119 results about "Block transform" patented technology

A method of reducing artifacts in an image previously processed by block transform encoding may comprise the steps of:

• • determining block boundaries;
  • determining an approximate metric of artifact visibility;
  • optionally interpolating across block boundaries;
  • adaptively filtering luminance;
  • optionally adaptively filtering chrominance;
  • adaptively adjusting local saturation variation; and
  • adaptively simulating high spatial frequency image detail;

wherein the adaptive steps are executed to an extent or in an amount depending on the metric or standard or measurement of artifact visibility.

A variable block transform system, medium, and a system, medium, and method for video encoding/decoding using the variable block transform. The system includes a transform block size determination unit that determines the transform block size for components of an input video based on a format, defining the components, of the input video or characteristics of the components, and a transform coding unit that performs transform coding on each of the color components of the input video according to the determined transform block sizes and outputs transform coefficients.

A block transform-based digital media codec more efficiently encodes transform coefficients by jointly-coding non-zero coefficients along with succeeding runs of zero-value coefficients. When a non-zero coefficient is the last in its block, a last indicator is substituted for the run value in the symbol for that coefficient. Initial non-zero coefficients are indicated in a special symbol which jointly-codes the non-zero coefficient along with initial and subsequent runs of zeroes. The codec allows for multiple coding contexts by recognizing breaks in runs of non-zero coefficients and coding non-zero coefficients on either side of such a break separately. The codec also reduces code table size by indicating in each symbol whether a non-zero coefficient has absolute value greater than 1 and whether runs of zeros have positive value, and separately encodes the level of the coefficients and the length of the runs outside of the symbols.

Block-based image processing methods and apparatus that provide a reduction in block-transform image coding artifacts are described. In various embodiments, the invention is directly incorporated into a decoding process. In such embodiments, transform coefficients are modified in simple but particularly effective ways that reduce or eliminate many of the artifacts that were caused by the quantization of the transform coefficients during encoding and/or by independent block processing during encoding. In other embodiments, the invention is used on an image that has already been decoded. In such embodiments image data values are directly modified in a block-based fashion or a forward block transform is applied and then the methods of the invention for processing transform coefficient blocks are used, followed by an inverse transform operation to generate pixel values from the resulting processed transform coefficient blocks.

An encoder, decoder, and corresponding method are disclosed for encoding pixel data as a plurality of block transform coefficients and decoding encoded block transform coefficients to provide reconstructed pixel data, the encoder and/or decoder includes a conditional deblocking filter for filtering only block transitions meeting pre-selected pixel brightness level criteria, where the conditional deblocking filter method includes receiving at least one first pixel adjacent to a block transition, providing a signal indicative of the brightness of the at least one first pixel, comparing the brightness signal with at least one of an upper brightness threshold and a lower brightness threshold, and conditionally filtering a plurality of adjacent pixels including the first pixel at the block transition in response to the brightness comparison.

An apparatus for encoding an audio signal includes the windower for windowing a first block of the audio signal using an analysis window having an aliasing portion and a further portion. The apparatus furthermore includes a processor for processing the first sub-block of the audio signal associated with the aliasing portion by transforming the sub-block from a domain into a different domain subsequent to windowing the first sub-block to obtain the processed first sub-block, and for processing a second sub-block of the audio signal associated with the further portion by transforming the second sub-block from the domain into the different domain before windowing the second sub-block to obtain a processed second sub-block. The apparatus furthermore includes a transformer for converting the processed first sub-block and the processed second sub-block from the different domain into a further different domain using the same block transform rule to obtain a converted first block which may then be compressed using any of the well-known data compression algorithms. Thus, a critically sampled switch between two coding modes can be obtained, since aliasing portions occurring in two different domains are matched to each other.

Image data encoded in accordance with a block transform coding scheme may be processed by estimating from the encoded image data a discontinuity threshold for detecting artificial edges introduced by the block transform coding scheme. Once the encoded image data is decoded, differences between pairs of pixels disposed along a block boundary of the decoded image may be determined. If the difference between a given pair of pixels is less than the discontinuity threshold, the given pair of pixels may be adjusted to reduce the difference below a visibility threshold, thereby improving the quality of the decoded image by reducing or eliminating blocking artifacts.

Image data processing techniques utilizing multiple processes operating on one or more processors of one or more computer systems can be used to efficiently rearrange or reparameterizing image data to form hologram element (hogel) images which can then be used to produce holographic stereograms. These techniques utilize matrix manipulation of portions of image data both within a single process, and across multiple processes typically executing on different processors, and each utilizing a subset of the overall set of image data.

A method of intra-coding blocks of pixels in a digital video sequence is provided that includes selecting a block transform of a plurality of block transforms according to a spatial prediction mode used in generating a block of pixel residual values from a block of pixels, wherein the block transform is based on a single directional transform matrix predetermined for the spatial prediction mode and is a same size as the block of pixel values, applying the block transform to the block of pixel residual values to generate transform coefficients of the residual pixel values, and entropy coding the generated transform coefficients.

A method of watermarking a video signal includes encoding the video signal using at least one encoding parameter that is time-varied according to a watermarking pattern. The parameter affects information lost while encoding the signal. The parameter may be a quantization factor corresponding to a particular coefficient of an encoding transform. The parameter may be an element of a quantization matrix corresponding to a particular coefficient in a block DCT transform. The method may be implemented in devices with limited processing resources by means of a software update. The method enables the devices to imprint an encoded signal with a robust watermark, which may survive subsequent decompression and recompression. Alternatively, a video signal may be watermarked by modifying a magnitude of a non-dc spatial frequency component in a manner which varies with time according to a watermarking pattern. Corresponding watermark detection methods and watermarking devices also are disclosed.

Image frames of a video stream are encoded with the aim of reducing flicker in the video stream when displayed. In one embodiment, the quantization parameter used to quantize an image frame is capped to be not greater than a quantization parameter used to quantize an immediately previous image frame. In another embodiment, the quantization step size used to quantize a macro-block of an image frame is computed based on the value of a quantization error of a co-located macro-block in an immediately previous image frame. In yet another embodiment, macro-block transform coefficients corresponding to high-frequency components are quantized using relatively higher quantization parameter values if the image frame is deemed to contain high activity. In yet another embodiment, flicker-prone macro-blocks of a source frame are replaced by corresponding best-match macro-blocks of a previous reconstructed frame, prior to being encoded.

A hybrid scalable encoder, method, and media are disclosed for processing video signal data as a plurality of block transform coefficients for each of a base layer and an enhancement layer included on a dual standard-definition and high-definition disc. The encoder includes a two-layer decomposition unit for decomposing an original high-definition signal data sequence into base layer data and enhancement layer data, a standard-definition encoder coupled to the decomposition unit for encoding the base layer data as a base layer bitstream embodying a standard-definition data sequence, and a high-definition encoder coupled to the decomposition unit and the standard-definition encoder for encoding the difference between the high-definition data and the standard-definition data as an enhancement layer bitstream embodying a high-definition data sequence.

Discrete Cosine Transforms in a radix-2 block transform method enables true split and merge transform processing of equal sized data halves in the transform domain for enabling recursive merges and splits in transform domain without data degradation. Input data in the time domain or spatial domain during either the split and merge radix-2 forward transform processing is firstly transform processed followed by combinational processing. In the split transform process, whole transformed data is split using combinational processing into first and second transformed data halves in the transform domain as a true split. In the merge transform process, first and second transform halves are merged using combinational processing into a merged transformed data whole in the transform domain. In either case, time or spatial domain input data can be transformed into the transform domain in the form of split halves or merged whole. The split halves can be merged by the merge process combinational processing and the merged whole can be split by the split process combinational processing. The split and merge process combinational processing enable recursive splits and merges in the transform domain.

A system and method of generating a watermarked signal are disclosed. The system segments the signal into overlapping blocks using a window function and processes the overlapping blocks according to whether each block is odd- or even-numbered. The system windows the odd-numbered blocks, modulates the phase of each block in the frequency domain, transforms each modulated block in the time domain, windows each block transformed into the time domain and overlap-adds each odd-numbered block with each even-numbered block to generate the watermarked signal.

A method and system for coding an image using context-based adaptive VLC where transform coefficients are partitioned into blocks having a block dimension of 4nx4m (with n, m being positive integer equal to or greater than 1). Each block is scanned in a zigzag manner to produce an ordered vector of coefficients having a length of 16nxm. The ordered vector is sub-sampled in an interleaved manner to produce nxm sub-sampled sequences of transform coefficients prior to encoding the transform coefficients using an entropy encoder.

An apparatus using a compact blocked and Wavelet transform pair suppresses block artifacts in image compression systems by re-purposing one or more block transform coefficients with Wavelet coefficients. A general architecture and class of transforms is disclosed including integer types having Wavelet features but which can be processed one block at a time. An exemplary integer, non-separable two-dimensional Wavelet Transform is disclosed to partner with a Walsh-Hadamard blocked transform to serve as the core for the apparatus then tailored to function as a DCT, DST or other signal transform.

A method and apparatus are disclosed herein for spatial sparsity induced temporal prediction. In one embodiment, the method comprises: performing motion compensation to generate a first motion compensated prediction using a first block from a previously coded frame; generating a second motion compensated prediction for a second block to be coded from the first motion compensated prediction using a plurality of predictions in the spatial domain, including generating each of the plurality of predictions by generating block transform coefficients for the first block using a transform, generating predicted transform coefficients of the second block to be coded using the block transform coefficients, and performing an inverse transform on the predicted transform coefficients to create the second motion compensated prediction in the pixel domain; subtracting the second motion compensated prediction from a block in a current frame to produce a residual frame; and coding the residual frame.

The method includes the following steps: first setting a target amplitude threshold for signal; after receiving analog sound signals, the analogy sound signals are amplified by amplifier in term of current gain of the amplifier, and then are converted into sampling point sequence of digital signal by A/D converter; when a post- process is made of the sampling point sequence, the amplitude counting module figures out the energy value of each sampling point in current sampling block and makes statistic for it to get a statistical value; the gain control module adjusts the gain of the amplifier by preset control mode in term of the statistical value and the target amplitude threshold. When the distance between user and microphone is changed, the invention can let listener hear a stable voice.

Methods and apparatus for performing near lossless-concatenated N-level constrained quantization Hadamard transform decoding are provided. Accordingly, the present invention provides a transform-based coding technique, where the coding loss introduced during repeated encoding and decoding is reduced to a substantially insignificant level. This is accomplished by employing a constrained quantization and inverse quantization operation in each level of encoding/decoding in the decoder. In this manner, the concatenation error between each level of a decoder is reduced to a substantially minimum level and the quantization error introduced during quantization operations, i.e., originally at the encoder and in each level of the decoder, is substantially reduced. Thus, the decoded bit stream that is output at the N-th level of the decoder is substantially the same as the original bit stream provided to the input of the encoder.

Image data processing techniques utilizing multiple processes operating on one or more processors of one or more computer systems can be used to efficiently rearrange or reparameterizing image data to form hologram element (hogel) images which can then be used to produce holographic stereograms. These techniques utilize matrix manipulation of portions of image data both within a single process, and across multiple processes typically executing on different processors, and each utilizing a subset of the overall set of image data.