Matsushita Electric Industrial Co., Ltd.

Daniel Qiang Zhu

Thomas J Leacock

Kevin J Stec

James D Noecker

Kaarlo Juhani Hamalainen

A digital signal processing (DSP) method to process rendered text in order to achieve up to 300% of the horizontal resolution on any suitable digital display devices such as LCD, PDP and DLP. When the text is rendered, a single picture element (a &ldquo;pixel&rdquo;) of a matrix display screen is actually composed of three &ldquo;sub-pixels&rdquo;: one red, one green, and one blue (RGB or BGR). Taken together this sub-pixel triplet makes up what has been traditionally thought of as a single pixel. By staggering and processing the sub-pixel elements horizontally, font resolution is effectively increased to the maximum of 300%. There are three processing steps involved. First, the color image is expanded to a gray scale image having triple the number of horizontal pixels as the original image by interleaving the sub-pixels. Next, a black and white text/graphics (TG) detector is deployed to identify the TG of interest in the gray scale image. Then, the, detected TG and only the detected TG is subject to a morphological thinning operation so that the TG approximates fonts (or graphics) that would be generated from a sub-pixel rendering engine. Finally, the processed TG display data is filtered to minimize color fringing while maximizing its resolution. The resulting display data including the processed TG data and the unprocessed color signals are converted back to the sub-pixels (e.g., RGB or BGR) domain and displayed.

Method and apparatus for improving the definition of black and white text and graphics on a color matrix digital display device

A block matching system matches a motion block in one video image frame to a matching block another video image frame. The system includes a plurality of Hadamard transform processors which transform the motion block and a plurality of trial matching blocks from the other video image frame. The transformed matching blocks are then compared to the transformed motion block, and the transformed matching block which has the smallest difference relative to the transformed motion block is determined. The matching block which corresponds to the determined transformed matching block is selected as the matching block for the motion block. The block matching system may transform motion blocks having different numbers of rows and columns. In one application, the system matches a relatively large motion block in the one frame to a corresponding large matching block in the other frame and determines a displacement between the matching block and the motion block. This displacement is used to guide the selection of trial matching blocks when smaller motion blocks in the one frame are matched to blocks in the other frame.

Motion estimation using orthogonal transform-domain block matching

A system and method for format conversion for use with images containing mixed video and computer generated imagery. A first intermediate scaled image is generated using a first interpolator which has a relatively wide passband and a narrow transition band to the stop band. This interpolator retains high frequency components in the interpolated image but may introduce ringing distortion adjacent to strong edges. The first intermediate scaled image is then processed through an edge extractor which extracts strong edges but ignores any associated ringing distortion. The output signal of the edge detector is a scaled edge image. Next, a second intermediate scaled image is generated using a second interpolator which has a narrower passband and a more gradual transition band. This interpolator produces an image having reduced high frequency components relative to the original image. Then the scaled edge image is added to the second ma intermediate scaled image to produce a converted image having substantially the same high frequency components as the first intermediate scaled image but no ringing distortion components.

System and method for scaling combined video and computer generated imagery

A digital display device, such as a plasma display or a digital DMD based light digital project employs a minimum moving pixel distortion (MPD) set of codewords for reducing visually perceived artifacts viewed on a DDD, specially on a plasma display panel (PDP). The plasma display device includes a minimum MPD mapping process, which maps by, for example, a ROM look-up table, received pixel intensity values into intensity levels corresponding to selected ones of the set of codewords. By increasing the number of subfields (or rounding the least significant bits (LSBs) of the intensity pixels), redundant codewords that express pixel intensities can be generated based on the sustain pulse vector with predetermined constraints. An optimal set of codewords can be determined using a dynamic programming method which minimizes a measure of apparent error in a transition from a gray scale produced by one codeword to a gray scale produced by a next successive codeword. The optimal codewords are stored in a ROM lookup table as display data by a plasma display controller. The plasma display controller then provides the display data, line by line, to the plasma display panel (PDP) using a scan driver and a data driver. Once the display data is loaded into the PDP for an image, the plasma display controller enables the sustain pulse drivers to illuminate the addressed cells with the intended sustain pulse train encoded by the codeword.

Motion pixel distortion reduction for digital display devices using

A digital display device, such as a plasma display or a digital micromirror device (DMD) based digital light projector, employs a minimum moving pixel distortion (MPD) set of codewords for reducing visually perceived artifacts viewed on a digital display device (PDP). The digital display device includes a minimum MPD mapping process, which maps by, for example, a ROM look-up table, corresponding present and previous pixel intensity values from first and second image frames into a preferred equalizing code value corresponding to the present pixel intensity value. An optimal set of equalizing codewords is determined by comparing objective measures of MPD error for each of a plurality of trial equalizing codewords and selecting the codeword having the smallest measure of MPD error. The optimal equalizing codewords are stored in a ROM lookup table which is addressed by the previous and current codewords. Each current codeword and its corresponding codeword from a previous frame are applied to the ROM lookup table which provides the corresponding equalized codeword. This equalizing codeword replaces the current codeword in the display data. The digital display device controller then provides the display data, line by line, to the digital display device (PDP) using a scan driver and a data driver. Once the display data is loaded into the PDP for an image, the digital display device controller enables the sustain pulse drivers to illuminate the addressed cells with the intended sustain pulse train encoded by the codeword.

Motion pixel distortion reduction for a digital display device using

The present invention is embodied in an apparatus and method for converting a progressive video signal to an interlaced video signal from which the progressive video signal may be recovered. The invention is further embodied in an apparatus and method for converting such an interlaced video signal to a progressive video signal. A progressive-to-interlaced video converter includes a progressive video preprocessor and a converter. The progressive video preprocessor replaces at least one scan line in a video frame by its preceding or succeeding scan line. Alternatively, the preprocessor may assign a predetermined value to one or multiple scan lines at appropriate position(s) in a frame. In either scenario, each frame will carry at least one redundant scan line. The frame modification information will be encoded to an ancillary data section of a digital video stream. An interlaced-to-progressive video converter includes an ancillary data preprocessor, a recursive interlaced-to-progressive converter and two digital standards converters. The preprocessor decodes original frame modification information from the ancillary data section of a digital video stream and provides decoding parameters to the interlaced-to-progressive converter. A digital standards converter is used to convert the resulting 24-frame-per-second progressive video signal to a 60-frame-per-second progressive video signal using a 3:2 pull down. A second digital standards converter is also used to produce a 30-frame-per-second interlaced video signal by repeating every 5th field of the 24-frame-per-second interlaced video input.

Method and apparatus for converting a digital interlaced video signal

A plasma display device employs a minimum moving pixel distortion (MPD) set of codewords for reducing visually perceived artifacts viewed on a plasma display panel (PDP). The plasma display device includes a minimum MPD mapping process, which maps by, for example, a ROM look-up table, received pixel intensity values into intensity levels corresponding to selected ones of the set of codewords. By increasing the number of subfields (or rounding the least significant bits (LSBs) of the intensity pixels), redundant codewords that express pixel intensities can be generated based on the sustain pulse vector with predetermined constraints. An optimal set of codewords can be determined though (1) a random search; (2) an exhaustive search; (3) dynamic programming or (4) a genetic algorithm based search which minimizes the MPD distance. The mapped codewords are stored in a ROM lookup table as display data by a plasma display controller. The plasma display controller then provides the display data, line by line, to the plasma display panel (PDP) using a scan driver and a data driver. Once the display data is loaded into the PDP for an image, the plasma display controller enables the sustain pulse drivers to illuminate the addressed cells with the intended sustain pulse train encoded by the codeword.

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Columbus, NJ, United States of America

Daniel Qiang Zhu