal from each of the pixels is detected by a corresponding one of the pixel common circuits and read by a corresponding one of the column common circuits, and the electric signal detected by the corresponding one of the pixel common circuits is reset by a feedback path including one column signal line, one column common circuit, and one reset signal lines.

Abstract: An imaging apparatus includes an image sensor, an AD conversion unit, a clamp processing unit, and a video signal correction unit. The clamp processing unit is configured to clamp to a black level, an image signal of an effective pixel region or an optical-black region of the image sensor after having been digitally converted by the AD conversion unit, by evaluating a difference from a signal of the optical-black region. The video signal correction unit is configured to calculate signal information of a part or whole of the optical-black region of an image signal of the image sensor; and, independently for each color of the video signal, to calculate correction amount of a video signal using the signal information, and to carry out correction by subtracting calculated correction amount from the image signal before clamping operation performed by the clamp processing unit.

Abstract: An imaging apparatus includes an image sensor configured to convert an incident electromagnetic wave into current; a current/voltage conversion circuit that is configured to convert the current input from the image sensor into voltage and includes an operational amplifier configured to output voltage corresponding to the current input from the image sensor; and a sampling circuit that is configured to sample output of the operation amplifier and is provided between input/output terminals of the operational amplifier.

Abstract: An image sensor includes a sampling circuit, which is responsive to ramp and input signals provided by a pixel array. The sampling circuit is configured to perform a correlated double sampling (CDS) operation on a reset component of the input signal and an image component of the input signal. A reset circuit is also provided, which is configured to reset an output signal generated by the sampling circuit to a first level in response to a reset control signal. This reset control signal can be active during at least one of a first reset interval and a second reset interval. The first reset interval precedes a first comparison interval during which a first comparison operation is performed on the ramp signal and the reset component. The second reset interval precedes a second comparison interval during which a second comparison operation is performed on the ramp signal and the image component.

Abstract: The present invention provides an image denoising method and an image denoising apparatus. The image denoising method includes performing preliminary denoising processing to an acquired image to be processed, so as to obtain a preliminarily denoised image; calculating a residual quantity corresponding to a central pixel of each unit area in the image to be processed according to numerical values of specific energy parameters to which the image to be processed and the preliminarily denoised image correspond, respectively; and using the residual quantity to calculate a weight matrix corresponding to each unit area, and performing non-local mean value calculation to the image to be processed according to the weight matrix, so as to realize the denoising processing of the image to be processed. The image denoising method is able to denoise effectively, and make a denoised image more visually natural.

Abstract: Removal of the effects of dust or other impurities on image data is described. In one example, a model of artifact formation from sensor dust is determined. From the model of artifact formation, contextual information in the image and a color consistency constraint may be applied on the dust to remove the dust artifacts. Artifacts may also be removed from multiple images from the same or different cameras or camera settings.

Abstract: A method to read out pixels includes reading a first pixel by resetting a first photodetector, integrating the first photodetector after resetting the first photodetector, resetting a first floating diffusion node coupled to the first photodetector and a second floating diffusion node coupled to a second photodetector, transferring charge from the first photodetector to the first floating diffusion node, comparing a first signal at the first floating diffusion node and a second signal at the second floating diffusion node and generating a first signal to latch a first counter value when the first signal is less than the second signal, incrementing the first signal and decrementing the second signal, and comparing the first signal and the second signal and generating a second signal to latch a second counter value when the first signal is greater than the second signal, wherein the difference between the second counter value and the first counter value indicates a first pixel level.