Abstract: The invention relates to a display device for rendering gray tone images on a monitor controlled by s electron rays. The display device includes a correction unit for generating s output image signals As composed of gray tone values forming part of a set K of correction gray tones from an image signal. The image signal is composed of gray tone values forming part of a set M of original gray tones, and the s output image signals As, after a D/A conversion, are fed each to one electron ray for a brightness-corrected rendering of a gray tone in one pixel of the monitor for the purpose of adapting the brightness distribution of the monitor to the optimum perceptional brightness distribution.

Abstract: A method and apparatus for controlling tint in a digital color display system capable of efficiently performing tint control of displayed colors. The tint control method is executed according to the following: (1) when the maximum and the minimum among R, G, B are the maximum gray scale value and the minimum gray scale value respectively, a step of transforming the input color into a color of a different tint based on a use defined maximum transformation value and a transformation direction; (2) when the maximum and the minimum among R, G, B are Dmax and Dmin respectively, a step of transforming the input color into a color of a different tint based on a smaller transformation value and the same transformation direction; and (3) when all values R, G, B are equal, a step of not transforming the input color in accordance with any input set value.

Abstract: A method and apparatus for digitally driving an addressable pixel display by modulating each pixel e.g., on or off, in short time pulses. A preferred embodiment responds to N-bit pixel words derived from a source digital file at a rate F1 for producing M-bit data streams at a rate F2 where N>M and F1<F2. Each data stream is preferably produced by an oversampling data modulator employing a delta-sigma implementation.

Abstract: In a display driving method, noise is added (NG, AD) to a video signal before the video signal is subjected to a dithering operation (DC).

Abstract: An apparatus for creating an ICC profile in a simple manner without using a specialized measuring instrument. A display control unit reads out a dot pattern image from a pattern image data holding unit and a grayscale pattern image containing a plurality of grayscale patches of gradually varying gray scale from a grayscale image data holding unit, and presents the thus readout images for display on a display device. A user selects the grayscale patch having brightness closest to the brightness of the dot pattern image by operating a selection unit. Based on the selection, a gamma coefficient value is calculated by a gamma coefficient value calculation unit, and based on this gamma coefficient value, a profile creation unit modifies the ICC profile held in a common information holding unit and thus creates a customized ICC profile.

Abstract: Each of a plurality of input images is smoothed. A plurality of smoothed images different from each other in the degree of smoothing thus results. Each of first and second synthesizers calculate an edge intensity based on an intermediate synthesized image generated from at least one smoothed image and having a relatively large degree of smoothing and another smoothed image having a relatively small degree of smoothing, and synthesizes the intermediate synthesized image and the smoothed image based on the edge intensity, thereby generating a synthesized smoothed image. A second synthesized smoothed image generated by the second synthesizer is output as a final synthesized smoothed image representing an illumination component, and is then used as a coefficient for converting a pixel value.

Abstract: Digital pictures are taken by a digital camera. The digital camera provides picture data with a large dynamic range of, for example, 10 bit. Data processing and display devices operate with 8 bit only, i.e do not take advantage of the high dynamic range of the camera This is important in traffic monitoring installations, where, on one hand, the driver in a relatively dark passenger compartment of a vehicle and, on the other hand, the bright license plate have to be recognized to provide evidence in court. For this reason, a dark picture and a bright picture are derived from the picture data provided by the camera. This is done by reading, on one hand, the eight least significant digits and, on the other hand, the eight most significant digits of the camera output to provide the dark and bright pictures, respectively. The dark and bright pictures thus obtained are balanced against color, gray, contrast or brightness values of histograms derived from previous pictures.

Abstract: An image display apparatus which displays images, suppressing the occurrence of the moving image false edge. The image display apparatus selects a signal level among a plurality of signal levels in accordance with a motion amount of an input image signal, where each signal level is expressed by an arbitrary combination of 0, W1, W2, . . . and WN and luminance weights W1, W2, . . . and WN are assigned to subfields.

Abstract: A method and apparatus for digitally driving an addressable pixel display by modulating each pixel e.g., on or off, in short time pulses. A preferred embodiment responds to N-bit pixel words derived from a source digital file at a rate F1 for producing M-bit data streams at a rate F2 where N>M and F1<F2. Each data stream is preferably produced by an oversampling data modulator employing a delta-sigma implementation.

Abstract: The tone of video signals is corrected without degrading the tone of certain image features, such as a human face. A gain controller operates and outputs an adjustment value using a histogram output produced by a histogram generator. An average value of picture levels on a screen is detected by an average picture level detector. A histogram correction circuit calculates a look-up table, and a video signal correction circuit corrects the tone of the video signals using the look-up table.

Abstract: A method and apparatus for dynamic contrast improvement in video pictures. There is a strong demand for picture contrast but each video display has a limited dynamic range. The picture contrast can't be increased by simply increasing the video signal amplitude because exceeding the display dynamic range in some video scenes causes unwanted disturbing effects. According to the present invention the video pictures are analysed framewise in real time and the parameters of a transfer function for contrast improvement are adjusted depending on the analysis results for the best subjective picture quality.

Abstract: In the &ggr; correction circuit, a crossover point arithmetic processing unit performs arithmetic processing for each region on crossover points y in the output data direction of a &ggr; correction crossover line based on a plurality of slope data A respectively specified for each of a plurality of regions and crossover point positions X in the input data direction set in advance.

Abstract: An image display apparatus is provided for reducing occurrences of moving image false-edges by preventing profound changes in “on”/“off” subfield distribution, and for displaying a sharp image that does not appear blurred. This is achieved by effectively dividing one TV field and by displaying a gray level of an input image signal using an “on”/“off” subfield combination, out of possible “on”/“off” subfield combinations for displaying the gray level, in which a number of subfields with large luminance weightings that are “on” is minimized.

Abstract: An image display method displays an image by different gradation conversion in every pixel, on the basis of gradation frequency distribution of luminance of pixels near an edge of the image, and counting of gradation frequency of luminance of pixels near the edge is weighted depending on the coordinate values of each pixel so as to eliminate relative contrast drop in the image central part from the image peripheral parts.

Abstract: A method and apparatus are provided to allow threshold values needed for the desired number of gradations to be set through a simple process when converting image data with numerous values into a low number of gradations. The desired number of gradations is achieved without shading being noticeable even for images having shading. The cumulative frequency distribution of the pixels for each brightness is determined from image data having a brightness range with designated gradations. The average brightness and standard deviation of the portion that is primarily background is determined from this cumulative frequency distribution. The first threshold value is determined on the basis of this average brightness and standard deviation, the second through n-1st threshold values corresponding to the meaningful information are determined on the basis of this first threshold value. An n value conversion process is accomplished using these threshold values.

Abstract: An apparatus for improving the visibility of an image to be displayed is provided in an image signal processor such as a TV or VCR. The image visibility improvement apparatus compares levels of an input image signal with predetermined individual high-level or low-level reference values and outputs the compared result signals. The visibility improvement apparatus increases the level of the image signal if the level of the input image signal is higher than the high-level reference value and decreases the level of the image signal if the input signal is lower than the low-level reference value, according to the results of the comparison. The apparatus thereby further distinguishes the level of the signal of a brighter region from that of a darker region. Thus, the image displayed on a screen can be viewed more easily.

Abstract: A television receiver comprising an information extracting circuit for extracting information from a format or content of an input video signal, a video signal processing circuit for processing this video signal by a program or data, a memory for storing the program and data, a CPU for controlling, operating or driving these elements, and a display device for displaying an image. The video signal processing circuit can, under the control of the CPU, decode the signal, correct or set the picture quality such as gradation and sharpness, or adaptively process an on-screen display based on the input video signal. The television receiver is also able to adaptively extend the functions of the television receiver corresponding to various signal formats.

Abstract: A display device driving for a gray scale expression, wherein at least a sub-field having the highest luminance value among plural sub-fields is further divided into a plurality of sub-field parts.

Abstract: A method and apparatus are provided to allow threshold values needed for the desired number of gradations to be set through a simple process when converting image data with numerous values into a low number of gradations. The desired number of gradations is achieved without shading being noticeable even for images having shading. The cumulative frequency distribution of the pixels for each brightness is determined from image data having a brightness range with designated gradations. The average brightness and standard deviation of the portion that is primarily background is determined from this cumulative frequency distribution. The first threshold value is determined on the basis of this average brightness and standard deviation, the second through n- 1st threshold values corresponding to the meaningful information are determined on the basis of this first threshold value. An n value conversion process is accomplished using these threshold values.

Abstract: In an image enhancement method is disclosed using a histogram equalization for an input image expressed in a predetermined number of gray levels. While calculating the probability density function of the gray levels of the input image, for use in a histogram equalization, the number of occurrences of each gray level are constrained not to exceed a predetermined value. Then a histogram equalization is performed on the input image based on the calculated probability density (or distribution) function. As a result, the mean brightness of the input image does not change significantly by the histogram equalization. Additionally, noise is prevented from being greatly amplified.

Abstract: An amplifier (60) provides an amplified video signal in response to a video input signal supplied thereto. A cathode current sensor (Q3), couples an output of the amplifier to the cathode of a kinescope (20) and also provides an output current (Ik) proportional to the kinescope cathode current. A feedback path (82) applies a portion of the sensed cathode current provided by the cathode current sensor to a circuit node (65 or 63) in the amplifier for imparting gamma correction to images produced by the kinescope. In one application the cathode current is apportioned (Q3, Q5) to provide gamma correction for the kinescope and to provide automatic kinescope bias (AKB) control.

Abstract: An LCD controller for use e.g. in a portable computer provides gray scale shading for both monochromatic and color displays using frame rate control modulation for intensity shading for each pixel. The gray scale shading process and circuit do not require any memory for storing phase tiling matrices or frame modulation pattern sequences; both of these instead are generated in real time using a linear matrix logic structure. Use of linear matrix operations also allows generation of various phase shifts of frame modulation pattern sequences to provide a better image on the display. In addition to providing programmable 4, 8, or 16 intensity levels, the present method and apparatus provide that vertically, horizontally or diagonally adjacent pixels on the display never have the same phase in the same frame, and in addition that the pixel display drivers are uniformly loaded.

Abstract: The video signal data of one of the three primary color signals having the maximum level is adjusted with regard to the amplitude level and the DC level thereof in accordance with a predetermined control data. A difference between the adjusted video signal data and a predetermined threshold level is calculated, and the control data is corrected by ones complement of the differential data. The video signal data of the three primary color signals are adjusted respectively, with regard to the amplitude level and DC level thereof in accordance with the corrected control data. In other words, merely with respect to the digital video signal data with the maximum level, the control and brightness controls are conducted. Then, a difference between the resultant video signal data and a predetermined threshold level is obtained for adjusting the respective contrast levels of the three primary color signals by using ones complement of the obtained differential data.

Abstract: A method and apparatus for reducing after images in motion video display. In the present invention, an intensity scaled image of a previous frame or set of frames is subtracted from the present frame before displaying the present frame. In the exemplary embodiment, the scaling factor is determined by measuring the intensity of the after image for the display device. In a preferred embodiment, the after image reduction system of the present invention takes into account the nonlinearities of the display device. That is the nonlinear relationship between the voltage applied to a display device and the intensity of the resulting display.

Abstract: According to a method and a system of the present invention, a gray-level data is generated from a binary image while reducing the vertical brightness transition, and a display with a reduced flicker is enabled in an interlaced scanning system. A filtering operation is conducted with respect to each of the pixels in a dot matrix by using the data of each pixel and the dot matrix data of the pixel adjacent to the pixel in a vertical direction, thereby generating a gray-level data and writing the data into a frame memory. A display with a reduced flicker may be conducted by transforming the gray-level data into a predetermined set of colors consisting of a foreground color, a background color, and an intermediate color thereof.

Abstract: Cost effective video clipping circuitry and method achieve lower distortion color television broadcasting. Excess "white" level voltage peaks in otherwise standard (e.g., that of the National Television Standards Committee) color line video signals are clipped by a unique arrangement to prevent over-modulation of an RF broadcast carrier. The circuitry includes amplifier circuitry for substantially amplifying a line video signal above standard levels, diode clipping circuitry for clipping excess white levels from the signal after it has been amplified thereby reducing distortion otherwise caused by an inherent non-linear initial conduction characteristic of the diode clipping circuitry, and attenuator circuitry for attenuating to standard levels the signal after clipping so as to obtain reduced luminance and chrominance distortion.

Abstract: An image processing apparatus prevents an increase in random noise and the like produced by distributing a transformation error, which is produced at the time of a level-number transformation, to unprocessed pixel data. Error data X.sub.n is added to pixel data, which has entered via an input unit, by an adder. Thereafter, the resulting data is subjected to a level-number transformation by a binarizing circuit. Transformation error produced at the time of the level-number transformation is calculated by an error arithmetic unit. The transformation error thus calculated is distributed to unprocessed pixel data by an error-diffusion unit, and the error is accumulated in a line buffer memory as error data. When processing of a prescribed number of lines has ended, a line-number discriminating circuit clears the error data that has been accumulated in the line buffer memory. As a result, an increase in random noise is prevented.

Abstract: An image enhancement system that efficiently enhances gray scale images, wherein an analog scene is captured and a resulting analog signal is digitized to a raw gray scale image S. Image S is divided into M disjoint non-empty regions R.sub.1 . . . R.sub.M, where S.sub.i identifies region R.sub.i of S. The raw digitized signal S.sub.i is processed in accordance with an enhancement algorithm to obtain a set of enhancement parameters (offsets P.sub.i =(s.sub.ai, s.sub.bi) and weights (w.sub.i)). Digital offsets P.sub.i =(s.sub.ai, s.sub.bi) are converted to analog offsets Q.sub.i =(v.sub.ai, v.sub.bi). The analog signal is stretched and clipped and converted to a digital signal that is an enhanced image signal T.sub.i. The enhanced image signal is multiplied by weight w.sub.i to obtain the final enhanced image U.sub.i. Image U.sub.i forms the region R.sub.i of a final enhanced image U. The multiplied signals are summed to produce an enhanced summed image of the scene.

Abstract: An image memory device is so adapted as to make it possible to use an image pick-up device having any characteristic and a display unit having any characteristic. The image memory device includes an input look-up table and an output look-up table. Data for performing a reverse gamma-correction is set in the input look-up table in advance in dependence upon the image pick-up device used. By virtue of the reverse gamma-correction, the image data is provided with linear characteristics. The reverse gamma-corrected data is stored in the memory. Data for performing a gamma correction is set in the output look-up table in advance in dependence upon the display unit used.

Abstract: In a system for the reproduction of natural images on a display or printer, unviewable negative brightness caused by noise or grain in individual shadow pixels, into adjacent pixels is diffused into adjacent pixels made excessively bright by the same noise or grain process. The visual effect of this diffusion produces truer, deeper blacks in shadow areas, enhances shadow contrast and detail, and reduces perceived noise in shadow areas.

Abstract: A video monitor contrast reference gray scale apparatus, and method of use thereof, wherein the apparatus comprises a reference gray scale housing, a reference gray scale which comprises a plurality of fields which provide a contrast range on the reference gray scale, a light source which is located inside the reference gray scale housing and which provides illumination to the reference gray scale, and a power supply for providing power to the light source. The reference gray scale is located in the reference gray scale housing, and further, the power supply provides power to the light source so as to provide illumination of the reference gray scale. A method for utilizing the apparatus for matching a contrast range of a camera video assist with a contrast range of a film camera negative. A method for matching a contrast range of a reference gray scale with a contrast range of a film camera negative, in conjunction with an adjustable contrast filter device and/or a camera viewfinder ocular.