Abstract: A difference sample data holder of a gamma correction device holds as difference sample data a difference between a corrected signal level and a yet-to-be-corrected signal level for each of multiple sample points set at equal intervals between the permissible minimum and maximum levels of an input video signal. A correction execution unit performs cubic interpolation operation using the difference sample data held in the difference sample data holder, and adds the operated result and the signal level of the input video signal to obtain the signal level of the corrected video signal.

Abstract: Low frequency components are extracted from a video signal for pixels in a specific area of an image carried by the signal. The low frequency components are allocated, based on luminance components of the signal, to gradations ranging from maximum to minimum levels exhibited by the luminance components, luminance histogram data being produced indicating the frequency of gradations for the pixels. The gradations are allocated to the pixels based on the luminance components to produce high-frequency component histogram data indicating the frequency of gradations for specific pixels each carrying a high frequency component. The luminance histogram data is corrected in accordance with the frequency of gradations in the high-frequency component histogram data to produce corrected luminance histogram data. A gradation correction curve is produced for correcting the gradations exhibited by the signal using the corrected data. The luminance components are corrected based on the correction curve.

Abstract: An image processing apparatus according to the present invention extracts a characteristic value of a luminance in relation to respective fields of an input video, and determines the presence of a scene change between adjacent fields. A gamma curve is then generated on the basis of the magnitude of the characteristic value. When a difference in the characteristic value between fields is larger than a predetermined value and a scene change does not exist, the gamma curve to be applied to a subsequent field is modified such that the correction characteristic of the gamma curve does not vary rapidly. The luminance is then corrected using the modified gamma curve.

Abstract: Systems and methods in accordance with embodiments of the present invention are provided to compensate for the “envelope effect” that appears to an end user as a result of the sampling and digital processing of near-Nyquist frequency components of a video information signal. Embodiments of the present invention improve image quality by effectively nullifying gamma correction in areas where the envelope effect exists, enabling the human eye to perceive the displayed signal without the envelope effect.

Abstract: In a video display device of the present invention, a main control unit is equipped with a user interface for varying correction values set to a range correction unit and controls a range correction unit by acquiring the corresponding correction values from a storage unit in accordance with correction level information input by the user interface. The storage unit stores range correction values for the video display unit in correspondence with each piece of the correction level information input by the user interface. Thus, it is possible to correct luminance ranges to suit the user's preference without causing a large luminance reduction.

Abstract: A color correction method is provided. Grey values of three primary colors of an image data are transformed into initial characteristic values in a color space. Three sets of characteristic values of a to-be-corrected apparatus when the apparatus displays the primary colors respectively are measured. The characteristic values of the image data are transformed into a set of adjusted brightness values of the primary colors according to the characteristic values and a color space transformation equation. Gamma curves of the apparatus when displaying the primary colors are measured and modified to generate new grey-value vs. brightness relationships for the primary colors, so as to obtain adjusted grey values of the primary colors corresponding to the adjusted brightness values.

Abstract: The present invention relates to a gamma data generation method of a display device. In the method, gamma data including red gamma data, green gamma data, and blue gamma data is determined. A target luminance and a target color coordinate of a first reference gray are determined. Then, an image is displayed on a display device based on red, green, and blue input image signals for a first reference gray, and a first luminance and a first color coordinate from the image are measured. Then, it is determined whether a coordinate difference between the first color coordinate and the target color coordinate and a luminance difference between the first luminance and the target luminance are in an allowable error range or not.

Abstract: In accordance with at least one embodiment, a first representation of a first gamma curve is stored in a look-up table, a second representation of a second gamma curve is stored in a look-up table, and a video signal is modified in accordance with an interpolation of at least a portion of the first representation of the first gamma curve and at least a portion of the second representation of the second gamma curve. In accordance with at least one embodiment, the at least a portion of the first representation of the first gamma curve is multiplied by a one's complement of a normalized weight factor, the at least a portion of the second representation of the second gamma curve is multiplied by the normalized weight factor, and the results are added together to obtain an output video signal.

Abstract: An organic light emitting display and a driving method thereof, capable of increasing manufacturing yield by widening a range of gamma correction. An exemplary organic light emitting display includes a display region with pixels at crossings of data and scan lines; a gamma correction unit; a gamma correction circuit; a data driver; and a scan driver. The gamma correction unit includes first and second register units for storing first and second gamma correction signals, the second gamma correction signal comprising a corrected first gamma correction signal; a booster unit for correcting the second gamma correction signal to generate a third gamma correction signal; and a multiplexer for selecting the second gamma correction signal or the third gamma correction signal outputted from the booster unit, and for transferring it to the gamma correction circuit.

Abstract: The present disclosure is directed to methods, systems, and apparatuses for modifying streaming video signals to be shown on a visual display. In one embodiment, a method includes receiving a streaming video signal with multiple display components. The method also includes isolating and transmitting the display components to a multiplier according to an associated clock signal for each of the display components. The method further includes fetching correction coefficients from a storage circuit. The correction coefficients correspond to individual display components. The method also includes presenting the correction coefficients to the multiplier along with the display components according to the associated clock signals, and adjusting the display components with the corresponding correction coefficients to form corrected display components of the streaming video signal. The method also includes collecting the adjusted display components into a corrected streaming video signal.

Abstract: Methods for gamut mapping and boosting a color saturation of a color signal having multiple colors and a color value for each color. An example method includes mapping each color from a first to a second color space, adjusting each color in the mapped color signal including boosting a color saturation; determining a maximum color value of the color signal; and, in response to a determining that the maximum color value exceeds a maximum displayable color value, setting the color value of the color having the maximum color value to be equal to the maximum displayable color value and scaling color values of colors not having the maximum color value.

Abstract: This application includes devices and methods for processing multimedia data to generate enhanced multimedia data at a receiver based on encoder assisted pre-processing. In one aspect, processing multimedia data includes identifying at least one pixel intensity range in at least one image of multimedia data, modifying at least a portion of the multimedia data to reduce the pixel intensity range, and encoding the modified multimedia data to form encoded multimedia data.

Abstract: A display driving circuit comprising a video signal transformation circuit, a reference voltage generating circuit, a DAC and an interpolation operational amplifier is provided. The video signal transformation circuit transforms an input video signal into a transformed video signal with a higher bit depth. The transformed video signal comprises an upper n bits data and a lower m bits data, wherein n+m equals a bit depth of the transformed video signal. The reference voltage generating circuit generates reference voltages. The DAC selects a first reference voltage and a second reference voltage to interpolation operational amplifier from the reference voltages according to an upper n bits data of the transformed video signal. The interpolation operational amplifier outputs a driving voltage to display device according to the first reference voltage, the second reference voltage and the lower m bits data of the transformed video 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: An image sensing apparatus including an image sensor having a first area and a second area and a gradation converter for applying a gradation conversion to an image signal is provided with a gradation conversion LUT storage storing at least two kinds of gradation conversion information. The image sensing apparatus is also provided with a gradation conversion information rewriting section for rewriting the gradation conversion information into new gradation conversion information. There can be provided an image sensing apparatus capable of carrying out a precise gradation conversion even in the case that the inflection point between the first area and the second area of the image sensor constantly changes.

Abstract: Display systems that employ input gamma dithering and dynamic backlight control. Embodiments relate to disabling input gamma dithering during periods when there is a change in the scale value by which image data is scaled due to dynamic backlight control. In this manner, input gamma dithering is selectively applied only during those times when data scaling due to dynamic backlight control is constant.

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: A system for dynamic gamma correction of multi-scaled clocks and method therefor are provided, wherein multi-scaled clocks are applied to control the grayscale upon only one set of ramp voltage, so that the linearity of the gamma curve can be adjusted freely or to adjust the gamma correction strategy based on the image content or the user preference.

Abstract: A data processing method of executing nonlinear conversion for pixel data, comprising: a first step of obtaining an amount of statistics corresponding to the number of pixel data having a gradation value in a predetermined range from a plurality of pixel data for displaying a predetermined image; a second step of obtaining a parameter corresponding to the distribution condition of the gradation values of the plurality of pixel data; an adjusting step of adjusting the amount of statistics based on the parameter; and a determining step of determining a conversion characteristic of the nonlinear conversion based on the adjusted amount of statistics.

Abstract: According to one embodiment, a gamma correction circuit including a serial storage unit which serially stores first and second parameter information in a storage area, a first parallel storage unit which parallelly stores the first parameter information in the storage area, a second parallel storage unit, a gamma correction unit which receives a video signal and which performs gamma correction to the video signal based on the first or second parameter information, and a control unit which serially reads the first or second parameter information, parallelly stores the information in the first or second parallel storage units, parallelly reads the first or second parameter information, supplies the information to the gamma correction unit, and performs gamma correction to the video signal based on the first or second parameter information.

Abstract: Apparatus and method for gamma correction are disclosed. An adjustable blending unit is utilized for adjustably blending a linear gamma function with a nonlinear gamma function, thereby resulting in an adjustable gamma curve. The nonlinear gamma function is adjustable by a blending parameter such that distance of the gamma curve to linear gamma curve may be changed.

Abstract: A color conversion method and apparatus for a multi-primary display (MPD) are provided with analyzing an input image to determine a transformation parameter; interpolating at least two look-up tables for color conversion according to the transformation parameter, in order to calculate a look-up table for the input image; and applying the calculated look-up table to the input image to perform the color conversion. Accordingly, it is possible to provide good color reproduction and efficiently use a color gamut of an MPD having color coordinates that are different from those of primaries of an input image.

Abstract: A method of enhancing details in an input image. The input image comprises input pixels, which have input pixel values (IPV) limited to a range (RA). The method comprises average filtering (1) the input pixel values (IPV) to obtain average brightness values (LV). A luminance mask is applied (2) to the average brightness values (LV) to obtain masked values (MV) which are different for average brightness values (LV) in a sub-range (SR) of the range (RA) than for pixels outside the sub-range (SR). The input pixel values (IPV) are detail filtered (3) to obtain detail values (HV) indicative for an amount of detail. A non-linear function (NLF) is applied (5) on the input pixel values (IPV) to obtain for each input pixel value (IPV) a corresponding output pixel value (OPV). A gain of the non-linear function (NLF) is dependent on both the masked value (MV) and detail value (HV) which both are determined for the particular input pixel.

Abstract: A method and apparatus for processing image pixel signals having at least two color components in which at least some of the image pixel signals are classified into a plurality of classifications and transformed by a transform function associated with the classifications.

Abstract: There is a signal processing apparatus, including a gamma correction circuit that performs gamma correction on an input luminance signal and generates an output luminance signal, an output-to-input ratio calculation circuit that calculates a ratio of the output luminance signal to the input luminance signal as an output-to-input ratio of a luminance signal, and a color difference correction circuit that multiplies an input color difference signal by the output-to-input ratio of the luminance signal and generates an output color difference signal. As a result, by correcting the input color difference signal using the output-to-input ratio of the luminance signal, the output color difference signal in which color difference correction has been performed in view of influence of gamma correction can be generated.

Abstract: Average picture level (APL) of a display and, in examples, histogram information is used to dynamically adjust the display contrast, or “gamma”, using an exponential function. APL can also be used for DC transmission adjustment and black/white stretch.

Abstract: An image reproducing apparatus is operative in accordance with multiple display modes. The image reproducing apparatus includes a data reproducing unit that reproduces an image on a display based on high dynamic range image data acquired from an object and stored in memory, and a dynamic range control unit that controls the dynamic range of the image to be reproduced on the display using one of different types of dynamic range control schemes in accordance with one of the display modes.

Abstract: A video bit-stream gamma characteristic correction method and a multipoint control unit in video communication field resolve the gamma distortion problem of video image in the existing multimedia communication. In the method, the receiving end carries out correction once through carrying the gamma characteristic parameter of the transmission end in the video bit-stream; or the multipoint control unit and the receiving end correct gamma distortion of the video image in multiple steps. A multipoint processor (200) of the multipoint control unit includes a gamma characteristic parameter storing module (201), which stores gamma characteristic parameter of the video image transmission end; and a gamma characteristic correction module (202), which is connected to the gamma characteristic parameter storing module and corrects the gamma characteristic of the video image according to the gamma characteristic parameter of the video image transmission end.

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 nonlinearly processed (gamma-corrected) video signal is subjected to three-dimensional signal level correction using three-dimensional correction values and corresponding to a position in a horizontal direction and a vertical direction of a pixel on a display screen of an image display unit and the signal level of the pixel data. Thereby, accurate gamma correction is made possible, and horizontal and vertical area information (grid block) can be disposed in an optimum positional relation according to resolution of the screen.

Abstract: A video signal processing device is a video signal processing device for converting an input first video signal to a second video signal, and inputting to a display panel, the video signal processing device including an input unit for receiving an input of a set value of the second video signal to be converted and output in correspondence to a signal level for each of a plurality of sample points of the signal level of the first video signal; a calculating unit for interpolation calculating the signal level of the second video signal to be converted and output for the signal level between each sample points; and a control unit for transferring a conversion table including a set value of the second video signal for each sample point of the first video signal and an interpolation calculated interpolation value between each sample points to a memory unit; wherein the memory unit converts to the second video signal of a corresponding signal level based on the conversion table according to the signal level of the

Abstract: In a microdisplay TV with dynamic iris control, interpolation is used to undertake 3D gamma adjustment of the display for intermediate brightness levels.

Abstract: A gamma correction apparatus includes a load controlling unit, a non-volatile memory, a volatile memory, a checking unit and a counter. The non-volatile memory stores gamma data and a checking code. The load controlling unit controls an operation of loading the gamma data from the non-volatile memory into the volatile memory. The checking unit receives the checking code and detects whether the gamma data in the volatile memory have an error according to the checking code. The counter accumulates the number of times that the checking unit has detected the error. When the checking unit detects the error, the load controlling unit re-loads the gamma data from the non-volatile memory into the volatile memory.

Abstract: An image processing apparatus according to an embodiment of the present invention includes a correction interval setting unit for setting a correction interval; a correction interval dividing unit for dividing the correction interval into a black side interval and a white side interval; histogram calculating units for calculating a total number of luminance histograms of the black side interval and the white side interval, respectively; gain setting units for setting gains of a ? curve for raising the luminance and a ? curve for lowering the luminance, respectively; gamma curve generating units for generating a gamma curve for raising the luminance and a gamma curve for lowering the luminance, respectively; a gamma curve combining unit for combining the gamma curve for raising the luminance and the gamma curve for lowering the luminance; and a luminance conversion unit for performing the luminance conversion process using the combined gamma curve.

Abstract: A correction characteristic storage portion stores coordinates (Xp,Yp) of a break point P and curve approximation range widths Wa and Wb. A basic broken line coefficient calculation portion calculates a coefficient C1 for a straight line OP and a coefficient C2 for a straight line PP?. An auxiliary straight line coefficient calculation portion obtains division points P and Q at which to divide two line segments AP and PB in the proportion in which a curve approximation range is divided by input data X, and calculates a coefficient C0 for an auxiliary straight line PQ. A range determination portion determines whether the input data lies within the curve approximation range. A coefficient selection portion and a primary expression calculation portion perform either correction based on the basic broken line or correction based on the auxiliary straight line according to the determination.

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 present invention provides a gamma-correction circuit, which is capable to decrease the noise in graphic signal or make the noise not clearly sensible while carrying out gamma-correction on the graphic signals. In the circuit, a high-pass filter is used to decrease the noise in a graphic signal, a gamma-correction section is used for carrying out gamma-correction on the noise suppressed graphic signal, meanwhile a threshold handling section is used for threshold treatment on the high frequency component of the graphic signal to decrease noise, and then the output of the threshold handling section is combined with the gamma-corrected graphic signal through an adder.

Abstract: Disclosed herein is an image signal processor for carrying out conversion into an xvYCC signal by using a photograph film as a material, the image signal processor including: acquisition means for acquiring print film concentration data based on said photograph film; generation means for generating spectral data on an image on a screen previously presumed based on spectral concentration characteristics of colors of a positive film having an image projected on said screen, a spectral distribution of a projection light source, and the print film concentration data; arithmetical operation means for arithmetically operating an XYZ tri-stimulus value corresponding to the spectral data; and conversion means for converting the XYZ tri-stimulus value into the xvYCC signal.

Abstract: A display apparatus includes a display panel; a correcting circuit configured to carry out gamma correction on input gradation data in response to correction data which specifies a shape of a gamma curve to generate output gradation data; and a driving circuit configured to drive the display panel in response to the output gradation data from the correcting circuit. The correcting circuit carries out approximation calculation for the gamma correction based on the input gradation data by using a correction calculation equation whose coefficients are determined based on the correction data, and the correction calculation equation is switched based on a value of the input gradation data and a value of the correction data.

Abstract: A method of processing an image includes traversing pixels of an image in a single pass over the image. An inverting function is applied to the pixels. A recursive filter is applied to the inverted pixel values. The filter has parameters which are derived from previously traversed pixel values of the image. A pixel value is combined with a filter parameter for the pixel to provide a processed pixel value for a processed image.

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: 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: The invention discloses a Gamma transform unit. The Gamma transform unit has a lookup table. The lookup table stores a plurality of difference values corresponding to a plurality of predetermined input values. Each of the difference values substantially equals a difference between an ideal output value and a Gamma function output value, both of which correspond to one of the predetermined input values. After the Gamma transform unit has received an input value, it generates a required Gamma function output value corresponding to the received input value through referring to the lookup table.

Abstract: An image display apparatus of the present invention includes: a picture display unit that forms and displays an optical image based on a video signal; a gamma adjustment image display unit that displays a gamma adjustment image containing input/output characteristics of a signal level of the video signal in the displayed optical image; an adjustment operation unit that changes the displayed input/output characteristics on the image; and an input/output characteristics setting unit that sets input/output characteristics of the signal level of the video signal in accordance with the input/output characteristics changed on the image. The adjustment operation unit includes a point selecting part that selects an adjustment point desired to be changed in the input/output characteristics displayed in the image and a level changing part that is capable of changing both of an input level and an output level of the selected adjustment point.

Abstract: A digital gamma correction circuit includes: a data setting portion for setting set data including a section width W1 and coordinates (Xp,Yp) of a break point P; a coefficient calculation portion for calculating coefficients for straight-line equations representing a broken baseline including a break point and three predetermined approximate line segments for defining a gamma correction broken line approximating an ideal gamma correction curve, the approximate line segments gradually varying in slope in the vicinity of the break point; arithmetic portions for performing arithmetic operations based on the coefficients to subject input data to gamma correction; and a result selection portion for making a suitable selection from among results for the arithmetic operations. Thus, it is possible to obtain a gamma correction broken line approximating an ideal gamma correction curve, and achieve a smooth correction characteristic with a small number of data items.

Abstract: A technique for improving image quality using dynamic gray scale correction, in one example embodiment, includes dynamically computing non-linear gamma curves using histogram data extracted from a current video frame. A gray scale correction is then dynamically applied to each pixel in the current or next video frame as a function of the computed non-linear gamma curves.

Abstract: In a tone conversion apparatus, a decision-processing section sequentially detects a signal level difference between pixels of an image in a predetermined direction thereof by using the image signal having a first number of bits, determines whether the signal level difference remains within a preset signal level difference, and determines a pixel which has the same signal level as that of an immediately preceding pixel that encounters the signal level difference and is consecutive with the immediately preceding pixel. A bit-allocation-processing section may also be utilized.

Abstract: An image display device includes: an image projecting unit for externally performing enlargement projection of a main-image signal; a basic-property selecting unit for selecting a predetermined basic-gamma property from multiple basic-gamma properties of the main-image signal; a correction-property selecting unit for selecting a predetermined correction-gamma property from multiple correction-gamma properties of the main-image signal; a gamma-property calculating unit for calculating a gamma property for each signal level of the main-image signal based on the selected basic-gamma and correction-gamma properties; a gamma correcting unit for subjecting the main-image signal to gamma correction based on the calculated gamma property; an operating unit for outputting a first signal corresponding to a user's basic-gamma-property selection operation, and a second signal corresponding to a user's correction-gamma-property selection operation; and a control unit for controlling each of the selection operations of the

Abstract: In one embodiment the present invention includes a display system for displaying video. The display system includes a backlight layer and an LCD layer. The display system controls the backlight layer and the LCD layer to emulate a cathode ray tube response. This emulation may be accomplished by applying a gamma function to a gamma corrected input signal. In this manner, the effects resulting from the “crushed blacks” phenomenon may be reduced.

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.