Including Flicker Detection (e.g., Fluorescent) Patents (Class 348/226.1)
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Patent number: 7034870Abstract: An image pickup apparatus includes a solid-state imaging device, an accumulating section, first and second imaging parameter setting sections, a calculating section, a flicker detecting section, and a switching section. The accumulating section calculates a projection output value of a predetermined line in a frame. The calculating section calculates inter-frame variations of the projection output values, and calculates a flicker index from the variations of a predetermined number of frames. The flicker detecting section detects the flicker from the index, and controls the switching section in response to the detection result of the flicker, so that the switching section selects either the setting signals from the first imaging parameter setting section or the setting signals from the second imaging parameter setting section.Type: GrantFiled: August 6, 2001Date of Patent: April 25, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hidetada Nagaoka, Narihiro Matoba, Takeo Fujita, Hiroaki Sugiura, Tetsuya Kuno
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Patent number: 7030916Abstract: An image pickup system includes photodiodes with color filters. A first color filter group includes visual light color filters, and a second color filter group includes a long red color filter at 640 nm or longer or a color filter at 580 nm and one of the visual light color filters. An infrared cut filter covers all the filters. A control circuit includes a fluorescent lamp distinguishing circuit for distinguishing a fluorescent lamp from other illuminating light sources by a ratio of an output signal from the photodiode with the long red filter to an output signal from the photodiodes with the visual light color filters; and a white balance control circuit for adjusting a white balance so as to match the illuminating light source distinguished by the fluorescent lamp distinguishing circuit.Type: GrantFiled: September 17, 2002Date of Patent: April 18, 2006Assignee: Fuji Photo Film Co., Ltd.Inventor: Yasuo Aotsuka
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Patent number: 7010324Abstract: A method for automatically removing strobe in a digital image capturer of a mobile communication apparatus and a mobile communication apparatus thereof are provided. The method comprises: providing a local area data by the mobile communication apparatus, the local area data indicating an area the mobile communication apparatus is located; generating a power frequency data corresponding to the local area data; and setting the digital image capturer based on the power frequency data to remove the strobe. The method may further includes the mobile communication apparatus detecting/communicating a telecommunication service network, the telecommunication service network providing a mobile communication service; and the telecommunication service network sending the local area data to the mobile communication apparatus.Type: GrantFiled: June 2, 2004Date of Patent: March 7, 2006Assignee: Inventec Appliances Corp.Inventors: David Ho, Tony Tsai, Cheng Chang
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Patent number: 7009642Abstract: A method and apparatus for detecting the presence of artificial illumination in a scene powered by alternating current by sampling the light in a scene at a periodic rate.Type: GrantFiled: October 30, 2001Date of Patent: March 7, 2006Assignee: Hewlett-Packard Development Company, L.P.Inventors: Gregory V Hofer, Jason E Yost
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Patent number: 6999118Abstract: The present invention relates to a method for driving a solid-state image pickup device and a camera provided with the driving function. In the method for driving the solid-state image pickup device and the camera according to the present invention, the frame rate of the image pickup device is varied according to the frequency of illumination or the brightness. Alternatively, the frame rate of the image pickup device is varied and an electronic shutter is driven at the same time according to the brightness. Consequently, it is possible to suppress occurrence of flicker and give a liberal brightness condition under which an image can be picked up.Type: GrantFiled: November 27, 2001Date of Patent: February 14, 2006Assignee: Sony CorporationInventor: Ryoji Suzuki
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Patent number: 6989860Abstract: A method and apparatus is disclosed for auto-exposure control in a scene under artificial illumination that synchronizes the exposure control algorithm and final image capture with the intensity variations in the artificial illumination.Type: GrantFiled: October 30, 2001Date of Patent: January 24, 2006Assignee: Hewlett-Packard Development Company, L.P.Inventors: Gregory V Hofer, Jason E Yost
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Patent number: 6912321Abstract: A method for compensating a digital image for the effects of flare light in order to generate an enhanced digital image operates upon a source digital image derived from an original scene affected by imaged flare light, wherein the source digital image includes a plurality of pixels with a known relationship to the intensity of light corresponding to the original scene. A first flare control parameter relating to the intensity of imaged flare light and a second flare control parameter relating to the average intensity level of imaged light in the original scene are derived from the source digital image, and a flare compensation function is calculated using the first and second flare control parameters. An enhanced digital image is then generated from the flare compensation function and the source digital image.Type: GrantFiled: March 22, 2002Date of Patent: June 28, 2005Assignee: Eastman Kodak CompanyInventor: Edward B. Gindele
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Patent number: 6900834Abstract: Lighting flicker in the output of a video imaging device is detected. The video imaging device has a main picture area divided into pixels for producing successive images at a frame rate. A series of signals are produced from at least one additional picture area adjacent the main picture area, with the additional picture area having a size substantially larger than a pixel. Each of the signals is a function of light incident on the additional picture area in a time period substantially shorter than that of the frame rate. A predetermined number of the signals are accumulated to form a series of compound samples, and the compound samples are filtered to detect components indicating the lighting flicker. The filtering is performed using a bandpass filter tuned to the nominal flicker frequency. The compound samples are formed at a sample rate which is a multiple of the nominal flicker frequency, and the filtering is performed by taking the fundamental output component of a radix-N butterfly.Type: GrantFiled: August 24, 2001Date of Patent: May 31, 2005Assignee: STMicroelectronics LimitedInventors: Robert Henderson, Stewart Gresty Smith, Jonathan Ephriam David Hurwitz, Andrew Murray
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Patent number: 6882363Abstract: An automatic gain controlling circuit controls a gain of a video signal from an imager having an electronic shutter function according to a gain control signal. An average detecting circuit detects an average level of a luminance signal of the video signal. An automatic exposure controlling circuit generates the gain control signal according to the luminance average level in response to a mode signal indicative of the cycles per second of the ac line and generates a timing signal corresponding to the ac line and a shutter speed control signal together with electronic shutter control signal generation circuit at a unit of the voltage variation cycle of the ac line according to the luminance average level such that a shutter interval of the imager is changed stepwise and each of the shutter intervals is an integer times the voltage variation cycle of the ac line.Type: GrantFiled: January 27, 2000Date of Patent: April 19, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kazuo Oda, Masaki Kariya
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Publication number: 20040201729Abstract: 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.Type: ApplicationFiled: October 2, 2001Publication date: October 14, 2004Inventors: Dwight Poplin, Michael J. Zelman, Airell R. Clark, Todd S. Sachs
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Apparatus and method for detecting and compensating for illuminant intensity changes within an image
Publication number: 20040179114Abstract: 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.Type: ApplicationFiled: March 14, 2003Publication date: September 16, 2004Inventors: Christopher Silsby, Dwight Poplin, Richard L. Baer -
Publication number: 20040165084Abstract: A flicker detecting apparatus has integrating means for integrating a pixel level every line in one frame or one field of a video to calculate a line lightness value, extracting means for extracting a fluctuation cycle in a vertical scanning direction of the line lightness value, and deciding means for deciding that a flicker is present when the fluctuation cycle is within a predetermined frequency range. The extracting means calculates a difference made by a fluctuation in the vertical scanning direction of the line lightness value every line, counts the number of continuations of an identical code in the difference, and calculates the count value as fluctuation cycle.Type: ApplicationFiled: December 11, 2003Publication date: August 26, 2004Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.Inventors: Shinji Yamamoto, Toshiyuki Nakashima, Katsumi Tokuyama
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Publication number: 20040109069Abstract: 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.Type: ApplicationFiled: December 10, 2002Publication date: June 10, 2004Inventors: Michael Kaplinsky, Igor Subbotin
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Patent number: 6734840Abstract: Disclosed are a liquid crystal display device and a method and a circuit for driving the same. A gradation difference between the image data to be supplied to the picture elements of the same color of two pixels adjacent in a horizontal direction is detected in a gradation difference judging section, and when the gradation difference is larger than a predetermined gradation difference, it is judged in the same pattern of a size relationship detecting section and a horizontal pattern counting section whether the size relationship between the gradations of the picture elements of the same color of the two pixels repeats in the horizontal direction at least a certain number of times or not. And hence, when the size relationship repeats at least a certain number of times, it is compared with those of a plurality of lines continuously arranged in a vertical direction, and it is judged on the basis of the result of the comparisons whether a flicker occurs or not.Type: GrantFiled: December 12, 2000Date of Patent: May 11, 2004Assignee: Fujitsu Display Technologies CorporationInventors: Syouichi Fukutoku, Kazuhiro Nukiyama
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Publication number: 20040080630Abstract: There are provided a pixel array capable of detecting and removing a flicker noise, an image sensor employing the pixel array and an automatic flicker noise detecting method capable of effectively detecting and removing the flicker noise of the image sensor. For the purpose, a pixel array of an image sensor includes a pixel group, having N×M number of unit pixels, for detecting an image signal, N and M being integers, and a pixel column, allocated along a row direction of the pixel group, for detecting an average frequency of a corresponding pixel row to thereby detect the flicker noise.Type: ApplicationFiled: July 30, 2003Publication date: April 29, 2004Applicant: HYNIX SEMICONDUCTOR INC.Inventor: Chae-Sung Kim
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Patent number: 6717621Abstract: Briefly, in accordance with one embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is adjusted so as to reduce the amount of filtering across temporal discontinuities in the video image sequence. Briefly, in accordance with another embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is dynamically adjusted.Type: GrantFiled: December 26, 2001Date of Patent: April 6, 2004Assignee: Intel CorporationInventor: Thomas P. O'Rourke
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Patent number: 6710818Abstract: A video signal including illumination flicker component is integrated at each of unit areas (horizontal lines) in a frame (field) of the video signal. The integrated level at each of the unit areas at the frame and the integrated level at the corresponding unit area of an adjacent frame are averaged. Dividing is effected between results of the averaging and integrating every unit area. It is judged whether flicker exists in the video signal by frequency-analyzing results of the dividing result at the unit areas. The unit area may be plural adjacent lines where flickering are negligible. The averaging circuit may be circulation type of or FIR filter. Threshold level for judging the flicker is changed according to a shutter speed control signal. Flicker compensation may be executed by controlling shutter speed or the AGC according to flicker judging result. A still condition at a block in a frame may be detected from the integration result at plural frames.Type: GrantFiled: October 6, 2000Date of Patent: March 23, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Misa Kasahara, Kenji Tabei, Makoto Sube
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Publication number: 20040051791Abstract: 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.Type: ApplicationFiled: September 12, 2003Publication date: March 18, 2004Inventor: Seiji Hashimoto
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Publication number: 20040012692Abstract: A flicker detection apparatus takes in a plurality of images having different shutter times from the image sensing element and judges whether flicker occurs or not based on a variation of flicker components extracted from these images so that the accuracy of flicker detection on picking up a normal image can be improved.Type: ApplicationFiled: March 19, 2003Publication date: January 22, 2004Inventor: Shinichi Arazaki
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Publication number: 20040001153Abstract: The object of the present invention is to realize a camera system that can suppress the influence of flickering.Type: ApplicationFiled: May 23, 2003Publication date: January 1, 2004Applicant: Yokogawa Electric CorporationInventors: Youichi Kikukawa, Tooru Katsurai, Kenji Fujino, Takahiro Takahashi
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Publication number: 20030234873Abstract: 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 fclk of a horizontal transfer clock, a horizontal count level Nh1 and a vertical line count level Nv are adjusted. Further, a fraction count is provided to adjust the length of one vertical cycle. Moreover, the image capture apparatus is incorporated in a mobile terminal.Type: ApplicationFiled: November 14, 2002Publication date: December 25, 2003Inventors: Kozo Ishida, Tetsuya Kuno, Koichi Yamashita, Hiroaki Sugiura, Takashi Itow
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Patent number: 6661453Abstract: 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.Type: GrantFiled: March 10, 1999Date of Patent: December 9, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Shunichi Numazaki, Miwako Doi, Minoru Ishikawa, Akira Morishita, Naoko Umeki
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Patent number: 6657659Abstract: In a method of compensating an image signal (10) having a field frequency of substantially N times a mains frequency, in which N≧2, for AC light source induced fluctuations, the image signal (10) and an average signal representing an average image signal content over a given time period are arithmetically processed (14,16-20,8) to obtain a corrected signal (9), in which at least N−1 differences between at least N−1 respective phases of the corrected signal (9) on the one hand, and a selected phase (ph2) other than the N−1 phases of the corrected signal (9), or an average over N fields of the image signal (10), on the other hand, are integrated (14,16), and in which at least N−1 integrated differences are processed (20) to obtain a correction factor for the image signal (10).Type: GrantFiled: April 23, 1999Date of Patent: December 2, 2003Assignee: Koninklijke Philips Electronics N.V.Inventors: Johannes H. J. M. Van Rooy, Antonius G. Moelands
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Patent number: 6630953Abstract: In an imaging apparatus, at least one picture division signal is generated. Every picture represented by a video signal is divided into at least first and second areas in response to the picture division signal. Detection is made as to a mean luminance of the first area and a mean luminance of the second area. A flicker in the first area is corrected to derive a first correction-resultant area in response to the mean luminance of the first area. A flicker in the second area is corrected to derive a second correction-resultant area in response to the mean luminance of the second area. The first correction-resultant area and the second correction-resultant area are combined into a correction-resultant picture.Type: GrantFiled: July 15, 1999Date of Patent: October 7, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Keiji Toyoda, Toshiyuki Sano
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Publication number: 20030112343Abstract: A plurality of flicker detection frames are formed by dividing an image into a plurality of frames. A flicker detection circuit performs detection of luminance data for each of the flicker detection frames. The differences between the luminance data of the preceding frame and the current frame, and between the luminance data of the current frame and the following frame with respect to each of the flicker detection frames are taken, a flicker component is extracted, and the flicker frequency is calculated, by a flicker frequency determination program in a microcomputer. Then, the space between the flicker detection frames in which a crest or trough of the extracted flicker component appears is measured, and the results are converted into the flicker frequency. The frame rate of the image pickup signals is controlled so as not to be synchronized with the flicker frequency.Type: ApplicationFiled: November 14, 2002Publication date: June 19, 2003Inventors: Katsumi Katoh, Eiji Machishima, Toshiaki Kodake
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Publication number: 20030107664Abstract: The present invention relates to a method for driving a solid-state image pickup device and a camera provided with the driving function. In the method for driving the solid-state image pickup device and the camera according to the present invention, the frame rate of the image pickup device is varied according to the frequency of illumination or the brightness. Alternatively, the frame rate of the image pickup device is varied and an electronic shutter is driven at the same time according to the brightness. Consequently, it is possible to suppress occurrence of flicker and give a liberal brightness condition under which an image can be picked up.Type: ApplicationFiled: October 18, 2002Publication date: June 12, 2003Inventor: Ryoji Suzuki
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Patent number: 6573933Abstract: Each brightness value for an image data string for each of a plurality of fields successively stored in a RAM, is integrated by an integrator, and a result of the integration is stored in registers. Image data for a current field stored above is stored in a register, and further a one-field pixel average value for the image data is computed. The computed one-field pixel average value is stored in the register. Image data for each field stored in registers, is integrated by an integrator, and further a three-field pixel average value is computed from the result with the computed average value stored in a register. Computing is executed in a computing section by using the one-field pixel average value, three-field pixel average value, and an Image data string stored in the RAM to generate corrected image data.Type: GrantFiled: October 2, 1998Date of Patent: June 3, 2003Assignee: Fujitsu LimitedInventor: Akinoli Takayama
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Publication number: 20030090587Abstract: A method and apparatus for compensating for the presence of artificial illumination in a scene when auto-focusing a lens is disclosed.Type: ApplicationFiled: October 30, 2001Publication date: May 15, 2003Inventors: Gregory V. Hofer, Jason E. Yost
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Patent number: 6559886Abstract: In a video signal processing method of processing a luminance signal of a video signal generated by causing a CCD to receive light transmitted through color filters, a control signal yf1 is generated by calculating Cy/Y using a complementary color signal Cy and a luminance signal Y, and coring correction is performed to the luminance signal by using the control signal yf1. The characteristic difference between the color filters is suppressed, and, as a result, flickers are suppressed from being generated.Type: GrantFiled: December 2, 1998Date of Patent: May 6, 2003Assignee: Victor Company of Japan, LimitedInventor: Hiroyuki Miyahara
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Publication number: 20030067546Abstract: At first, average brightness of each of frames of a moving image is calculated by a computer. Following that, a moving average along a time axis is calculated for each of the frames so that moving average brightness is generated as a reference data of brightness. Next, difference data between the average brightness and the moving average brightness are generated. Further, the difference data are grouped based on the signs of the reference data. Then, on the basis of the grouped difference data, it is judged whether an unwanted change of brightness is present. Thus, it is automatically and precisely judged whether the unwanted change of brightness such as a flicker is present in the moving image.Type: ApplicationFiled: August 9, 2002Publication date: April 10, 2003Applicant: Minolta Co., Ltd.Inventor: Motohiro Asano
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Patent number: 6519002Abstract: A method having the step of setting a programmable clock to a first frequency; capturing a first set of frames at the first frequency; and then determining a first standard deviation of a first set of average intensities for the first set of frames. In addition, the method also includes the steps of setting the programmable clock to a second frequency; capturing a second set of frames at the second frequency; and determining a second standard deviation of a second set of average intensities for the second set of frames. Then, comparing the first standard deviation with the second standard deviation; and, setting the programmable clock based on the comparison.Type: GrantFiled: August 31, 1998Date of Patent: February 11, 2003Assignee: Intel CorporationInventor: Edward P. Tomaszewski
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Publication number: 20020158971Abstract: 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.Type: ApplicationFiled: December 12, 2001Publication date: October 31, 2002Applicant: FUJITSU LIMITEDInventors: Hiroshi Daiku, Iwao Sugiyama