Abstract: An adaptive gain and offset control for a digital video analog to digital converter is provided. A gain indicator and/or an offset indicator, which are used as inputs control signals to an analog-to-digital converter, are determined based on a detected maximum level and a detected blanking level from an input video signal. The gain and offset indicators may be determined independently from a minimum level of the video signal.

Abstract: Disclosed is an automatic video gain control circuit, which includes an analog to digital converter, an envelope detector and an extreme value detector. The analog to digital converter converts an analog video signal to a digital video signal. The envelope detector detects a baseband amplitude signal according to the digital video signal. The extreme value detector generates an extreme value to control RF signal gain.

Abstract: A video signal processing apparatus includes: a gain inverse correction means for giving an inverse correction gain resulting in an inverse correction characteristic to a gain to a video signal subjected to automatic gain control and outputting the video signal; a texture component removing means for removing a texture component from the video signal output from the gain inverse correction means; a gain inverse-inverse correction means for giving an inverse-inverse correction gain to the video signal output from the texture component removing means; a texture component extracting means for extracting a texture component signal, utilizing the video signal output by the gain inverse correction means and the video signal output by the texture component removing means; and a signal synthesizing means for synthesizing a structure component signal based on the video signal output by the gain inverse-inverse correction means and the texture component signal to output a video signal.

Abstract: A video apparatus has a receiver for receiving and converting an RF signal into a video signal. The video signal is then processed (notably encoded) into an encoded digital stream by processing means. The processing means is adjusted based on an indicator of a characteristic of the RF signal.

Abstract: A method for adjusting image is applied to an image output device. According to the method, the image output device firstly obtains a current image frame including plural pixels, and analyzes an intensity of an input image signal value of each pixel. The image output device defines each pixel having the input image signal value being smaller than a critical value as a dark pixel, and counts a number of the dark pixels to obtain a ratio of the dark pixels among all the pixels to serve as a dark pixel ratio. The image output device determines an image adjusting curve equation according to the dark pixel ratio, substitutes the input image signal values to the image adjusting curve equation, and obtains output image signal values of the pixels. Finally, the image output device combines all the output image signal values to obtain a final output image frame.

Abstract: A request recognition section (373) recognizes an input operation for a source switching request to switch broadcast program contents extracted from broadcast waves to contents recorded in a recording and reproducing apparatus to display the contents on a display unit (350). Values of a plurality of setting factors such as brightness, contrast, and black level related to picture quality, which correspond to the source to be switched, specified corresponding to the previous contents source are read from a memory (360). Predefined values of the setting factors set corresponding to the previous contents source are compared with values newly read, and the values of the respective setting factors are sequentially changed stepwise. It is possible to prevent a flicker on a screen caused by a sudden change in the picture quality during processing of changing the picture quality, thereby favorably adjusting the picture quality.

Abstract: An automatic video gain adjustment method in which an automatic gain equalizer is used. The method includes steps of: using a processor to read and analyze a video signal and compare the video signal with a standard value to judge whether the video signal matches the standard value; using a gain regulator to automatically adjust the amplitude of the video signal in case the video signal fails to match the standard value, the gain regulator then generating an adjusted video signal; and using the processor to receive the adjusted video signal and transmit the adjusted video signal to a remote-end receiving device. By means of the automatic video gain adjustment method, the video signal can be automatically and more conveniently adjusted to match the standard value.

Abstract: A video processor includes a video filter and a calculation circuit. The video filter performs a low-pass filtering operation on first frame data to obtain brightness distribution data. The calculation circuit obtains difference data between the brightness distribution data and second frame data. The calculation circuit multiplies the difference data and a weighting parameter together to obtain a product, and then summates the product and the second frame data together to generate processed frame data.

Abstract: Disclosed is a video signal processing device and a method of processing gradation capable of improving the contrast ratio and the user satisfaction of a plasma display device. The video signal processing device includes a position detecting unit for detecting positions of pixels to be displayed in a frame, a sub region detecting unit for detecting a central region including a reference point formed of at least one pixel in the frame and sub regions surrounding the central region, and a compensating unit for differently compensating brightness of pixels positioned in the sub regions and brightness of pixels positioned in the central unit.

Abstract: A digital level control circuit, such as an Automatic Gain Control, includes a plurality of digitally selectable signal levels with transitions between levels gradually varied to avoid signal output level discontinuities. An up/down counter may be used to incrementally stepwise transition an output signal between the digitally selectable output levels. Stepwise application of a control signal to the appropriate switching elements (e.g., FETs) forming an attenuator circuit may be implemented to moderate a switching time of the switching elements to provide a more gradual transition between element operating states. A deglitch circuit may be employed to latch the switching elements to achieve the desired state at the end of a desired switching transition period.

Abstract: A technique for providing stable tracking performance to an AGC loop circuit comprises amplifying a wideband radio frequency signal; detecting signals and blockers adjacent to the radio frequency signal; lowering a gain of the radio frequency signal; mixing a local oscillator signal with the radio frequency signal; shifting a frequency of the radio frequency signal from a radio frequency to an intermediate frequency; continuously varying a gain of the intermediate frequency signal; converting the intermediate frequency signal into a digital output signal; comparing the digital output signal with predefined thresholds comprising an upper threshold and a lower threshold; switching a post mixer amplifier (PMA) to a high gain state when an input of a variable gain amplifier (VGA) is greater than the upper threshold, and switching the PMA to a low gain state when an input of the VGA is lower than the lower threshold.

Abstract: An apparatus and method for processing a video signal includes means for receiving the video signal, means for analyzing the video signal based upon a user supplied set of instructions, means for processing the video signal in accordance with the analysis, and means for outputting the processed video signal.

Abstract: A method for contrast enhancement of a video signal comprises receiving a video signal frame, gathering statistics about the video signal frame, calculating the effective input dynamic range of the video signal frame, calculating the effective output dynamic range of the video signal frame, and constructing a transform to enhance the picture in the video signal frame by mapping the effective input dynamic range to the effective output dynamic range via the transform.

Abstract: An AGC circuit is provided which includes a first AGC detector circuit that switches whether the AGC voltage is output or not, a second AGC detector circuit that always outputs the AGC voltage, a first resistor with a high impedance compared to a tuned frequency of which one end is connected to an output port of the first AGC detector circuit and the other end is connected to an output port of the second AGC detector circuit, and a switching element that is provided between the other end of the first resistor and a ground, in which an output source that outputs the AGC voltage to the amplifier can be switched to the first AGC detector circuit or the second AGC detector circuit by an On/Off operation of the switching element.

Abstract: A scene change detecting circuit (1) detects a scene change of video. An average luminance level operating circuit (2) calculates an average luminance level (APL) of a video signal (VD). A luminance overdrive amount calculating circuit (3) calculates a luminance overdrive amount (OD) based on the average luminance level (APL). A time-linked attenuating circuit (7) outputs a power consumption limit correction amount (PA) by attenuating the luminance overdrive amount (OD) with an elapse of time from a point in time of detecting the scene change. An adder (8) adds the power consumption limit correction amount (PA) and a reference power consumption limit value (Lp) to output the addition result as a power consumption limit amount (PL). An ABL circuit (4) calculates a luminance limit amount (BL) based on luminance limit characteristics, the average luminance level (APL) and the power consumption limit amount (PL).

Abstract: A picture quality when reducing the brightness or the contrast of the picture on a plasma panel shall be improved. For this purpose there is provided a driving apparatus including brightness/contrast control means for receiving video input data for modifying the video levels of the video input data in accordance with external adjustment data and for outputting modified video data. First power measurement means measure a power level of the modified video data and supply a first power level. Second power measurement means measure a power level of the video input data and supply a second power level. Generator means generate a third power level comprised between the first power level and the second power level or equal to the larger one to data processing means. The data processing means calculate the maximum number of sustain pulses per frame applicable to the modified video data on the basis of the third power level and control the display of the modified video data on the plasma display panel.

Abstract: Which types of subject among a predetermined plurality of types of subject are contained in an image represented by input image data are detected. Features regarding the detected subject types are calculated in a feature calculating circuit based upon the image data. In accordance with the features calculated, the gain for every subject type is calculated. The gains are weighted and averaged using degrees of importance that have been input for every subject type. The input image data is corrected based upon applicable gains obtained by the weighted averaging.

Abstract: A digital receiver includes an analog front-end circuit, an automatic-gain controller, a compensation circuit, and a demodulator. The analog front-end circuit receives an input signal, adjusts an average amplitude of the input signal, and converts the adjusted input signal to generate a digital signal according to a control signal. The automatic-gain controller is coupled to the analog front-end circuit for generating the control signal feedback to the analog front-end circuit according to the digital signal. The compensation circuit is coupled to the analog front-end circuit for detecting an average amplitude of the digital signal to generate a detecting result and for determining whether to compensate the average amplitude of the digital signal to generate a compensated digital signal according to the detecting result. The demodulator is coupled to the compensation circuit for demodulating the compensated digital signal to generate an output signal.

Abstract: The present invention aims at obtaining a high-quality video signal by reducing tone jumps. A second grayscale conversion characteristic is calculated from a video signal to which a first grayscale conversion process has been applied using a first grayscale conversion characteristic used to convert an M-bit video signal into an N-bit video signal, where M and N are integers and M is larger than N. The first grayscale conversion characteristic is corrected by using the second grayscale conversion characteristic. The first grayscale conversion process is applied to the video signal by using the corrected first grayscale conversion characteristic.

Abstract: A method of processing a video sequence in a computer vision system is provided that includes receiving a frame of the video sequence, computing a gain compensation factor for a tile in the frame as an average of differences between background pixels in the tile and corresponding pixels in a background model, computing a first difference between a pixel in the tile and a sum of a corresponding pixel in the background model and the gain compensation factor, and setting a location in a foreground mask corresponding to the pixel based on the first difference.

Abstract: An image correction circuit capable of preventing a loss of gray levels in a luminance region at the time of the direct current level conversion of a luminance signal to improve the quality of a displayed image. The image correction circuit detects an average peak level of input image data in each image frame, and corrects the input image data to lower the luminance of input image data in an intermediate luminance region according to the average peak level while reducing the luminance of input image data at a predetermined rate in at least of a low luminance region.

Abstract: The present invention aims at obtaining a high-quality video signal by reducing tone jumps. A second grayscale conversion characteristic is calculated from a video signal to which a first grayscale conversion process has been applied using a first grayscale conversion characteristic used to convert an M-bit video signal into an N-bit video signal, where M and N are integers and M is larger than N. The second grayscale conversion characteristic is corrected by using the first grayscale conversion characteristic. A second grayscale conversion process is applied to the video signal by using the corrected second grayscale conversion characteristic.

Abstract: A signal processing circuit includes an auto gain control circuit and amplifies a signal with an amplification ratio determined based on a synchronous signal level having a positive potential with respect to a black level included in a high definition television video signal. In consequence, during the processing of the high definition television video signal, the signal processing is performed with a desired amplification ratio.

Abstract: A contrast control apparatus includes a memory for storing input image signals within one frame and an image reducing unit for selecting at least one image signal of the input image signals. An accumulation value calculating unit calculates accumulation values for predetermined sampling gray values with respect to the selected image signal. An image characteristic decision unit determines at least one characteristic of the selected image based on the accumulation values. A contrast control function calculating unit calculates a contrast control function based on the characteristic of the selected image. A contrast controller controls contrast of the image signals stored in the memory according to the contrast control function.

Abstract: An image processor includes: an receiving module configured to receive a video signal of a content; an image quality adjusting module configured to adjust image quality of the video signal received by the receiving module using image quality adjustment parameters including at least a contrast-related parameter; a 3D video detecting module configured to determine whether the video signal is of a 3D content; and a control module configured to control the image quality adjusting module to adjust the image quality of the video signal using the contrast-related parameter being set to a second parameter setting for enhancing contrast more than at a first parameter setting, when the video signal is determined to be the 3D content by the 3D video detecting module while the image quality adjusting module is adjusting the image quality using the contrast-related parameter being set at the first parameter setting.

Abstract: An apparatus for controlling black stretch includes a black stretching unit, an offset adjusting unit and an output unit. The black stretching unit performs black stretch processing on a video signal less than or equal to the maximum value of a black stretch control range in response to a slope of black stretch. The slope of black stretch corresponds to a region between a minimum value and a maximum value of the black stretch control range. The offset adjusting unit adjusts an offset of the black-stretched video signal. The output unit outputs an output video signal corresponding to the offset-adjusted video signal when the offset-adjusted video signal has a positive value in a region less than or equal to the minimum value, and outputs the output video signal corresponding to 0 when the offset-adjusted video signal has a negative value in the region less than or equal to the minimum value.

Abstract: The appearance of image details can be preserved and/or enhanced by applying contrast adaptive gain to the high spatial frequency component of the luminance information. The image details in bright and/or dark regions can be further boosted by applying a local mean adaptive gain. The contrast transfer mapping curve for luminance contrast enhancement can be re-scaled to account for the applied gain. The re-scaling may be performed from frame to frame of displayed video. The re-scaling may be temporally controlled for subsequent frames to make the re-scaling change gradually to prevent flickering.

Abstract: Image quality adjustment of an inputted image signal is performed with higher accuracy to display a more preferable image to the user. An attribute information determining unit obtains first attribute information indicating the format of the inputted image signal and second attribute information indicating transmission characteristics of the image signal. An image quality adjustment value calculating unit calculates optimal image quality adjustment values for the image signal from the obtained first and second attribute information. An image processing unit adjusts the image quality of the image signal based on the optimal image quality adjustment values and then outputs the image to an image display. The second attribute information includes the bit rate, resolution, and frame rate of the image signal.

Abstract: This invention relates to an apparatus for processing an input image including M input pixels. Each of the M input pixels respectively has an input gray scale. The apparatus includes a gain generating module, a contrast enhancing module, and a Gamma adjusting module. The gain generating module generates a contrast gain and a minimum input gray scale in accordance with the input gray scales of the M input pixels. The contrast enhancing module adjusts the input gray scales in accordance with the contrast gain and the minimum input gray scale, to generate an intermediate image. The intermediate image includes M intermediate pixels, and each of the M intermediate pixels respectively has an intermediate gray scale. The Gamma adjusting module adjusts the intermediate gray scales lower than a first threshold in accordance with the contrast gain and outputs the adjusted intermediate image as an output image.

Abstract: A video image display device is provided. The device includes an expansion factor deriving unit deriving and outputting an expansion factor for each frame of the video image data, for use in a luminance range expansion process for expanding a luminance range of the video image data on the basis of an image characterizing quantity related to the luminance of the video image data corresponding to the frame; a luminance range expansion processing unit performing the luminance range expansion process to the video image data on the basis of the expansion factor output from the expansion factor deriving unit; and a scene-change detecting unit detecting a change in a screen state of a present frame into a black screen state on the basis of the video image data and detecting a scene-change indicating that the scene of the video image has changed.

Abstract: Provided are an apparatus and method for automatically adjusting luminance, and more particularly, apparatus and method for automatically adjusting luminance per region in plurality of luminance regions of an image to be displayed according to its average luminance value. An average luminance of an image is detected, and then contrast and brightness of image is automatically adjusted according to detected average luminance. Amplification of contrast and brightness is increased to brighten an image in an image with low luminance and reduced to suppress image dazzle in an image with high luminance, thereby providing user with an image of appropriate brightness, irrespective of original brightness. It is possible to prevent diversion of image by dividing its luminance level into a plurality of regions and controlling contrast and luminance per region. Further, a buffer region between luminance regions prevents flickering of image on a screen due to diversion of an adjustable gain.

Abstract: It is an object of the present invention to output a clear, expanded image wherein step-shapes or chain-shapes of oblique lines are reduced, distortion is eliminated and no constituent lines of fonts or graphics are missing.

Abstract: An image contrast evaluation method is disclosed. First, focusing is performed based on the contrast value of an image rendered by a lens on optical sensors, wherein the calculation of the contrast value comprises: selecting an area of the image, calculating the absolute value of brightness difference between each neighboring pixel, and selecting a specific value there from as the contrast value of the image based on a distribution of the calculated absolute values of the brightness differences.

Abstract: A color management unit is architected to achieve higher-quality appearance used in various video formats and to enable improvements in picture contrast and colorfulness. The color management unit comprises an optional input color space converter to convert the input digital video to a desired color space, an adaptive contrast enhancer to apply contrast improvement algorithms in response to different scenes in either manual or automatic modes, intelligent color remapping for enhancing selected colors, sRGB compliance to produce a video display that is uniform over different monitors, global color and brightness controls to combine global processing and color conversion, gamut compression to maintain pixel validity in color space conversion, and gamma correction to compensate for nonlinear characteristics of an output display.

Abstract: An image processing apparatus for improving clarity and an image processing method are provided. An image processing apparatus includes an image receiving unit, and an image processing unit which allows luminance of an image to be within a preset range of luminance and adjusts clarity of the image. Accordingly, the problem that the luminance exceeds a digital value may be prevented, and clarity of the image may be effectively improved.

Abstract: A digital television combination integrated circuit is employed which includes a video signal D/A converter which converts a digital video signal to an analog video signal, and an audio signal D/A converter which converts a digital audio signal to an analog audio signal; there are provided a level shift circuit which extracts a luminance signal in the video signal which is outputted from the video signal D/A converter, and a low pass filter which extracts the DC component of the output signal of this level shift circuit; and the output signal of this low pass filter is supplied as a control voltage signal for gain control of an audio amplification circuit.

Abstract: The invention achieves a visual processing device that can execute precise contrast adjustment on image signals that have been input and that does not cause discrepancies in the output timing of the image signals that are output. The visual processing device is provided with a gain-type visual processing portion that outputs a first gain signal having predetermined gain characteristics with respect to the input image signal, and a correction portion that corrects the input image signal based on the first gain signal.

Abstract: The invention achieves a visual processing device that can execute precise contrast adjustment on image signals that have been input and that does not cause discrepancies in the output timing of the image signals that are output. The visual processing device is provided with a gain-type visual processing portion that outputs a first gain signal having predetermined gain characteristics with respect to the input image signal, and a correction portion that corrects the input image signal based on the first gain signal.

Abstract: An image processor includes: an receiving module configured to receive a video signal of a content; an image quality adjusting module configured to adjust image quality of the video signal received by the receiving module using image quality adjustment parameters including at least a contrast-related parameter; a 3D video detecting module configured to determine whether the video signal is of a 3D content; and a control module configured to control the image quality adjusting module to adjust the image quality of the video signal using the contrast-related parameter being set to a second parameter setting for enhancing contrast more than at a first parameter setting, when the video signal is determined to be the 3D content by the 3D video detecting module while the image quality adjusting module is adjusting the image quality using the contrast-related parameter being set at the first parameter setting.

Abstract: A driving method and apparatus for a liquid crystal display is provided in which a contrast ratio of data to be displayed can be expanded and the brightness of a back light can be changed using an accumulated result of a plurality of frames. In the driving method, data to be displayed is converted into brightness components and arranged into a histogram for each frame. Second data having an expanded contrast is generated using the histograms of at least two frames, including the histogram of the current frame. Averages of the histograms are calculated and used to control the brightness of the back light. The averages may be weighted such that frames closer to the current frame have a larger effect.

Abstract: There is provided an image processing apparatus, an image display and an image processing method which are capable of preventing an unnatural change in image quality to image processing. A luminance distribution detecting circuit detects a luminance distribution as the histogram distribution of YUV signals. A gain calculating circuit and a gain limiter detect a gain variation on the basis of luminance distribution data. The gain limiter limits the gain variation to a gain variation threshold or less. The gain limiter and a delay circuit carry over the gain variation of a portion exceeding the gain variation threshold to the next image frame so as to modify the gain variation. A ? correction circuit performs image processing (contrast control) on the YUV signals on the basis of the gain variation modified.

Abstract: The present invention relates to method for managing gain value for each channel of a TV set, includes steps: signaling a tuner to receive broadcasting signals of the channel in response to a channel selection command; reading a predetermined gain value of the channel from a setting table; amplifying and outputting audio signals extracted from the broadcasting signals of the channel according to the predetermined gain value of the channel; signaling a gain control unit to adjust a current gain value to an adjusted gain value if receiving a gain adjustment command; amplifying the audio signals of the channel according to the adjusted gain value; calculating an integrated gain value according to the adjusted gain value and the predetermined gain value; and updating the predetermined gain value of the channel using the integrated gain value. The present invention also provides a corresponding TV set.

Abstract: An automatic gain control (AGC) circuit based on a cascade of a step automatic gain control unit and a second automatic gain control unit connected to adjust their gain in a synchronized manner to result in a combined impulsive gain variation. Hereby it is possible, e.g. to use a step automatic gain control unit instead of a continuous automatic gain control unit in an RF part of a TV tuner without resulting in visual artifacts—this applies both for digital and analog TV tuners. According to a preferred embodiment, the synchronization between the two automatic gain control units may be achieved by the first automatic gain control unit generating a control signal upon gain adjustment, this control signal serving to speed up a loop bandwidth controlling gain change of the second automatic gain control unit. In another embodiment, the control signal generated by the first automatic gain control unit is used to control a gain step of the second automatic gain control unit.

Abstract: An automatic gain control device in a digital broadcast receiver is provided. The device is constructed to include an AGC for receiving an input signal and a predetermined power reference value to thereby obtain a gain error value, determining one of a plurality of operational areas according to a received AGC step control signal, and generating an RF gain control signal and an IF gain control signal according to the gain error value; and a lock detector for receiving the gain error value and the predetermined power reference value and thereby generating the AGC step control signal and an AGC lock/unlock signal.

Abstract: A digital receiver includes an analog front-end circuit, an automatic-gain controller, a compensation circuit, and a demodulator. The analog front-end circuit receives an input signal, adjusts an average amplitude of the input signal, and converts the adjusted input signal to generate a digital signal according to a control signal. The automatic-gain controller is coupled to the analog front-end circuit for generating the control signal feedback to the analog front-end circuit according to the digital signal. The compensation circuit is coupled to the analog front-end circuit for detecting an average amplitude of the digital signal to generate a detecting result and for determining whether to compensate the average amplitude of the digital signal to generate a compensated digital signal according to the detecting result. The demodulator is coupled to the compensation circuit for demodulating the compensated digital signal to generate an output signal.

Abstract: A video apparatus having a display module and a method of controlling the same are provided, whereby an electric field strength or automatic gain control (AGC) signal is recognized from a received broadcast signal and a power supply mode of the display module is controlled according to a level of the recognized AGC signal, to prevent an overheating of the display module without using an additional device. The video apparatus includes a display module for displaying a broadcast signal received via a broadcast channel, the display module being selectively driven according to one of a plurality of power supply modes; and a controller for controllably setting the power supply mode of the display module according to the strength of an electric field of the received broadcast signal, the controller maintaining the set power supply mode if the electric field strength lies between lower and upper thresholds defining a threshold region.

Abstract: A method for increasing dynamic range of original image data representing an image comprises applying an expansion function to generate from the original image data expanded data having a dynamic range greater than that of the original image data and, obtaining an expand map comprising data indicative of a degree of luminance of regions associated with pixels in the image. The method then combines the original image data and the expanded data according to the expand map to yield enhanced image data. Apparatus for boosting the dynamic range of image data comprises a dynamic range expander that produces expanded data, a luminance analyzer that produces an expand map and a combiner that combines the original and expanded data according to a variable weighting provided by the expand map.

Abstract: The invention achieves a visual processing device that can execute precise contrast adjustment on image signals that have been input and that does not cause discrepancies in the output timing of the image signals that are output. The visual processing device is provided with a gain-type visual processing portion that outputs a first gain signal having predetermined gain characteristics with respect to the input image signal, and a correction portion that corrects the input image signal based on the first gain signal.

Abstract: It is possible to inhibit side effects even when an image that has sharp edge regions has been input. The invention is provided with a spatial processing portion (10) that outputs surrounding image information US from an image signal that has been input, a control signal generation portion (40) that outputs an effect adjustment signal MOD according to the degree of flatness of the edge proximal region, an effect adjustment portion (20) that outputs a synthesized signal MUS that is synthesized changing the ratio of the image signal IS and the surrounding image information US according to the effect adjustment signal MOD, and a visual processing portion (30) that visually processes the image signal IS based on the synthesized signal MUS and the image signal IS.

Abstract: An image display adjustment system comprises a display setup application executable by a processor and configured to, in response to detecting at least one characteristic associated with a display device, automatically cause an adjustment image to be displayed on the display device and an image adjustment process to be performed for the display device using the adjustment image.