Abstract: A gain control circuit includes a light detector for generating an amount of current based on received light and a first switch for controlling the amount of current from the light detector delivered to a node. The gain control circuit also includes a charge storage element for providing an amount of capacitance to the node and a second switch for controlling the amount of capacitance provided to the node. The gain control circuit further includes an output interface for delivering an output signal based on the amount of current and the amount of capacitance at the node. The light detector may include multiple photodiodes, and the first switch may include a pair of NMOS switching transistors coupled to at least one photodiode. Also, the charge storage element may include multiple capacitors, and the second switch may include a PMOS transistor and an NMOS transistor coupled to each capacitor.

Abstract: In an imaging device having an all-pixel read mode for reading signals from all pixels and a pixel downsampling read mode for reading signals by appropriately discarding pixels, adjacent ones of pixels use a floating diffusion capacitance, an amplifying transistor, a reset switch and a selection switch in common. In the pixel downsampling read mode, not only a primary capacitance but also a photodiode in each pixel to be discarded are used as capacitances for storing signal charges transferred from transfer switches. This makes it possible to lower the gate voltage of the amplifying transistor as compared with the case of using only the primary capacitance as a capacitance for storing signal charges transferred from a transfer switch to reduce the sensitivity of the pixels, thereby reducing the occurrence of flicker.

Abstract: A flicker is corrected with consideration given to the influence of noises. The present invention provides a flicker correction method in which a flicker is corrected by subtracting a flicker correction signal from an image signal, the method including the steps of removing noise from the flicker-corrected image signal by passing the latter through a low-pass filter, generating a correction error signal from the noise-removed, flicker-corrected image signal and the image signal not yet flicker-corrected, removing the image signal not yet flicker-corrected by passing the latter through a low-pass filter, and generating a flicker correction signal from the noise-removed image signal and correction error signal.

Abstract: An image processing apparatus includes: an integrating unit integrating an input image signal over a time interval equal to one horizontal period or longer; a normalizing unit normalizing an integrated value obtained by the integrating unit, or a difference value in the integrated value between adjacent fields or frames; an extracting unit extracting a spectrum of the normalized integrated value or difference value; an estimating unit estimating a flicker component on a field-by-field basis or frame-by-frame basis from the extracted spectrum; a detecting unit detecting a deviation of the latest flicker component, from the estimated latest flicker component and one or more flicker components estimated in the past; a correcting unit correcting the latest flicker component on the basis of the detected deviation of the flicker component; and a computing unit computing a corrected flicker component and the input image signal so as to cancel out the corrected flicker component.

Abstract: Disclosed is a method for integrating an image sensor capable of removing a flicker noise without causing any burdens on a hardware due to setting up additional logics. The method for integrating an exposure time of an image sensor employing a line scan method, including the steps of: performing an integration to a first line when an integer multiple of a light source frequency is different from an integration time; and performing an integration to a second line at a phase substantially equal to a phase in which the integration to the first line is started.

Abstract: In one embodiment, a method for controlling artifacts in an image due to a presence of flicker in ambient light is provided. The method comprises determining a power frequency for the ambient light; determining a magnitude and phase of flicker fluctuation in the image due to the flicker; and adjusting the image for the flicker fluctuation based on the power frequency, magnitude, and phase.

Abstract: An image processing apparatus includes a change unit configured to change a driving state of an image sensor for capturing an image signal in response to an operation for changing the driving state of the image sensor, and a flicker correction unit configured to correct an image signal based on a flicker component detected from image signals of a frame captured a predetermined number of frames before the frame of the image signal to be corrected, wherein the flicker correction unit is configured to change the predetermined number when the driving state of the image sensor is changed by the change unit.

Abstract: To automatically detect and correct flickers in a video capture device, a frame number generator receives a plurality of frames and generates frame numbers. A storage device stores brightness values of partial pixels of a frame numbered 1. An extractor extracts brightness values of partial pixels of a frame numbered N. A difference summation device computes differences of the brightness values of the partial pixels of the frames numbered 1 and numbered N and sums up the differences to generate a brightness difference summation signal. A flicker detector detects a banding value in the brightness difference summation signal. A flicker corrector uses the banding value and the frame numbers to find a fixed frequency flicker effect in the frames, and generates a flicker correction signal when the fixed frequency flicker effect in the frames is found.

Abstract: A system and method for detecting flicker in a digital image. The system and method detects flicker by performing a frame-to-frame comparison of image data. The frame-to-frame comparison of image data is based on dividing each image into multiple columns, and performing a weighted sum of the pixel luminance in each column using a pattern of alternating sign weights. The weighted sum of luminance for each column in a first frame is compared to the weighted sum of luminance for that column in a second frame to determine if there is a simultaneous luminance variation in those columns. For example, if the difference between weighted sums of luminance between frames exceeds a threshold value in a predetermined number of columns then there is a simultaneous luminance variation in those columns, and a horizontal pattern of flicker has been detected in the image data.

Abstract: An image pickup apparatus capable of accurately detecting a flicker in a short time period without regard to a state of object and a photography scene. A signal processing circuit reads out an n-th line of an image subjected to collective reset/collective transfer readout, reads out an n-th line of an image subjected to rolling readout, and subtracts an output of a pixel section of a particular column of the n-th line of the image subjected to the rolling readout from an output of a corresponding pixel section of the image subjected to the collective reset/collective transfer readout. The signal processing circuit determines that a flicker is generated, if there is a differential value not less than a predetermined threshold value between each pair of outputs from the pixel sections of the same line and if there is a periodicity in an image vertical direction.

Abstract: The integration time for an imager is adjusted to be an integer multiple of the light intensity received by the imager to reduce or eliminate flickering.

Abstract: Disclosed is a method for integrating an image sensor capable of removing a flicker noise without causing any burdens on a hardware due to setting up additional logics. The method for integrating an exposure time of an image sensor employing a line scan method, including the steps of: performing an integration to a first line when an integer multiple of a light source frequency is different from an integration time; and performing an integration to a second line at a phase substantially equal to a phase in which the integration to the first line is started.

Abstract: It is determined whether or not flicker has occurred in an image signal obtained on the basis of an output signal of an image pickup element. If it is determined that flicker has occurred, a flicker correction method is selected according to a gain value set in the image signal.

Abstract: An image sensor has an imaging surface irradiated with an optical image of an object scene, and repeatedly generates an object scene image. A CPU repeatedly determines whether or not a specific variation exceeding a reference is generated in the object scene captured by the image sensor, in parallel with a generating process of the object scene image by the image sensor. When a determination result is updated from a negative result to an affirmative result, the CPU waits for an elapse of a designated period, then, determines presence or absence of a generation of a flicker, and executes a flicker countermeasure process, as needed.

Abstract: A method for detecting the presence of flicker in video images includes obtaining luminance data from sampled image fields and analyzing the luminance data to obtain a digital number characterizing the brightness of the luminance data. Frequency analysis is performed on a time-series of digital numbers collected over multiple sampled image fields to provide a signal indicative of the spectral energy at a flicker frequency band and a signal indicative of the spectral energy at a non-flicker frequency band. A ratio of the two spectral energy signals is computed as the flicker detect indicator. Multiple flicker detect indicators are accumulated to generate a flicker present signal. In one embodiment, the flicker detect indicator is accumulated only when the ratio has a value greater than a first threshold and the flicker present signal is asserted only when the number of flicker detect indicator signals accumulated exceeds an entry value.

Abstract: An arithmetic processing section executes an arithmetic process on a flicker correction signal output from a flicker correction signal outputting section and corresponding to the flicker component contained in a video signal of each of specific periods and the video signal of each of the specific periods to form a corrected video signal of the specific period corrected for the flicker component of the specific period for the video signal of each of the specific periods formed as a succession of specific periods and containing a flicker component as supplied from a video signal generating section in response to a correction error signal of each of the specific periods supplied from a correction error detecting section.

Abstract: A computer assisted method identifies characteristics of a flare. A digital image of the flare is obtained, such as by a color digital video camera and a region of interest likely containing the flare is identified. Flare pixels within the region of interest are identified and color information is extracted from such flare pixels.

Abstract: Provided are a flicker correcting device and a flicker correcting method which are capable of reducing the frequency of occurrence of a flicker during detection of the flicker. A nonvolatile memory stores information on a power source frequency of illumination under an image pickup environment. A control unit performs a setting related to flicker correction of an image pickup unit based on the information stored in the nonvolatile memory. A signal processing circuit detects a flicker from image data acquired in the set state. The control unit writes the information on the power source frequency of illumination under the image pickup environment into the nonvolatile memory based on a result of flicker detection by the signal processing circuit.

Abstract: An imaging apparatus reduces flicker occurring under fluorescent lamp illumination in real time and also effectively reduces noise of a captured image generated by low-sensitive pixel areas fixed on an imaging surface. The imaging apparatus obtains a first image signal including no flicker element and a second image signal including a flicker element for each frame, and calculates a gain correction coefficient for eliminating the flicker element in the second image signal based on the first and second image signals, eliminates the flicker element from the second image signal based on the gain correction coefficient, and combines the first and second image signals to generate an image signal from which the flicker element has been eliminated. The imaging apparatus also effectively reduces noise of a captured image generated by low-sensitive pixel areas fixed on an imaging surface by changing the charge accumulation time of pixels depending on each frame.

Abstract: An apparatus such as a digital camera includes an image sensor array adapted to capture a scene into electrical values and a reference detector proximal to the sensor array for detecting illuminant intensities. The reference detector at least partially surrounds the image sensor array. The reference detector is read multiple times during the frame period in which the image sensor array captures a scene to detect illuminant intensities during the same frame period. Using the illuminant intensities, the phase and the amplitude of the flicker of the illuminant are extracted. Using the phase and the amplitude parameters, a flicker correction signal is synthesized. The flicker correction signal is used to correct the captured image data to reduce or eliminate adverse effects of flicker on the captured image.

Abstract: The invention is an image capture device having an image capture element. The device further includes a flicker detection portion which extracts flicker component signals corresponding to periodic changes in brightness in an image capture environment from image signals for each frame supplied by the image capture element, performs correction to remove signals at or below a prescribed reference low-amplitude value, and detects the frequency or the period of the flicker component from the peaks and valleys of the corrected flicker component signal.

Abstract: To reduce flicker appropriately according to illumination condition of an imaging subject, a video camera is provided. The video camera includes an imaging unit for generating a subject image; a superimposing image generator for generating a superimposing image; an image synthesizer for synthesize the subject image and the superimposing image to generate a synthesized image; a video signal generator for generating a video signal from the synthesized image so as to display the synthesized image. The video camera also includes a flicker reduction unit to reduce flicker caused by luminance fluctuation of a light source. The flicker reduction unit has a plurality flicker reduction modes. The mode setting unit makes the superimposing image generator to generate a settings screen as the superimposing image for assisting selection of one of the flicker reduction modes.

Abstract: The present invention is to allow an XY-address scanning-type imaging device such as a CMOS imaging device to detect a fluorescent flicker correctly and accurately and reduce a fluorescent flicker component surely and sufficiently. The RGB primary color signals arising from A/D conversion of the RGB primary color signals obtained from an imaging element are clamped. Subsequently, for the clamped RGB primary color signals, the following processes are executed: correction of the gains of reading-out channels; reduction of fixed pattern noise; correction of the data of defective pixels; noise reduction; lens shading correction; and gain adjustment for exposure adjustment. Thereafter, for the resultant signals, a flicker detection and reduction unit 60 detects and reduces a flicker component.

Abstract: An apparatus for detecting flicker noise disclosed in the present invention comprises an output unit for outputting a standard data for flicker noise judgment using a statistical calculation value for each calculated line based on brightness information of pixels for each line of an object image for flicker noise detection; a flicker line detection unit for detecting flicker lines, namely, lines corresponding to the standard data where the distance between the lines are within a predetermined allowance of a regular interval; and a judgment unit for comparing the number of the detected flicker lines with a standard number for flicker noise judgment to judge if the object image is a flicker noise image. The present invention can realize a method for detecting flicker noise, in which an image obtained with the reduced calculation time and use of a minimum memory has a robust in characteristics of a subject.

Abstract: An image input apparatus. A detection section detects a change cycle of an intensity of an external light inputted to a camera. A timing control section synchronizes the change cycle of the intensity of the external light with a plurality of input timings of the camera by changing a phase difference in order. An evaluation section compares each storage quantity of the external light inputted to the camera at the plurality of input timings synchronized by the timing control section for each phase difference. A selection section selects the phase difference whose difference of the storage quantities of the external light is smallest from all phase difference changed by the timing control section.

Abstract: Provided is a method and apparatus for reducing flickers of an image sensor capable of reducing line flickers due to a complementary metal-oxide-semiconductor (CMOS) sensor. The method includes: estimating a profile of a light source per line on the basis of information on image frames which are continuously input; filtering information of the estimated profile of the light source with a predetermined bandwidth; normalizing the filtered information of the estimated profile of the light source, and extracting a correction gain per line; and selecting the correction gain per line repeated in units of predetermined frames, and applying the correction gain to an input image signal.

Abstract: A novel method and apparatus for controlling operation of a photosensor array in a portable electronic device to reduce flicker resulting from fluorescent light having a periodic intensity. The method comprises selecting a time zone in which the device is to be operated, correlating the time zone with a corresponding frequency of the fluorescent light, and signaling the photosensor array to operate in accordance with a mode optimized to reduce flicker based on the selected time zone.

Abstract: An image sensor has improved functions so as to automatically eliminate a flicker noise. For the purpose, the image sensor includes a pixel array for capturing information about an image provided from the outside and having N pixel rows and M pixel columns for maximizing a feature of reacting to light, wherein M and N are integers, respectively, a flicker noise detective pixel unit containing X pixel rows, which has a form extended from the N pixel rows of the pixel array, and M pixel columns, wherein each pair of X pixel rows has an identical exposure time and X is an even number, and a flicker noise for controlling an exposure point for the flicker noise detective pixel unit and detecting the flicker noise by using outputs of the flicker noise detective pixel unit.

Abstract: Systems, methods and devices related to detecting and transmitting images. Imaging systems and devices, as well as methods of using such that are provided herein include flicker detection and/or correction; and/or built-in self test associated with various analog circuitry in the imaging devices; and/or power reduction ability; and/or pixels with charge evacuation functionality; and/or a parallel to serial conversion unit and associated serial output interface; and/or other advanced functionality.

Abstract: An image pickup apparatus comprises an image pickup unit including a plurality of photoelectric conversion units for picking up an image of an object; and a filter, arranged on the image pickup unit, for reducing a light amount that causes a flicker.

Abstract: Methods for reducing artifacts caused by illuminant flicker are provided. One such method comprises: providing pixel circuits; and operating the pixel circuits in a bi-directional mode during which first information corresponding to a scene is acquired in forward row-sequential order of the pixel circuits and then second information corresponding to the scene is acquired in a reverse row-sequential order of the pixel circuits. Systems also are provided.

Abstract: The present disclosure provides a method for detecting flicker DC voltage offset. The method includes receiving an output signal of an image sensor, the output signal comprising a reference signal and an image signal, and generating a combined signal by combining the image signal with a peak flicker DC voltage signal during a first time period. The method also includes performing an auto zero function in an auto zeroing comparator during the first time period between the reference signal and the combined signal and comparing the reference signal and the image signal with the auto zeroing comparator during a second time period subsequent to the first time period. The method further include storing a first charge corresponding to the image signal during a second time period and storing a second charge corresponding to a current peak flicker DC voltage signal.

Abstract: A flame detecting method is provided. The method comprises steps of capturing a video segment for a object; analyzing if an image of the object is moving; analyzing at least one of a color model and a flickering frequency of the moving object; comparing analyzed results obtained from the analyzing steps to a flame feature; and determining if the object is a flame.

Abstract: An image input apparatus. A detection section detects a change cycle of an intensity of an external light inputted to a camera. A timing control section synchronizes the change cycle of the intensity of the xternal light with a plurality of input timings of the camera by changing a phase difference in order. An evaluation section compares each storage quantity of the external light inputted to the camera at the plurality of input timings synchronized by the timing control section for each phase difference. A selection section selects the phase difference whose difference of the storage quantities of the external light is smallest from all phase difference changed by the timing control section.

Abstract: An image sensing apparatus has a first setting unit that sets a charge accumulation period in an image sensor to an integral multiple of ½ a flicker period, a second setting unit that, when a horizontal scan period, which is a period after commencement of reading out a preset line of the image sensor until commencement of reading out a line to be read out next, is changed to be shorter, sets a charge accumulation period of the image sensor immediately after a change in the horizontal scan period to a period that is an integral multiple of ½ the flicker period and is shorter than the charge accumulation period that has been set by the first setting unit, and a timing controller that controls the image sensor to achieve the charge accumulation periods set by the first and second setting units.

Abstract: Method and apparatus for removing image artifacts from an image of a scene illuminated by a periodically varying light source such as a fluorescent light source. The image is represented by image data, and the method has the steps of determining a flicker function and processing the image data using the flicker function to remove the image artifacts from the image. The method and apparatus operate on data of a single image, do not require any additional input other than values of the flicker and frame periods, and do not require that the flicker be independently monitored. The method and apparatus is suitable for removing image artifacts from an image represented by image data collected by a CMOS image sensor utilizing a rolling shutter.

Abstract: A flicker frequency detection method includes defining a plurality of adjacent sensing sections of the same size on a display panel based on an M Hz frequency, an N Hz frequency and the panel resolution, calculating a reference average signal detected by a first sensing section, calculating a first average signal detected by an (n+1 )th sensing section, calculating a second average signal detected by an (m+1)th sensing section, calculating a first difference value between the first and reference average signals, calculating a second difference value between the second and reference average signals, determining a relationship between the first and second difference values, and outputting corresponding signals based on the relationship between the first and second difference values. The ratio between the area covered by the first through mth sensing sections and that covered by the first through nth sensing sections is proportional to the ratio between M and N.

Abstract: In the case where an input signal is an interlace signal such as NTSC signal, a flicker interference as aliasing interference brought about by the sampling theorem is contained in a region where a vertical frequency component is high. Accordingly, in the conventional processing in which rate of change in gradation is improved by making a drive voltage of liquid crystal at the time of change in gradation larger than normal liquid crystal drive voltage to increase response rate of the liquid crystal panel, interference component is also emphasized. As a result, quality level of a video picture to be displayed on the liquid crystal panel is deteriorated. The invention provides a compensation device capable of improving rate-of-change in gradation at a part where there is no flicker interference and changing rate-of-change in gradation to suppress the flicker at a part where there is any flicker interference.

Abstract: A method of capturing an image of a scene includes providing an imaging device having an array of pixels. Each pixel is configured to provide a pixel output. The method also includes determining a frequency of light produced by a light source illuminating the scene and capturing an image of the scene using the pixel array. A first capture time for one or more pixels in the array is different from a second capture time of one or more other pixels in the array. The method further includes, for each pixel in the array, determining a relative phase of the light with respect to the capture time of the pixel, determining a compensating gain based on the relative phase of the light and the frequency of the light, and adjusting the pixel output of the pixel in relation to the compensating gain.

Abstract: In a method for imaging, a plurality of image sensor elements is used, which generate different output signal values when using different exposure times. For each image sensor element, an image signal value is generated by generating a first output signal value when using a first exposure time and an associated second output signal value using a second exposure time. If the first output signal value does not exceed a threshold value associated thereto, the image signal value is calculated using a first calculating rule on the basis of the first output signal value. If the first output signal value exceeds the threshold value, the image signal value is calculated using at least a second calculating rule on the basis of at least the second output signal value.

Abstract: To determine a more appropriate WB gain. A first image data, which is obtained by way of photographing essentially the same subject as that of a main image intended by a user without firing a strobe light for preliminary illumination, and a second image data, which is obtained by way of photographing the same while firing the strobe light for preliminary illumination, are captured. Subsequently, a typical value of each of blocks constituting the first and second image data and the type of a light source of the same are acquired as block information. The thus-acquired pieces of block information about the first and second image data are compared with each other, to thus acquire the tendency of a color change in subject before and after preliminary illumination. An environment light source is estimated on the basis of the obtained tendency of a color change.

Abstract: The quality of recorded images with for example a high speed camera can be detoriated by light modulation which is a consequence of for example gas-discharge lamps running at a lower frequency with respect to the camera. A camera according to the invention provides light modulation removal by handling fields of the image different depending on the light modulation.

Abstract: Turning on and off of the light source illuminating an object to be imaged is judged based on brightness changes in small and large areas set up in the frame and an electric charge storage time for each pixel is set up to be equal to the turning-on-and-off period of the light source or an integral multiple thereof. The charge storage time is changed over responsive to the turning-on-and-off period of the light source or the integral multiple thereof to set up a stored light amount for each pixel stepwise and difference in the stored light amount between steps is interpolated by continuous gain control of read-out signals of pixels.

Abstract: An image device, such as a digital camera, detects specific repeating patterns of signal variations by processing columnar information from the device's two-dimensional sensor array used to generate images. In one embodiment, the columnar information is derived from calculating row averages for two image frames, with each row average being a computed average of the multiple signal intensities generated from some or all of the sensors within a particular row. After the columnar information is determined for each of the two frames, a difference signal is generated as a sequence of the differences between the row averages for the first frame and the row averages for the second frame. This row averaging and frame differencing removes a large percentage of the signal energy that is not a result of the artifact of interest, such as the flicker generated by illumination having intensity fluctuations at 100 Hz or at 120 Hz.

Abstract: A flicker correction apparatus for correcting a flicker component of an image signal obtained by imaging an object using an imaging device is provided. The apparatus comprises an image average calculation section for calculating an average of the image signal, a flicker frequency calculation section for calculating a flicker frequency, a flicker data extraction section for extracting flicker data using the average of the image signal and the flicker frequency, a flicker determination section for determining the presence or absence of a flicker phenomenon using the flicker data, a flicker correction amount calculation section for calculating a flicker correction amount using the flicker data, and a flicker correction section for removing the flicker component of the image data using the flicker correction amount.

Abstract: A method for achieving flickerless operation of imagers using a rolling shutter, including the steps of detecting flicker in an image frame and adjusting an integration time such that the integration time is an integer multiple of a light intensity period, is described. The method reduces the task of detecting flicker to detecting a spatial sine wave in the image frame by subtracting two image frames from each other. The subtraction reduces or eliminates image content from the image frames and makes the detection process independent of image content. This method can be practiced based on a very short sequence of image frames (as few as two image frames) and is virtually insusceptible to motion of the image content. Adjustments to the integration time are made by changing the horizontal blanking time of the imager and, thereby extending the duration time of each row of said image frame.

Abstract: An image capture apparatus which is compact and structurally simple and allows for prevention of a flicker noise, a method of capturing an image which allows for prevention of a flicker noise, and a mobile terminal using the apparatus and the method, are provided. In the image capture apparatus, a vertical cycle is adjusted so as to maintain 20 fps or 20/2m (m is an integer) fps, thereby to prevent a flicker noise in an image as obtained. To this end, in the image capture apparatus, a frequency of a horizontal transfer clock, a horizontal count level and a vertical line count level may be adjusted. Further, a fraction count is provided to adjust the length of one vertical cycle. Moreover, the image capture apparatus may be incorporated in a mobile terminal.

Abstract: A digital camera printing user interface automatically selects and presents sets of printing options for printing parameters such as printed image size and paper size in accordance with location information. The location information may comprise the current location of the digital camera or an indication of where an image to be printed was captured.

Abstract: It is an object of the invention to provide a method of reducing flicker noises in an X-Y address type solid-state image pickup device for reducing flicker noises generated by a fluorescent light for room illumination when taking a picture in door. A configuration is provided in which signal storage time ts resulting in no flicker noise under a fluorescent lamp having an emission frequency of 120 Hz is preset (step S1); average luminance of image data is calculated for each frame in a predetermined average luminance detection area allocated in the frame (step S2); a difference in average luminance is calculated between frames (step S3); and the signal storage time ts is changed based on the difference in luminance (steps S4, S5 and S6).

Abstract: The present invention provides a method and apparatus for calibrating a black level in an imager to reduce flicker noise. A first and a second range is set. The first range corresponds to a range that is larger than a noise level at a highest PGA gain. The second range corresponds to a range that is smaller than a level which reduces an ADC dynamic range too much due to a large black level. The ranges may be adjusted to changes in an imager in real time. When the black level is within the second range a determination is made as to whether the black level has been calibrated before. When it has, the DAC output is held constant. Otherwise the DAC code is adjusted such that the black level is moved toward the first range. A small step size is used in adjusting the DAC code in order to reduce flicker. Step sizes may be adjusted according to the black level in relation to the ranges. A small step size is used when the black level is within the second range.