Abstract: Projection systems and/or methods for efficient use of light by recycling a portion of the light energy for future use are disclosed. In one embodiment, a projection display system is disclosed comprising a light source; an integrating rod that receives light from said light source at a proximal end that comprise a reflective surface which may reflecting/recycle light down said integrating rod; of reflecting light down said integrating rod; a relay optical system, said relay optical system further comprising optical elements that are capable of moving the focal plane of the projector display system; and a modulator comprising at least one moveable mirror that reflects light received from the integrating rod in either a projection direction or a light recycling direction.

Abstract: A first tone correction unit generates a second image signal by applying, to a first image signal, first tone correction processing conforming to a first tone correction characteristic. A second tone correction unit generates a fourth image signal by applying, to a third image signal, second tone correction processing conforming to a second tone correction characteristic. A generation unit generates a fifth image signal by compositing a luminance component of the second image signal and a color difference component of the fourth image signal. A first tone conversion unit generates a sixth image signal by applying, to the fifth image signal, first tone conversion processing conforming to a non-linear first tone conversion characteristic. The second tone correction characteristic is determined based on the first tone correction characteristic and a non-linear second tone conversion characteristic.

Abstract: A display apparatus includes a sight line detection unit that detects a line of sight of a user by analyzing user video information, an enhancement processing unit that detects an intersection point of the line of sight of the user detected by the sight line detection unit and a video display surface of a monitor as an attention point, which is a point on which the user focuses attention, and performs enhancement processing for the monitor by setting a higher gain amount in stages from a position of a longer distance from the attention point toward a position of a smaller distance, and a display video output control unit that outputs video via the monitor based on the gain amount set by the enhancement processing unit and display video information whose input is received by a display video information input unit.

Abstract: Local contrast enhancement comprises obtaining a first frame as a reference frame and a second frame as a current frame. The reference frame is partitioned into a plurality of reference regions, and a first color mapping function is derived for at least one of the reference regions in the reference frame according to the corresponding color distribution. The first color mapping function comprises, for at least one of a predetermined set of colors, a first source color value and a first contrast-enhanced color value. The current frame is partitioned into a plurality of regions, and a second color mapping function is derived for at least one of the regions in the current frame according to the first color mapping functions of at least two of the reference regions in the reference frame. The second color mapping function is applied to generate a contrast-enhanced frame.

Abstract: A method for displaying a video which is dithered using related masks and a video display apparatus applying the same, the video display apparatus dithering a video signal using a first mask, performing color-processing with respect to the video signal, and dithering the color-processed video signal using a second mask which is related to the first mask. Accordingly, dithering is performed using related masks, thus preventing poor gradation of video signal.

Abstract: A method, apparatus and system for assessing color characterization quality includes a characterization unit configured for determining at least one of a forward and inverse transform from a first set of device dependent input color values and measured output display values of the first set of device dependent input color values on the display and transforming a second set of device dependent input color values using the determined at least one of a forward and inverse transform to provide an intermediate set of device dependent input color values. The method, apparatus and system further includes a verification unit for performing at least one of a forward transform quality evaluation and an inverse transform quality evaluation.

Abstract: A display apparatus includes a sight line detection unit that detects a line of sight of a user by analyzing user video information, an enhancement processing unit that detects an intersection point of the line of sight of the user detected by the sight line detection unit and a video display surface of a monitor as an attention point, which is a point on which the user focuses attention, and performs enhancement processing for the monitor by setting a higher gain amount in stages from a position of a longer distance from the attention point toward a position of a smaller distance, and a display video output control unit that outputs video via the monitor based on the gain amount set by the enhancement processing unit and display video information whose input is received by a display video information input unit.

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: The present invention provides a device and an image adjustment method by simultaneously adjusting the luminance and the chrominance of an image. The device comprises a luminance analysis device, a contrast adjusting device, a luminance adjusting device, a chrominance compensation device and a luminance gain adjusting device. The method comprises steps of: generating a maximum input luminance signal, an average input luminance signal and a minimum input luminance signal according to an input luminance signal; generating a contrast value according to at least one of the maximum input luminance signal and the average input luminance signal; generating an input luminance offset according to the input luminance signal and the minimum input luminance signal; generating an output chrominance signal according to the contrast value and an input chrominance signal; and generating an output luminance signal according to the input luminance offset and the contrast value.

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: An image processing apparatus includes a non-linear smoother for smoothing input video data with an edge component thereof preserved, and outputting smoothed video data, a subtractor for subtracting the smoothed video data from the input video data and outputting high-frequency component video data not containing the edge component, an outline extractor for extracting the edge component from the smoothed video data and outputting edge component video data, a first amplifier for varying a signal level of the edge component video data, a second amplifier for varying a signal level of the high-frequency component video data not containing the edge component, and an adder for adding video data output from the first amplifier and video data output from the second amplifier to one of the smoothed video data and the input video data.

Abstract: A video signal converter has a target pixel setting unit which sets up a position of a target pixel of an input video signal, a position parameter feeding unit which supplies a position parameter depending on the position of the target pixel set by the target pixel setting unit, and a characteristic amount calculating unit which calculates a characteristic amount of the input video 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: A display device comprises a data input unit configured to convert an image signal to a color signal. The display device also comprises a brightness control unit operationally coupled to the data input unit, configured to extract a brightness level associated with the color signal, to subdivide the brightness level associated with the color signal, and to apply different voltages according to brightness level subdivisions to control brightness of the color signal. The display device also comprises a display unit configured to display the color signal according to controlled brightness. The brightness level may comprise gray levels of a ? curve. The color signal may comprise one of YUV or RGB signals.

Abstract: The present invention relates to a method and a device for adaptive color correction by weighting procedure according to the pixel luminance so as to adjust the pixel chrominance. The present invention prevents color noise occurring in the dark pictures. The method for adaptive color correction, comprises steps of: providing a luminance value of a pixel: determining a weighting value corresponding to said luminance value of said pixel, wherein said weighting value substantially increases when said luminance value increases; and adjusting chrominance of said pixel according to said weighting value.

Abstract: Methods and systems for adjusting color-saturation contrast of the video signal. Statistical information based on chrominance or luminance measures is analyzed to derive a gain function. The gain function is also determined according to the detection result of an exceptional situation during statistical analysis. The gain function is applied to the video signal to modify the amplitude of the chrominance signal.

Abstract: A color saturation control unit and method for increasing the color saturation of an image is presented. A scaled saturation enhancement factor calculation unit generates a scaled saturation enhancement factor using a base saturation enhancement factor. A multiplier generates a saturation enhanced U chrominance value and a saturation enhanced V chrominance for the current pixel by multiplying the scaled saturation enhancement factor multiplied with the current chrominance values. The ratio of the saturation enhanced chrominance values should be equal to the ratio of the current chrominance values. A lookup table contains tabled saturation enhancement factors that can be used as the scaled saturation enhancement factor when the base saturation enhancement factor would cause the saturation enhanced U chrominance value or the saturation enhanced V chrominance value to exceed a valid range of chrominance values.

Abstract: The present invention discloses a method and a device for image contrast enhancement by taking the contribution of image chroma into account so as to define the luminance signal with the chroma weighted value. The new defined luminance signal can be applied towards expressing the image's parameters of original luminance signal and compensated chroma signal, through means of a statistic histogram extraction and the ratio relationship between before and after luminance curve process. Therefore, pictures can be provided with better saturation for satisfying the viewer's requirements, as observed from the process of the present invention.

Abstract: The invention provides an apparatus for dynamically adjusting the saturation of an image signal consisting of a plurality of pixels. The apparatus includes a first transformation module, an operation module, a gain module, an adjustment module and a second transformation module. The first transformation module transforms the pixels of the image signal into a plurality of intermediate signals, where each of the intermediate signals has a respective saturation value. The intermediate signals are adjusted in accordance with a gain signal determined by a histogram relative to the saturation distribution of the intermediate signals. The adjusted intermediate signals are transformed back into the pixels of the image signal, thereby the saturation of the image signal is adjusted.

Abstract: A video decoder (10) for receiving an input video signal and producing output signals for a digital display (12), and involving automatic gain control (AGC) functions (20, 28), is disclosed. For each of the front-end and back-end AGC functions (20, 28), the AGC gain value applied is modified according to measurements of several attributes of the video signal, such as sync height, color burst amplitude, composite signal peak amplitude, and luma signal peak amplitude. The measurements are made, and the AGC gains are modified, on a frame-by-frame basis. Preferably, the AGC is modified using the one of the signal attributes that indicates the lowest gain. The back-end AGC function (28) modifies its gain to unity if the front-end AGC function (20) selected the luma signal peak amplitude for modifying its gain. A method for adjusting the rate of change of the AGC gain is also disclosed, in which gain increases are delayed and slowed following an AGC gain decrease because of an image-dependent signal attribute.

Abstract: The present invention discloses a method and a device for independent color management by using a look-up table (LUT) so as to adjust the color saturation of a single color independently. The method comprises steps of: receiving a color signal of an input pixel; determining color flags and initial saturation values from the color signal by using a look-up table (LUT); obtaining user-controlled color gains according to the color flags; multiplying each of the initial saturation values with one of the corresponding user controlled color gains so as to output an adjusted saturation value; determining a final gain from each the adjusted saturation value by bilinear interpolation according lower-bits of the color signal; and obtaining a new color signal according to the final gain and the color signal.

Abstract: An analog-to-digital converter converts a video signal into a digital video signal consisting of N bits and outputs the converted signal. A correction value memory stores correction data consisting of M bits which is used to correct the difference in luminance between display pixels on a display. A multiplier multiplies the video signal consisting of N bits output from the analog-to-digital converter by the correction data consisting of M bits stored in the correction value memory, and outputs a video signal consisting of L bits with which the difference in luminance between display pixels on the display is corrected.

Abstract: A projection-type display apparatus for projecting an image onto a screen includes a light source, a signal processing unit for processing an input image signal to output a first image signal representing first primary-color information R1, G1, and B1 representing values of red, green, and blue components of an image to be projected, a signal conversion unit for converting the first image signal into a second image signal representing a coefficient M which depends on luminance of the image to be projected defined by the first primary-color information R1, G1, and B1, and into a third image signal representing second primary-color information R2=R1/M, G2=G1/M, and B2=B1/M.

Abstract: An apparatus for and a method of continuously adjusting a brightness and a contrast of a video display. An analog video signal is converted to provide digital luminance (Y) signals and amplitudes of the digital Y signals are adjusted based on determining whether the digital Y signals of a frame have amplitudes corresponding to one or more of four regions of digital values. The four regions include a highest region, a second highest region, a lowest region and a second lowest region. Contrast is adjusted based on whether digital Y values of the frame are included for the highest region and/or the second highest region and brightness is adjusted based on whether digital Y values are included for the lowest region and/or the second lowest region.

Abstract: Disclosed are methods and systems for automatic gain control (AGC) in circuits. The disclosed methods and systems provide accurate and rapidly converging automatic gain control suited for video applications. According to disclosed preferred embodiments of the invention, a signal amplitude controlling method is responsive to gain underflow or overflow. A new fine gain control value is extrapolated and a new coarse gain control value is determined. The new fine gain and new coarse gain control values are applied to the signal to produce an output signal within a pre-selected output amplitude range.

Abstract: A brightness limitation system is employed in a television circuit to prevent the black reference voltage level and the video signal from entering a minimum signal clipping zone, to provide precise correction signal, limiting the brightness, to maintain a constant black reference voltage level, and maintain a video signal with dynamic amplitude. The brightness limitation circuit detects a minimum signal level amongst the black reference signals from each color channel and compares the minimum signal with a fixed voltage level to generate a brightness feedback signal. The brightness feedback signal is then used to modify the black reference signal level for each color channel.

Abstract: The present invention has an object to provide a gradation correcting apparatus for correcting the gradation of the white side of a video luminance signal. The gradation correcting apparatus is provided with a maximum value detector 101 for detecting a maximum value of a luminance signal S101, a white comparator 102 for comparing the luminance signal S101, a maximum luminance value S111 detected by the maximum value detector 101, and a first white threshold value S103, a white linear converter 103 for performing linear conversion on the luminance signal S101 on the basis of the maximum luminance value S111, the first white threshold value S103, and a second white threshold value S104, and a white controller 104 for correcting the luminance signal S101 on the basis of the result of the comparison in the white comparator 102, the output of the white linear converter 103, and the second white threshold value S104.

Abstract: A method for dynamically adjusting video brightness performs histogram equalization on a video YUV brightness/color signal to generate an equalization brightness curve. The brightness of each pixel is compared with every pixel of the video frame before and after histogram equalization to generate a comparison difference value. The brightness of the pixel is adjusted so that the brightness difference after adjustment won't be larger than three times of the comparison difference value and won't be smaller than a fourth of the comparison difference value. The brightness of each pixel before and after histogram equalization is compared, one by one, to generate a brightness difference value. The brightness difference value is adjusted so that the brightness difference after adjustment won't be larger than a largest brightness value and won't be smaller than a smallest brightness value. The brightness of each video frame can be properly adjusted to accomplish clearer displaying effect.

Abstract: To provide an image processing system, projector, information storage medium and black and white extension processing method which can improve the quality of image when at least one of white extension and black extension is performed to video signals, a extension degree setting section is controlled by using a control section to change a degree of extension only when a change-over of scenes occurs, and luminance values of R-signals, G-signals and B-signals are extended toward one of white and black sides with the degree of extension set by the extension degree setting section by using extending sections and a luminance changing section.

Abstract: A method of increasing image dynamic range by breaking each pixel into two or more time displaced samples that are presented to the display in synchronization with appropriate illumination.

Abstract: The present invention relates to controlling contrast in at least part of a picture. The contrast control is performed by reducing the saturation (2–4) of the picture during contrast increase (1).

Abstract: The present invention provides a gradation correction device which can perform gradation correction using digital feedback processing, and furthermore, can control the digital feedback processing with high accuracy. The gradation correction device is provided with a correction gain adjustable amount generation circuit (103) and a correction gain generation circuit (104), and the correction gain adjustable amount generation circuit (103) obtains a correction gain adjustable amount which is non-linear in relation to a difference S between a reference luminance level Yb1 and a maximum luminance level, and greater gamma correction is carried out as the value of the difference is larger.

Abstract: An ACC system includes a controllable amplifier having an input coupled to receive a chroma input signal and an output for providing an chroma output signal of controllable amplitude. A first feedback path, including a cascade connection of means for providing a signal representative of a measured burst amplitude, means for providing an error signal representative of the difference between a desired burst amplitude and the measured burst amplitude, and an integrator, is coupled between the output of the controllable amplifier and a gain control input of the controllable amplifier.

Abstract: A drive circuit of an LCD is disclosed, by which no image signal having a voltage level over the dynamic range of the video amplifier, and thus erroneous operation of the video amplifier is prevented, thereby supplying normal image signals to the LCD. The drive circuit comprises a clip circuit for clipping the amplitude range of the voltage of a picture signal input from an input terminal; a polarity inversion circuit for receiving the picture signal whose amplitude range was clipped by the clip circuit, and for converting the picture signal so that an inverted signal and a non-inverted signal are alternately assigned to each dot; and a video amplifier for amplifying the voltage level of the converted picture signal by a predetermined amplification degree.

Abstract: In order to generate a risk index of stress symptoms triggered by flashing lights on a scan type video display screen, a video signal processor is provided which operates such as to implement temporal filtering and spatial filtering on a video signal applied thereto every field and detect low temporal frequency components while excluding effects due to high spatial frequencies. A risk index generator receives the low frequency components from the video signal processor and determines the risk index based thereon.

Abstract: A method of increasing image dynamic range by breaking each pixel into two or more time displaced samples that are presented to the display in synchronization with appropriate illumination.

Abstract: An offset level detection method for auto color gain control of analog video signals, which is used to find an optimal offset level for determining the input of the auto color gain control. The method includes at least the following steps: First, a lower limit of the min of analog video signals is determined. The position of the lower limit of the min is set as a first min. An upper limit of the min is searched backwards from the first min. The position of the upper limit of the min is set as a second min. Finally, the first min and the second min are averaged to obtain an optimal offset level.

Abstract: A device and a method for controlling a video signal in a video display device controls a magnitude of an RGB video signal by controlling RGB gain values based on RGB count values controlled through external key inputs.

Abstract: An appropriate correction quantity is obtained for a video luminance signal on an individual video basis with a characteristic value, like the maximum or average value, of the luminance signal taken into account, thereby performing gray scale correction more effectively.

Abstract: A apparatus and apparatus for compensating for video insertion loss due to transmission over long twisted pair cable lines is presented. Transmission of video over twisted pair cable is advantageous because of its superior cost advantage over coaxial cable. However, twisted pair cables have significant loss characteristics at the higher frequencies (i.e., broadband) compared to coaxial cables. At a transmitter station, the video signal is amplified in the high frequency region for possible skin effect losses thereby brute forcing the high frequency components to the receiving station. At the receiver station, the video signal is further compensated for diffusion line and skin effect losses. The total skin effect compensation applied in both the transmitter and receiver stations is such that the square root of frequency characteristics of skin effect losses is compensated for.

Abstract: A method (400) and a system (100) for providing video signals to video displays includes the steps of receiving at least one input video signal (150), dithering the non-uniformity color correction (445), applying the non-uniformity color correction to the input video signal to generate a color corrected video signal (450), and increasing a frame rate of the color corrected video signal (120). Gamma correction (125) can be applied to the color correction. Generating a dithered non-uniformity color correction can include selecting from a data storage (115) a plurality of RGB correction matrices (300), measuring at least one brightness level of the input video signal, selecting for the picture level correction a first RGB correction matrix if the brightness is within a first range of values (425), a second RGB correction matrix if the brightness is within a second range of values (435), and interpolating (440) the plurality of RGB correction matrices if the brightness is within a third range of values.

Abstract: A video signal processing circuit for making adjustments of a brightness, a contrast, a hue, and the like of a color video signal by a simple circuit construction. Input video signals which are supplied as 3-primary color signals or luminance and color difference signals are converted to the luminance and color difference signals or the 3-primary color signals and processed to effect adjustments of a picture displaying form, and the adjusted signals are inversely converted subsequently.

Abstract: An apparatus for transmitting over optical cables a red image signal, a green image signal, and a blue image signal output from a personal computer, a clock signal indicative of the starting points of data frames of the image signals, an enable signal indicative of scan and blank periods of the image signals, a vertical synchronization signal and a horizontal synchronization signal. The apparatus includes a reference signal generator, a parallel-to-serial converter and a light signal generator. The reference signal generator generates a reference signal having predetermined data when the blank period starts in accordance with the enable signal. The parallel-to-serial converter converts the reference signal corresponding to the blank period and the image signals corresponding to the scan periods into serial signals.

Abstract: A video signal processing apparatus capable of improving signal level while reducing noise component no matter a video signal of what illuminance is input is provided, which apparatus includes a video signal amplifying circuit amplifying an input video signal and outputting a video signal of a predetermined image size in accordance with a gain control coefficient, a frame addition circuit connected to the video signal amplifying circuit for adding outputs of the video signal amplifying circuit by a predetermined number of frames, a first signal level detecting circuit connected to the video signal amplifying circuit and calculating the gain control coefficient and a multiplication coefficient in accordance with an output of the video signal amplifying circuit, and a first multiplier connected to the frame addition circuit and the first signal level detecting circuit and receiving as inputs an output of the frame addition circuit and the multiplication coefficient.

Abstract: The present invention relates to a chrominance signal processing apparatus and method for providing optimal color processing according to the hue of the color image data. Red, green and blue signals are input to a chroma composition ratio determination circuit that generates and outputs the RGB color composition ratio (&agr;:&bgr;:&ggr;). A chroma suppression luminance signal generating circuit then generates a chroma suppression luminance signal Ya based on the RGB signals and the color composition ratio. A chroma suppression gain determination circuit outputs the gain for the chroma suppression luminance signal based on a table in which output gain setting values corresponding to the chroma suppression luminance signals are recorded. Multipliers then multiply input color-difference signals Cr, Cb by the gain and output a suppressed color-difference signals (Cr×G, Cb×G) according to the color composition ratio (&agr;:&bgr;:&ggr;).

Abstract: In a video stabilizing circuit for a display apparatus, the clamp levels of R, G and B chromatic signals are controlled by feeding back the output currents of respective R, G and B terminals so that real time responses can be made, as against the fluctuations of video output load, thereby obtaining high brightness displays. The circuit according to the present invention is characterized in that output currents of R, G and B terminals are fed back from video output sections to clamp level control sections. The potential of a cut-off control terminal of the video pre-amplifier is then varied in such a manner that, if the beam current sensed by the clamp level control section is large, the bias voltage of the chromatic signals is made small. If the beam current sensed by the clamp level control section is small, the bias voltage of the chromatic signals is made large. Therefore, during a high brightness display, fluctuations in the brightness of the high beams and low beams is reduced and display is improved.

Abstract: A method for automatic partial correction of the color contrast and intensity of color images. The images are processed in a manner similar to that by which the visual system processes signals related to color vision, to achieve better color contrast and to enhance achromatic contrast intensity for both still and video images.

Abstract: In an S-video signal processor, the luminance signal is amplified and adjusted over selected frequency ranges using a parallel signal for shaping the S-video signal response and permitting the S-video signal to be transmitted over exceptionally long transmission lines while providing a quality picture. In separate channels, chrominance and luminance signals are amplified and impedance matched. A luminance band pass filter permits manual adjustments to a lower range of video signal frequencies and thus changes to white level picture information. One version of the S-video signal processor includes a positive feedback network which permits user adjustments in an upper video signal frequency range having picture super detail information for providing a picture of high resolution and thus pleasing to the user. In a second version a compensation amplifier is used to alter the frequency response of the luminance signal.

Abstract: An offset level detection method for auto color gain control of analog video signals, which is used to find an optimal offset level for determining the input of the auto color gain control. The method includes at least the following steps: First, a lower limit of the min of analog video signals is determined. The position of the lower limit of the min is set as a first min. An upper limit of the min is searched backwards from the first min. The position of the upper limit of the min is set as a second min. Finally, the first min and the second min are averaged to obtain an optimal offset level.

Abstract: Red color saturation is increased and red color with higher purity can be reproduced by composing: a red color detection circuit 1 for detecting a red color signal having higher purity by inputting color differential signals (R-Y) and (B-Y) modulated by color subcarrier, subtracting the absolute value of the (B-Y) signal from the positive polarity component of the (R-Y) signal and removing the negative part of the subtracted signal; Y signal compensation block including: first gain controller 50b for controlling the output signal amplitude of red color detection circuit 1 and a subtracter 50a for subtracting the output signal of first gain controller 50b from a luminance signal Y; an (R-Y) signal compensation block including: second gain controller 51b for controlling the output signal amplitude of red color detection circuit 1 and an adder 51a for adding the output signal of second gain controller 51b and the input (R-Y) signal; and a (B-Y) signal compensation block including: third gain controller 52b for c