Abstract: An image display device detects mutually adjacent bright and dark parts of an image and detects fine bright lines in the image. Bright parts of the image that are not fine bright lines are smoothed if they are adjacent to dark parts. This smoothing scheme improves the visibility of dark features on bright backgrounds without impairing the visibility of fine bright lines on dark backgrounds.

Abstract: An image processing method extends n-bit input image data by ? bits to generate (n+?)-bit source data, where n and ? are positive integers, and smoothes the source data. The maximum difference between gray levels of the unsmoothed source data in an area localized around each pixel is calculated, and a mixing ratio is determined from the maximum difference. The smoothed and unsmoothed source data are mixed according to the mixing ratio to generate output image data. In areas with gradually changing gray levels, the output image data are weighted toward the smoothed source data, mitigating image degradation due to quantization and gamma correction. In areas with sharp edges, the output image data are weighted toward the unsmoothed source data, preventing a loss of edge sharpness.

Abstract: A field-sequential display apparatus having a light source that emits light of different colors in different subframes of an image controls the spectral distribution of the light emitted in each subframe according to characteristics of the input image data, or to ambient conditions or other user-specified conditions. The input image data are processed so that image colors are displayed correctly despite changes in the spectral distribution of the light-source colors. This scheme enables the gamut of reproducible colors to be altered from frame to frame to provide an appropriate balance between brightness and color saturation in each frame, and to compensate for ambient lighting conditions.

Abstract: A color demodualation device having an AD converter, a phase signal generator, a burst data generator and a multiplier. The AD converter produces digital samples of chrominance signal at a frequency four times a color subcarrier frequency, and the phase signal generator generating a phase signal for identifying phases of a burst signal and color subcarrier signals modulated by respective B-Y and R-Y signals. The burst data generator produce burst data corresponding to the burst signals modulated by respective B-Y and R-Y signals. The burst respective color subcarrier signals according to the phase signal. The multiplier produces products of the burst data and the digital samples of the chrominance signal, from which digital samples of the respective R-Y and B-Y signals are produced.

Abstract: Missing-pixel interpolation data are obtained such that the mean value of a plurality of pixels constituting a group of pixels including a missing pixel is equal to the mean value of a plurality of pixels constituting a group of pixels not including the missing pixel. For example, missing-pixel interpolation data are obtained by (1) obtaining a sum (SL) of the values of pixels other than the missing pixel (L) in the k pixels constituting the group (LC) of pixels including the missing pixel, (2) obtaining a sum (SA) of the values of k pixels constituting a group (NA) of pixels not including the missing pixel, and (3) taking the difference between these sums. This makes it possible to reduce interpolation error when a highly periodic image with missing pixels is interpolated.

Abstract: A color conversion apparatus receives red-green-blue color data, calculates characteristic information and first hue region data from the color data, adjusts the first hue region data according to the characteristic information to obtain second to N-th hue region data, N being an integer equal to or greater than three, generates matrix coefficients for the second to N-th hue region data, and performs a matrix operation on the second to N-th hue region data to obtain color data with four or more color components. Color data with three primary components are thereby converted to color data with four or more primary components by simple calculations, without using a large amount of memory space.

Abstract: An image display device includes a smoothing unit that filters the image data to be displayed. According to one aspect of the invention, only bright parts of the image that are adjacent to dark parts are smoothed, thereby improving the sharpness of dark dots and lines displayed on a bright background. According to another aspect, different primary colors are smoothed with different characteristics, enabling unwanted colored tinges to be removed from the edges of white areas. According to still another aspect, smoothing moves the luminance centroids of all primary colors in a direction in which the display screen is scanned, to reduce ringing effects without needless loss of edge sharpness.

Abstract: In a period from temporal storage of a video signal to reading and displaying of the video signal, an average value 121 of the brightness levels obtained from a video signal before the video signal is stored in a storage means 3 and a predetermined target value 122 are used to perform a calculation by using a proportionality term and an integration term so that a quantity of limited electric currents is obtained. Moreover, the quantity of limited electric currents is provided with a non-response region or a hysteresis characteristic.

Abstract: A tone step detector detects whether the tone of n-bit input image data varies gradually, and generates a tone processing control signal indicating that a tone step is contained. A bit shifter bit-shifts the n-bit input image data to the left by ? bits, to generate (n+?)-bit image data. A tone processor smoothes the image data of the (n+?)-bit image data generated by the bit shifter, in the region where the tone processing control signal indicates that a tone step is contained, to generate (n+?)-bit image data having been smoothed in the above-mentioned region. Because of the selective smoothing, degradation in the image quality due to quantization is reduced even when an analog image signal whose tone varies gradually is input.

Abstract: A coding circuit codes present image data of a pixel which is received as raster data and a delay circuit stores a coded image data for one frame period and outputs one-frame preceding image data of the pixel in accordance with an input of the coded image data. First and second decoder circuits decode coded image data and one-frame preceding coded image data, respectively, a variation-amount calculation circuit calculates variation-amount data of both decoded image date, and an one-frame preceding image reproduction circuit reproduces one-frame preceding reproduced image data. An image date correction circuit generates corrected present image data on the basis of the present image data and the one-frame preceding reproduced image data.

Abstract: A pixel interpolation circuit according to this invention includes a plurality of interpolation circuits each calculating interpolation candidate data of a interpolation pixel and test interpolation data of a plurality of pixels neighboring the interpolation pixel using different interpolation methods, a determining circuit for selecting one of the interpolation circuits based on a difference between the test interpolation data and actual pixel data, and an output circuit for outputting the interpolation candidate data calculated by the selected interpolation circuit as the interpolation pixel data.

Abstract: An apparatus includes an edge width detection circuit (1) which detects an edge portion of image data (DI) and outputs an edge width (W) of the detected edge portion, a ratio control amount generation circuit (2) which generates a ratio control amount (ZC) in accordance with the edge width (W), a ratio generation circuit (3) which generates a conversion ratio (Z) in accordance with the ratio control amount (ZC), and a pixel number conversion circuit (4) which performs a conversion of pixel number of the image data (DI) using the conversion ratio (Z), thereby enhancing sharpness of the edge portion in proper quantities.

Abstract: In order to reduce the total capacity of a ROM used for adjustment of the black level and the white level of a digitized luminance signal for a television receiver, for example, a comparator compares the input luminance signal with a predetermined threshold value, a NOT gate inverts the input luminance signal, a first switching unit selects the input luminance signal or the output of the NOT gate, a ROM outputs an adjustment characteristic signal responsive to the output of the first switching unit, a multiplier multiplies the output of the ROM by a weighting signal and outputs the result of the multiplication as an adjustment value, a subtractor subtracts the adjustment value from the input luminance signal, an adder adds the adjustment value to the input luminance signal, and a second switching unit selects the output of the subtractor or the output of the adder.

Abstract: An apparatus and method are disclosed for displaying an image having high frequency components. The image is displayed on a display device that includes a plurality of display elements arranged in both horizontal and vertical directions. The display elements represent colors, such as red, green and blue. A pixel data generator generates for each display element first pixel data corresponding to the luminance levels of red, green and blue colors in the image. A smoothing filter eliminates false colors in the image by applying weighting coefficients to the first pixel data to modify the luminance levels of the first pixel data, thereby producing second pixel data having second color element data corresponding to luminance levels of the respective colors. Each display element of the display is driven in accordance with the second color element data.

Abstract: An image display device includes a smoothing unit that filters the image data to be displayed. According to one aspect of the invention, only bright parts of the image that are adjacent to dark parts are smoothed, thereby improving the sharpness of dark dots and lines displayed on a bright background. According to another aspect, different primary colors are smoothed with different characteristics, enabling unwanted colored tinges to be removed from the edges of white areas. According to still another aspect, smoothing moves the luminance centroids of all primary colors in a direction in which the display screen is scanned, to reduce ringing effects without needless loss of edge sharpness.

Abstract: The frequency of the dot clock in an image display device is adjusted by calculating a first image characteristic from the differences between adjacent picture elements, varying the phase of the dot clock, determining whether the frequency of the dot clock is correct from the way the first image characteristic varies according to the phase of the dot clock, and changing the frequency if it is incorrect. The first image characteristic is, for example, the maximum difference, the histogram distribution of the differences, or a ratio calculated from the histogram. The phase of the dot clock may be adjusted according to a second image characteristic, such as the difference between a single pair of pixel values, which is also measured over a range of dot-clock phase settings.

Abstract: A method of changing edge sharpness of an input image being formed from input pixels having intensity levels, the method including detecting pixel-to-pixel variations in the intensity levels in at least one direction in the input image, thereby generating local pixel variation patterns; determining a localized zoom ratio based on the local pixel variation patterns; controlling edge sharpness by changing the localized zoom ratio setting interpolation points with spacing between the interpolation points varying based on the localized zoom ratio and a basic zoom ratio; and generating output pixels from the input pixel by interpolation at the interpolating points.

Abstract: An image display device includes a smoothing unit that filters the image data to be displayed. According to one aspect of the invention, only bright parts of the image that are adjacent to dark parts are smoothed, thereby improving the sharpness of dark dots and lines displayed on a bright background. According to another aspect, different primary colors are smoothed with different characteristics, enabling unwanted colored tinges to be removed from the edges of white areas. According to still another aspect, smoothing moves the luminance centroids of all primary colors in a direction in which the display screen is scanned, to reduce ringing effects without needless loss of edge sharpness.

Abstract: An image signal generating apparatus, method, program and information storage medium for causing display units to display individual images. The apparatus includes a signal generator sequentially generating an image signal for each frame, an indexer adding an index signal, and an output circuit transmitting the image signal. The apparatus also includes a window controller which causes the plurality of display units to display a window under control of an application software, holds display position information of the window, and controls input and output of data using the window. When the index signal added to the image signal for each frame is changed to an updated index signal, the window controller transforms the display position information of the window in accordance with the updated index signal.

Abstract: An image signal generating apparatus, method, program and storage medium for causing display units to display individual images. The apparatus includes a signal generator, an indexer adding an index signal, and a pointer controller controlling addition or non-addition of a pointer signal. The apparatus also includes an output circuit transmitting the image signal, thereby causing the display unit having identification data corresponding to the index signal to display an image, and a central controller controlling in such a way that the pointer signal is not added to the image signal during at least one frame period from a first time point that is at least one frame period previous to a second time point at which the display unit for displaying the one page image based on a received image signal is changed by changing the index signal added to the image signal for each frame.