497results about How to "Avoid artifacts" patented technology

To produce a paused MPEG coded video stream from an original MPEG coded video stream, an I frame is extracted from the original stream, and a Group of Pictures for a “pause” (a pause GOP) is constructed containing the extracted I frame, some “frozen” frames, and padding. Each “frozen” frame is a P frame that repeats the I frame. When a pause is requested in the original stream, a seamless transition is made from the I frame to the pause GOP, and the pause GOP is played in a loop until a resume is requested. To resume, the pause GOP is completed and a seamless transition is made to continue in the original stream from the I frame where the pause had begun.

A graphics system including a custom graphics and audio processor produces exciting 2D and 3D graphics and surround sound. The system includes a graphics and audio processor including a 3D graphics pipeline and an audio digital signal processor. The graphics pipeline performs Z-buffering and optionally provides memory efficient full scene anti-aliasing (FSAA). When the anti-aliasing rendering mode is selected, Z value bit compression is performed to more efficiently make use of the available Z buffer memory. A Z-clamping arrangement is used to improve the precision of visually important Z components by clamping Z values to zero of pixels that fall within a predetermined Z-axis range near the Z=0 eye / camera (viewport) plane. This allows a Z-clipping plane to be used very close to the eye / camera plane--to avoid undesirable visual artifacts produced when objects rendered near to the eye / camera plane are clipped--while preserving Z value precision for the remaining depth of the scene. In an example implementation, a Z value compression circuit provided in the graphics pipeline is enhanced to effectuate Z-clamping within the predetermined range of Z values. The enhanced circuitry includes an adder for left-shifting an input Z value one or more bits prior to compression and gates for masking out the most significant non-zero shifted bits to zero.

An electrophoretic medium has walls defining a microcavity containing an internal phase. This internal phase comprises electrophoretic particles suspended in a suspending fluid and capable of moving therethrough upon application of an electric field to the electrophoretic medium. The average height of the microcavity differs by not more than about 5 μm from the saturated particle thickness of the electrophoretic particle divided by the volume fraction of the electrophoretic particles in the internal phase.

A power-scalable hybrid technique to reduce blocking and ringing artifacts in low bit-rate block-based video coding is employed in connection with a modified decoder structure. Fast inverse motion compensation is applied directly in the compressed domain, so that the transform (e.g., DCT) coefficients of the current frame can be reconstructed from those of the previous frame. The spatial characteristics of each block is calculated from the DCT coefficients, and each block is classified as either low-activity or high-activity. For each low-activity block, its DC coefficient value and the DC coefficient values of the surrounding eight neighbor blocks are exploited to predict low frequency AC coefficients which reflect the original coefficients before quantization in the encoding stage. The predicted AC coefficients are inserted into the low activity blocks where blocking artifacts are most noticeable. Subject to available resources, this may be followed by spatial domain post-processing, in which two kinds of low-pass filters are adaptively applied, on a block-by-block basis, according to the classification of the particular block. Strong low-pass filtering is applied in low-activity blocks where the blocking artifacts are most noticeable, whereas weak low-pass filtering is applied in high-activity blocks where ringing noise as well as blocking artifacts may exist. In low activity blocks, the blocking artifacts are reduced by one dimensional horizontal and vertical low-pass filters which are selectively applied in either the horizontal and / or vertical direction depending on the locations and absolute values of the predicted AC coefficients. In high activity blocks, de-blocking and de-ringing is conducted by 2- or 3-tap filters, applied horizontally and / or vertically, which makes the architecture simple.

A color mapping method maps an input image signal (IS) into an output image signal (OS) for a display (DD) with display pixels (Pi) having sub-pixels (RP, GP, BP, YP) with primary colors (RW, GW, BW, YW) defining a display color gamut (WG). A look-up table (1) comprises stored luminances (LU) of reflective spectra (RS) at different chromaticities (λO) within the display color gamut (WG). The reflective spectra (RS) are spectra of reflective objects (RO) having a substantial maximum reflectivity at the corresponding chromaticities (λO). The color mapping method comprises a gamut mapping (2), retrieving (3) a looked-up luminance (Y1), a factor determination (4), and adapting the mapped luminance (Ym; Y). The gamut mapping (2) maps the input image signal (IS) having input pixel colors defined by an input luminance (Y) and an input chromaticity (x, y) into a mapped image signal (MS) having corresponding mapped pixel colors defined by a mapped luminance (Ym; Y) and a mapped chromaticity (xm, ym). The input pixel colors lie within an input color gamut different than the display color gamut (WG). The looked-up luminance (Y1) is retrieved (3) by looking up the stored luminance (LU) in the look-up table (1) at the mapped chromaticity (xm, ym). The factor (F) is determined (4) from a difference between the looked-up luminance (Y1) and the mapped luminance (Ym; Y). The mapped luminance (Ym; Y) is adapted (5) by using the factor (F; G) to obtain an output luminance (Ys) nearer to the looked-up luminance (Y1) than the mapped luminance (Ym). The image output signal (OS) is defined by the mapped chromaticity (xm, ym) and the output luminance (Ys).

A method of imaging an object that includes directing a plurality of x-ray beams in a fan-shaped form towards an object, detecting x-rays that pass through the object due to the directing a plurality of x-ray beams and generating a plurality of imaging data regarding the object from the detected x-rays. The method further includes forming either a three-dimensional cone-beam computed tomography, digital tomosynthesis or Megavoltage image from the plurality of imaging data and displaying the image.