Abstract: A method and an apparatus are provided for correcting the frequency characteristics of a carrier chrominance signal, which, by use of the correcting signal for the frequency characteristic involved in a vertical blanking interval, determine whether the frequency characteristics of the carrier chrominance signal are distorted and correct the frequency characteristics. A band pass filter is used which determines a degree of the frequency characteristic distortion of the carrier chrominance signal band from the correcting signal for the frequency characteristic, and has a gain in accordance with the determined result. If the frequency characteristic of the carrier chrominance signal involved in the input composite video signal is distorted by the frequency characteristics and so on of the analog broadcasting radio channel and the broadcasting receiver, the distortion is corrected whereby a stable reproduction of the color signal is possible irrespective of the broadcasting channels and the broadcasting receiver.

Abstract: In a video system, a method and system for cross-chrominance removal using motion detection are provided. A luma motion detector in a motion adaptive deinterlacer may be used to determine a chroma current motion for a pixel in a video frame. The chroma current motion may be modified, based on a chroma motion mechanism comprising of an edge detection, a back-off, and a motion biasing, when the output pixel is found to be in a static chroma area of the video frame. A static chroma threshold parameter may be used to determine whether the output pixel is in a static chroma area. A cross-chroma reduction determined based on the current chroma motion, may be blended in the motion adaptive deinterlacer with a spatial average approximation of the output pixel to remove the cross-chrominance from the output chroma.

Abstract: Provided is a method of removing noise from digital moving picture data reducing the number of frames used in a temporal filtering operation and able to detect motion between frames easily. The method comprises a method of spatial filtering, a method of temporal filtering, and a method of performing the spatial filtering and the temporal filtering sequentially. The spatial filtering method applies a spatial filtering in a YCbCr color space, preserving a contour/edge in the image in the spatial domain, and generating a weight that is adaptive to the noise for discriminating the contour/edge in the temporal filtering operation.

Abstract: In a system for synchronizing video signals using a sampled signal having a sampling cycle, the system includes a coarse offset module configured to receive a first input signal and a second input signal and to alter an offset of the first and second input signals to produce a first intermediate signal and a second intermediate signal offset relative to each other by an integer multiple of the sampling cycle and the system further includes a fine offset module coupled to the coarse offset module to receive the first and second intermediate signals and configured to alter an offset between the first and second intermediate signals relative to each other by an amount less than the sampling cycle to produce a first output signal and a second output signal.

Abstract: A temporally recursive chrominance signal noise reduction can be achieved by subtracting a delayed version of the chrominance output signal from the chrominance input signal and by multiplying the related difference signal by a variable share factor and adding the resulting signal to the chrominance output signal, for achieving different degrees of noise reduction. From the difference signal a motion representative value and a value representing the presence of a smear effect are calculated and used to calculate the variable factor. After having been multiplied by this factor, the difference signal is combined with a frame-delayed version of the chrominance output signal in order to form the noise-reduced chrominance output signal.

Abstract: A dynamic motion degree of a video composite signal is estimated. A chrominance signal after Y/C separation and chrominance demodulation is narrow-band low pass filtered (NBLPF) and wide-band low pass filtered (WBLPF), so as to generate a narrow-band filtered signal and a wide-band filtered signal. The narrow-band filtered signal and the wide-band filtered signal are weighted based on the estimated dynamic motion degree, so as to determine how much high frequency component of the chrominance signal is reserved. In the static image processing, more high frequency component is reserved, so as to reduce the color transition issue and keep the image color being sharp. In the dynamic image processing, more high frequency component is filtered, so as to reduce the cross color issue.

Abstract: A method for suppressing cross-coloration in a video display device includes receiving high-frequency components of luminance signals corresponding to scanlines of an image frame, determining luminance transitions according to the high-frequency components of the luminance signals, and adjusting chrominance signals of the scanlines according to the luminance transitions.

Abstract: A method and apparatus for cross color and/or cross luminance suppression. The apparatus checks for three conditions in determining the stillness of an image. Similarity between two frames, which are one frame apart, is examined. Similarity between two adjacent frames is also examined. Similarity among three successive frames is also examined. By integrating the results of such three conditions, the stillness of the image is determined. Only when the image is deemed still/stationary, is the cross color and/or cross luminance suppressing operation being performed.

Abstract: A noise reduction circuit and method effectively reduce noise with a simple structure regardless of the partial content of an image while suppressing an increase in the capacity of the image memory used and process delays. The present invention forms noise-reduced data by utilizing a correlation between from the difference between a pixel subjected to noise reduction and data of a pixel that is shifted by a predetermined amount in a time direction and/or spatial direction, and forms a difference cause discriminating signal indicating whether the difference is due to a valid change of the image. The noise-reduced data and the difference cause discriminating signal are formed for a plurality of different correlations. Final noise-reduced video data are obtained by selecting a method for determining the final noise-reduced video data based on the difference cause discriminating signals, and accordingly selecting/combining the plurality of noise-reduced data.

Abstract: A color correction method, a color correction device, and a color correction program that can achieve color correction processing with a color table with a fine spacing, while preventing the increase in memory capacity. A signal (YCC signal) of a luminance—color difference system is subjected to matrix conversion with a matrix conversion unit 10 and converted into a signal (RGB signal) of a display signal system. The adjustment amount relating to the signal of the display signal system is stored in a RGB color adjustment LUT 20. An interpolation processing unit 20 conducts interpolation processing by referring to the RGB color adjustment LUT 20 and outputs the color-corrected RGB signal after correction.

Abstract: A superior Color Transient Improvement technique is adaptive to the local image features, so that more natural color edge transition improvement can be accomplished. A gain control function is provided that depends on the local image feature so that different regions of the image can be treated differently. Further, a correction signal is controlled in such a way (by the local image feature) that neither undershoot nor overshoot occurs, eliminating the need for post-processing for undershoot/overshoot removal.

Abstract: According to embodiments of the present invention, a method for processing an image in a video data is disclosed. The video data comprises at least a first frame and a second frame. The first frame is composed of a first even field and a first odd field, while the second frame is composed of a second even field and a second odd field. The method comprises obtaining a first difference set between pixel information of the first frame and pixel information of the second frame, wherein the first frame and the second frame are adjacent to each other; examining a first criterion with the first difference set; and performing cross color suppressing operation on pixel information of the second frame according to a set of stationary image judgment information comprising the result of the first criterion examination.

Abstract: A video decoder removes noise caused by a luminance signal component when separating a chrominance signal from a composite video baseband signal.

Abstract: Plasma Display Panels (PDP) are becoming more and more interesting for TV technology. Due to the larger size of PDPs, with larger viewing angle the large area flicker effect will become more serious in the future, in particular when handling 50 Hz video standards. This invention proposes a different sub-field organisation, with different coding, which reduces large area flicker artefact, and which is characterised by: 1. Grouping of sub-fields (SF) in 2 sub-field groups (G1, G2), of similar structure. 2. Adjusting the starting times of the two sub-field groups to a time raster corresponding to a doubling of the frame repetition rate by adding a first blanking period of a first dedicated length behind the last sub-field of the first sub-field group and a second blanking period of a second dedicated length behind the last sub-field of the second sub-field group.

Abstract: An error diffusion system in accordance with an embodiment of the present invention adjusts the color depth of an RGB signal using error diffusion without the using an expensive frame buffer. Specifically, a color depth adjustment unit in accordance with the present invention can perform error diffusion on an RGB signal using two error buffers, which are smaller in memory size than typical line buffers that would be used for the video stream.

Abstract: A dot detection section of a dot-interference detection section detects a portion where pixels are arranged as “dark-bright-dark” or “bright-dark-bright” in the horizontal direction, within a Y signal containing dot interference, separated by a YC separation process, and outputs the detection result as dot values to a horizontal array checking section and a vertical array checking section. The horizontal array checking section detects whether or not dot values of a predetermined number of pixels arranged horizontally in such a manner as to contain a subject pixel, have the same value. The vertical array checking section detects whether or not dot values of a predetermined number of pixels arranged vertically in such a manner as to contain a subject pixel, are alternately generated as 1 and 2. An enhancement processing section performs an enhancement process on the Y signal of portions other than the portions where dot interference occurs.

Abstract: An oblique correlation detection section detects correlation in an oblique direction (oblique correlation) of a composite video signal. A line correlation chrominance separation section extracts a first chrominance signal from the composite video signal based on vertical correlation of the composite video signal. A first chrominance signal acquisition section acquires a second chrominance signal based on horizontal self-correlation of the first chrominance signal. The first chrominance signal acquisition section detects the self-correlation within a range corresponding to the degree of the oblique correlation detected by the oblique detection section.

Abstract: A filter device (1) includes a main filter unit (10), such as a 2-D comb filter, implemented in hardware, with an input for receiving a video signal (?) and an output for providing a filtered video signal (?1), a controllable temporal noise reduction unit (20) receiving the filtered video signal (?1) from the main filter unit (10), to perform a noise reduction operation on the filtered video signal (?1), and a unit (14, 30, 40) for detecting a very low amount of motion in a video image of the filtered video signal (?1) and for controlling the controllable temporal noise reduction unit (20) on the basis of the detected very low amount of motion, so as to enable the filter device (1) to reduce cross-luminance and/or cross-color as well when only a very low amount of motion is present in the signal.

Abstract: Noise reduction is an important feature in consumer television. This is realized by spatial, temporal or spatio-temporal filters. Spatial filters require pixels from within one image, while temporal filters require samples from two or more successive images. The spatio-temporal filter unit (100) integrates spatial and implicit motion-compensated temporal noise reduction in one filter. For the motion compensation, no motion vectors are required. The spatio-temporal filter unit (100) is provided with a sigma filter (112) having one filter kernel (107) designed to operate on the pixels from both a current image and from the output of the spatio-temporal filter unit, being a temporally recursive filtered image. The operation of the spatio-temporal filter unit (100) can be adjusted by varying the thresholds of the sigma filter (112) and the selection of pixels. The adjustments can be controlled by a motion estimator (222), a motion detector (224) and a noise estimator (220).

Abstract: A digital camera includes an LCH conversion circuit. The LCH conversion circuit detects an L component value, a C component value and an H component value from each of pixel signals forming an image signal of an object being photographed. A plurality of reference L component values, reference C component values and reference H component values are held on a reference value table. A plurality of target L component values, target C component values and target H component values are held on a target value table. An L control circuit, a C control circuit and an H control circuit correct the L component value, the C component value and the H component value of each pixel based upon the reference value table and the target value table. A plurality of target values held on the target value table is arbitrarily controlled by a key operation or the like by an operator.

Abstract: A video signal processing method and apparatus eliminates dot crawls and cross color interferences from a component video signal that has been subjected to Y/C separation. Components at a horizontal frequency of 3.58 MHz and a temporal frequency of 15 Hz are extracted from luminance signal data using a horizontal filter and a time filter. When the absolute value of the component value is equal to or larger than a predetermined value, an output of the horizontal filter is subtracted from the luminance signal data by a subtracter, thereby eliminating dot crawls.

Abstract: The invention relates to a method and apparatus for detecting asymmetry in transient signals and to a method and apparatus for correcting such asymmetry.

Abstract: A process of filtering digital images to reduce image flicker. An anti-flicker filtering is performed after a step of calculating the image and before a step of displaying the image so that the flicker is filtered as soon as the image is created.

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 method of reducing color aliasing artifacts from a color digital image having color pixels includes providing luminance and chrominance signals from the color digital image; using such luminance and chrominance signals to separate the image into textured and nontextured regions having boundaries; downsampling the chrominance signals and texture region mapping; producing cleaned chrominance signals in the textured regions in response to the boundaries of the textured region and chrominance signals; producing cleaned chrominance signals in the nontextured regions in response to the chrominance signals; upsampling the noise-cleaned chrominance signals; and using the luminance and upsampled noise-cleaned chrominance signals to provide a color digital image having reduced color aliasing artifacts.

Abstract: A method and apparatus for equalizing a signal containing high definition television information in the presence of co-channel NTSC interference employs an equalizer having feed forward and decision feedback filters. A comb filter is inserted ahead of the equalizer when NTSC co-channel interference is present. A selected tap of the decision feedback filter is set to a zero value when the signal is being equalized during an intitial blind operating mode. The decision feedback filter taps are updated afterwards, in a decision-directed operating mode.

Abstract: A method and apparatus for reducing noise in an image sequence is provided. Images in the image sequence are recursively filtered on an area-by-area or, for example, pixel-by-pixel, basis. A pixel from an image is compared to a similarly located pixel from a previous image. A difference between one or more parameters of the pixels is determined. One or, preferably, two thresholds are used to classify three types of differences. Depending on the classification, the two pixels are blended together according to their parameters in varying amounts. Relatively small differences indicate a large fraction of the previous pixel to be combined with a small fraction of the current pixel. This substantially reduces the effects of random noise, which tends to cause relatively small, transient variations in the pixels of each image of the image sequence. Relatively large differences indicate the use of 100% of the current pixel without combining any of the previous pixel.

Abstract: The present invention provides an image compensation apparatus, by which a hardware structure is simplified and by which resolution of a remanded color gamut is enhanced when an inputted digital image is compensated to fit the characteristics of a display device. The present invention includes a 3-dimensional look-up table storing 3-dimensional transformation data corresponding to upper n-bits of an input image and a color interpolation unit outputting a final color-transformed image by performing linear interpolation using the 3-dimensional transformation data outputted from the 3-dimensional look-up table and 3-dimensional data corresponding to lower m-bits of the input image.

Abstract: A method, apparatus, and system for reducing cross-color distortion in an image produced by a composite video signal decoder is disclosed. Cross-color distortion, which is due to high frequency luminance being passed through the chrominance signal, is reduced by processing chrominance phases (i.e., color information) associated with a reference pixel and pixels adjacent the reference pixel to derive a scaling factor for scaling the reference pixel. The reference pixel is attenuated by the scaling factor if none of the adjacent pixels have a chrominance phase that is similar to the reference pixel.

Abstract: An error diffusion system in accordance with an embodiment of the present invention adjusts the color depth of an RGB signal using error diffusion without the using an expensive frame buffer. Specifically, a color depth adjustment unit in accordance with the present invention can perform error diffusion on an RGB signal using two error buffers, which are smaller in memory size than typical line buffers that would be used for the video stream.

Abstract: A method for extending bit-depth of display systems. The method includes creating pseudo-random noise from human visual system noise. When applied to the image data, the noise causes spatiotemporal dithering. The pseudo-random noise is combined with image data, producing noise-compensated image data. The noise-compensated image data is them quantized.

Abstract: A method, apparatus, and system for reducing chrominance artifacts in a luminance signal obtained from a composite NTSC television signal is disclosed. Chrominance artifacts are reduced by detecting chrominance artifacts in the luminance signal of a current line and a previous line, weighting the luminance signal of the current line and the luminance signal of the previous line based on the detected chrominance artifacts, and combining the weighted luminance signal of the current line and the weighted luminance signal of the previous line for use as the luminance signal for the current line. Reducing chrominance artifacts reduces the occurrence of “hanging-dots” displayed on a television monitor, which are due to incompletely canceled chrominance artifacts in the luminance signal.

Abstract: A video apparatus includes a circuit for reducing noise in applied input video signals. The noise reducing circuit is provided with a temporal noise filter (S1, LUT, M), a down-sample unit (D) for obtaining a spatial down-sampling of video signals (Vi) of subsequent pixels, these down-sampled video signals being supplied to the temporal noise filter (S1, LUT, M), and an up-sample unit (U) for generating, in response to noise output signals obtained in the temporal noise filter (S1, LUT, M), noise signals of the pixels, and a subtractor (S2) for subtracting the noise signals from the respective input video signals (Vi).

Abstract: Plasma Display Panels (PDP) are becoming more and more interesting for TV technology. Due to the larger size of PDPs, with larger viewing angle the large area flicker effect will become more serious in the future, in particular when handling 50 Hz video standards. This invention proposes a different sub-field organisation, with different coding, which reduces large area flicker artefact, and which includes grouping of sub-fields in two sub-field groups wherein the two sub-field groups are identical in terms of the most significant sub-fields and different in terms of the least significant sub-fields, and a sub-field coding process that distributes luminance weight symmetrically over the two sub-field groups so as to minimize the large area flicker luminance component.

Abstract: A method of reducing color aliasing artifacts from a color digital image having color pixels includes providing luminance and chrominance signals from the color digital image; using such luminance and chrominance signals to separate the image into textured and nontextured regions having boundaries; downsampling the chrominance signals and texture region mapping; producing cleaned chrominance signals in the textured regions in response to the boundaries of the textured region and chrominance signals; producing cleaned chrominance signals in the nontextured regions in response to the chrominance signals; upsampling the noise-cleaned chrominance signals; and using the luminance and upsampled noise-cleaned chrominance signals to provide a color digital image having reduced color aliasing artifacts.

Abstract: An image processing apparatus operates to process input signal samples representative of at least part of a color video image to produce legal color signal samples representative of a legal color version of the image. The apparatus comprises an adjustment factor generator, which operates to generate a plurality of adjustment factors which when combined with the input signal samples have an effect of converting illegal color pixels of the color image into legal color pixels, an adjustment factor biasing processor coupled to the adjustment factor generator, which operates to change the adjustment factors by combining each of the adjustment factors with a biasing constant, and a color legalizer coupled to the biasing processor, which operates to combine the biased adjustment factors with the input signal samples to produce the legalized color signal samples.

Abstract: The invention provides an improved method and system for presenting television signals, including anti-aliasing of text with respect to a background. The background color is determined relatively locally for each element to be anti-aliased, and text or other graphics overlaid on that background are anti-aliased with respect to each relatively local background color. Also, anti-aliasing can be applied to blur text and graphics more vertically than horizontally to reduce flicker, and to blur chrominance more than luminance to reduce cross-chrominance artifacts resulting from Y/C separation. Similar techniques may be used for filtering images in addition to anti-aliasing text characters.

Abstract: An image chrominance signal filtering method and apparatus in which object chrominance information and background chrominance information are extracted in an image format conversion process, based on shape information of luminance signals, and then decimation-filtered or interpolation-filtered. In accordance with the method and apparatus of the present invention, it is possible to avoid a color bleeding phenomenon occurring at the boundaries of objects in an image. Accordingly, there is an advantage in that a degradation in picture quality is prevented.

Abstract: A method and system for correcting luma data and chroma data from a composite signal for a plurality of lines are disclosed. The method and system include correlating line data of the composite signal from a portion of the plurality of lines to provide a plurality of correlation signals. The method and system also include generating a chroma suppression signal based on the plurality of correlation signals. The chroma suppression signal indicates whether to suppress a portion of the chroma data. The chroma suppression signal indicates that the portion of the chroma data should be suppressed when a large luma transition and the chroma data being beneath a threshold are detected.

Abstract: A dot detection section of a dot-interference detection section detects a portion where pixels are arranged as “dark-bright-dark” or “bright-dark-bright” in the horizontal direction, within a Y signal containing dot interference, separated by a YC separation process, and outputs the detection result as dot values to a horizontal array checking section and a vertical array checking section. The horizontal array checking section detects whether or not dot values of a predetermined number of pixels arranged horizontally in such a manner as to contain a subject pixel, have the same value. The vertical array checking section detects whether or not dot values of a predetermined number of pixels arranged vertically in such a manner as to contain a subject pixel, are alternately generated as 1 and 2. An enhancement processing section performs an enhancement process on the Y signal of portions other than the portions where dot interference occurs.

Abstract: The present invention discloses a device and method for eliminating an interfering wave and determining the best orientation for an antenna. A SAW (surface acoustic wave) filter employed in the invention eliminates an interfering wave (a ground analog broadcasting wave) and extracts a video-signal element of a specified channel (a bandwidth of 6 MHz) from an input intermediate-frequency signal so as to output to an A/D converter. The arrangement of the filter, which is a band pass filter having a comb-shaped attenuation characteristic, is such that the first peak of attenuation is made to coincide with the peak of an interfering signal; the A/D converter produces an AGC feedback signal to output to a high-frequency amplifier, an intermediate-frequency amplifier, and an operation unit, respectively; a waveform equalization unit eliminates a ghost image generated due to multi-path interference from the input signal by using an equalizing method such as a learning equalization, a blind equalization, etc.

Abstract: An adaptive filter is disclosed comprising a source (1) for a television signal (f), a delay device (2) for forming delay signals (v0 to v5) from the television signal, a filter combination (3) comprising at least one comb-up device and one comb-down device (3.4, 3.1) for forming filter signals (s1 to s4) from the delay signals, a mixer (5), a decision device (4) for analyzing the delay signals (v0 to v5), and a computing matrix (7) for forming weighting factors (g) for the mixer (5). A manually controllable or data-controllable setting device (8) is coupled to the decision device (4) for changing the mixing behavior in the mixer (5), which is dependent on a predetermined algorithm in the decision device (4) and/or the computing matrix (7).

Abstract: A video frame is decomposed into blocks of pixels. Blocks that contain moving edges are not processed further. The remaining blocks are examined for the likelihood of having color bleeding artifacts, and not processed further if the likelihood is low. The likelihood is determined by examining statistics of the chrominance values. The remaining blocks are de-color bleeding filtered at the chrominance plane, without affecting the corresponding luminance plane.

Abstract: The present invention relates to filtering an interlaced input digital signal containing fields of chrominance information preparatory to converting the format of the signal by means of a downsampling conversion from a 4:2:2 format to a 4:2:0 format. In the invention, the input signal is applied to a delay circuit to derive samples of the input signal representing spatially separated elements from each chrominance field where the spatial separation is of one line. The magnitudes of the samples are compared relative to one another to identify frequencies which fall within different high and low frequency ranges. An adaptive filter has a plurality of frequency responses corresponding to the frequency ranges and a frequency response is selected in accordance with the identified frequency range of the input signal samples.

Abstract: Briefly, in accordance with one embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is adjusted so as to reduce the amount of filtering across temporal discontinuities in the video image sequence. Briefly, in accordance with another embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is dynamically adjusted.

Abstract: A device and method for preventing flicker that occurs while displaying image data by attenuating a high-frequency portion of orthogonal transformed color signals of the image data. The present invention is also directed to a computer-readable recording medium on which a program for flicker prevention is recorded.

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: Systems and methods for correlating color correction instruction between two color correcting devices are disclosed. The method includes performing a nulling test on a representation a first device has of a known standard and retaining the results of the test. A second color correcting device performs a nulling test on the same known standard and the results of this test are retained. From the results of these two tests a color correction instruction of one of the devices may be converted to a color correction instruction on the other device so that substantially the same color correction effect is achieved.

Abstract: A digital camera includes an LCH conversion circuit. The LCH conversion circuit detects an L component value, a C component value and an H component value from each of pixel signals forming an image signal of an object being photographed. A plurality of reference L component values, reference C component values and reference H component values are held on a reference value table. A plurality of target L component values, target C component values and target H component values are held on a target value table. An L control circuit, a C control circuit and an H control circuit correct the L component value, the C component value and the H component value of each pixel based upon the reference value table and the target value table. A plurality of target values held on the target value table is arbitrarily controlled by a key operation or the like by an operator.

Abstract: A tone display method for displaying a tone of an image in a display system which divides a time width of a field of an image signal into a plurality of weighted subfields and controls operation of the subfields.