188 results about "Second quantization" patented technology

A method and apparatus for performing video compression and decompression using dynamic quantization and/or encoding. According to one aspect of the compression method, an image is recursively filtered into its constituent components each represented by a matrix of coefficients. Next, the level of correlation of a first of the matrices of coefficients is determined. Based on the level of correlation of this first coefficient matrix, one of a first quantization technique and a second quantization technique is selected. The first coefficient matrix is then quantized using the selected quantization technique.According to another aspect of the compression method, an image is digitally filtered into its constituent components, each represented by a matrix of coefficients. At least certain matrices are quantized to generated a first quantized matrix. The first quantized matrix is then recursively divided until the first quantized matrix or each of the resulting submatrices is sufficiently dense or sufficiently sparse. Each of the sufficiently dense matrices are encoded using a first technique, while each of the sufficiently sparse matrices are encoded a second technique.

Provided is an apparatus and method for encoding and decoding using alternative transform units according to the correlation of residual signals. The video encoding apparatus includes a first transforming unit for performing discrete cosine transform (DCT), first quantization, first inverse quantization, and inverse DCT on a block basis onto residual coefficients generated after intra frame prediction or inter frame prediction; a second transforming unit for performing discrete sine transform (DST), second quantization, second inverse quantization, and inverse DST on a block basis onto the residual coefficients; a selecting unit for selecting one having a high compression rate between the first and second transforming units for each block through performing rate-distortion optimization; and a flag marking unit for recording information about the selected transforming unit at a flag bit provided on a macroblock basis.

A system and method for generating a second reduced size digital image from a first digital image, the method including iteratively compressing the first digital image to an extent determined by a quality measure comprising at least a blockiness measure quantifying added artifactual edges along coding block boundaries of the second image and/or use of a quantization matrix generated by computing a weighted average of the quantization matrix of the first digital image and a scaled second quantization matrix.

A video encoding method includes encoding n pictures included in a video image using a first quantization parameter, calculating first number-of-encoded-bits information indicating number of encoded bits of every picture type, multiplexing a set frame rate by an average first-number-of-encoded-bits per picture calculated from the first-number-of-encoded-bits information to obtain a first bit rate, encoding the n pictures using a second quantization parameter, calculating second number-of-encoded-bits information indicating number of encoded bits of every picture type, multiplexing the set frame rate by an average second number-of-encoded-bits per picture calculated from the first-number-of-encoded-bits information to obtain a second bit rate, calculating a third quantization parameter, using the first bit rate, first quantization parameter, second bit rate, second quantization parameter and target bit rate, and performing the rate control using the third quantization parameter as an initial value.

A video encoder controlling rate of each frame in a current frame set (Group of Picture, GOP), and method thereof. The video encoder comprises a frame grouping device, a GOP initialization device, and a GOP encoding device. The frame grouping device allocates a target bit budget R_GOP to the current frame set. The GOP initialization device is coupled to the frame grouping device, and estimates a first quantization parameter QP₁ based on the target bit budget R_GOP and complexity of the current frame set. The GOP encoding device is coupled to the GOP initialization device, and encoding a frame in the current frame set with the second quantization parameter QP₂ to generate output data.

A plurality of macroblocks constituting coded data are inverse quantized using a first quantization matrix that is used when coding a picture, to obtain a plurality of sets of coefficient data. The first quantization matrix is converted to a second quantization matrix using a first conversion value and a second conversion value, where the first conversion value is for converting a low frequency coefficient corresponding to a frequency lower than a predetermined frequency among a plurality of coefficients shown by the first quantization matrix, and the second conversion value is for converting a high frequency coefficient among the plurality of coefficients and is larger than the first conversion value (Step S408). When the second quantization matrix is a matrix for increasing a coding rate of the coded data, a converted scale is calculated by multiplying a quantization scale corresponding to at least one macroblock by β1 (≧1). At least one part of the plurality of sets of coefficient data is quantized using the second quantization matrix and a calculated converted scale that corresponds to a macroblock corresponding to the at least one part of the plurality of sets of coefficient data.

A transducer amplification circuit may include a preamplifier circuit with a signal input receiving a transducer signal to provide an amplified transducer signal comprising audible frequency components and ultrasonic frequency components. The transducer amplification circuit may include a first sigma-delta modulator configured to sample and quantize the amplified transducer signal to generate a first digital transducer signal comprising a first quantization noise signal. The first sigma-delta modulator may include a first noise transfer function having a high pass response in at least a portion of an audible frequency range to push the quantization noise signal to ultrasonic frequencies. A second sigma-delta modulator is configured to sample and quantize the amplified transducer signal to generate a second digital transducer signal comprising a second quantization noise signal. The second sigma-delta modulator may include a second noise transfer function with a magnitude minimum placed at the ultrasonic frequencies.

Video signal coding apparatus includes: a quantization unit which quantizes, using coefficient values in a first quantization matrix, a luminance signal of each of a first picture and a second picture coded after the first picture, and quantizes, using coefficient values in a second quantization matrix, a chrominance signal of each of the first picture and the second picture; a code amount obtainment unit which obtains a luminance code amount and a chrominance code amount of each of the first picture and the second picture; a rate calculation unit which calculates a rate of the chrominance code amount with respect to the luminance code amount for each of the first picture and the second picture, obtained by the code amount obtainment unit; and a rate control unit which changes a coefficient value of at least one of the first matrix and the second matrix used in quantizing the second picture, before the quantization unit quantizes the second picture, so that the rate for the second picture becomes smaller than the rate for the first picture.

A method of optimizing an encoded video stream comprising one or more video frames, each video frame comprising a plurality of macroblocks, each macroblock comprising a plurality of pixels. The method includes receiving an encoded macroblock, decoding the encoded macroblock, and extracting a first quantization parameter. The first quantization parameter corresponds to quantization settings originally used for compressing the encoded macroblock. The method also includes computing a second quantization parameter based at least in part on the first quantization parameter, re-encoding the decoded macroblock based on the second quantization parameter, and providing the re-encoded macroblock.

A time-to-digital converter includes low and high resolution time-to-digital converters for providing both high resolution and wide measurement range. The low resolution time-to-digital converter measures a time difference between first and second signals with a first quantization step. The high resolution time-to-digital converter measures the time difference between the first and second signals with a second quantization step that is smaller than the first quantization step. The low resolution time-to-digital converter has a wider measurement range than the high resolution time-to-digital converter

A rate conversion apparatus 10 includes a quantization parameter setting unit 107 and a rounding threshold value setting unit 108. The quantization parameter setting unit 107 determines a quantization parameter change amount according to a code amount of encoded data output from a variable length encoding unit 109 and a target code amount. The quantization parameter setting unit 107 adds a first quantization amount used in an image before conversion to the quantization parameter change amount, to generate a second quantization parameter to be used in re-quantization processing in a quantization unit 105. The rounding threshold value setting unit 108 sets the rounding threshold value according to the quantization parameter change amount. The quantization unit 105 performs re-quantization using the second quantization parameter and the rounding threshold value.

An encoding apparatus and method prevents image deterioration generated by repeatedly performing encoding and decoding by using a quantization matrix for quantization which is different from a quantization matrix for inverse quantization. In the encoding apparatus, a matrix selector selects a first quantization matrix in accordance with the complexity of an encoded picture pattern, and supplies a quantizer with information on the selected first quantization matrix. A matrix unit rewrites, by information on a second quantization matrix, the information described in an encoded stream output from a variable length code unit so that a quantization matrix to be used for inverse quantization is a second quantization matrix different from the first quantization matrix.

A cascaded analog-to-digital converter includes a first stage delta-sigma modulator to quantize an input signal and produce a first quantization error signal. A second, coupled multi-stage delta-sigma modulator quantizes less significant bits of the input signal, wherein a first quantization stage is coupled to the first quantization error signal to quantize the next most significant bits of the input signal and produce a second quantization error signal. A second quantization stage is coupled to the second quantization error signal to quantize the least significant bits of the input signal and produce a third quantization error signal. A noise-shaping filter is coupled to the third quantization error signal, the output of which is subtracted from the first quantization error signal to produce said input of the first quantization stage.

An apparatus for image coding using tree-structured vector quantization based on a wavelet transform and a method therefor are provided. The apparatus for image coding using a tree-structured vector quantization based on wavelet transform has a wavelet transform unit, a vector construct unit, an error vector unit, a scan unit, a first quantization unit and a second quantization unit. The wavelet transform unit wavelet transforms an input image signal. The vector construct unit constructs vectors, each having a tree structure in a different direction, using the wavelet transformed result. The error vector generation unit generates a plurality of error vectors by setting one of the vectors as a basic vector and performing a calculation on each of the vectors remaining with respect to the basic vector. The scan unit scans the coefficients of each of the basic vector and error vectors in a different direction. The first vector quantization unit generates a first codebook for the basic vector scanned in the scan unit, quantizes the scanned basic vector using the first codebook, and outputs the quantization result as the index of the first codebook. The second vector quantization unit generates a second codebook for the error vectors scanned in the scan unit, quantizes the scanned error vectors using the second codebook, and outputs the quantization results as the indices of the second codebook. According to the apparatus and method, the advantages of wavelet vector quantization and zerotree-coding are maximized so that the size of a codebook is reduced and the coding performance is improved.

Provided is an encoding method capable of reducing a blocking phenomenon that occurs when moving-images are encoded and decoded. The method includes: performing a first encoding operation on an input image using a first quantization coefficient; generating a reconstructed image of the encoded image; calculating a difference between corresponding partial images of the reconstructed image and the input image; and performing a second encoding operation on the calculated difference using a second quantization coefficient smaller than the first quantization coefficient. Using the second encoded difference, a decoding unit can reconstruct an image of a block boundary portion more elaborately with a small number of bits, thereby significantly reducing the blocking phenomenon in the decoding operation.

Provided is a process including: segmenting a frame of video into a plurality of blocks; transforming each of the blocks to form respective transform matrices; for a given transform matrix, quantizing the given transform matrix with a first quantization matrix to form a first quantized transform matrix; quantizing the given transform matrix a second time with a second quantization matrix to form a second quantized transform matrix; and forming a sequence of hybrid quantized transform matrix values from part of the first quantized transform matrix and part of the second quantized transform matrix.

The present disclosure relates to a pre-5^th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4^th-Generation (4G) communication system such as Long Term Evolution (LTE). A feedback transmission method for a receiving device in a multiple input multiple output system according to one embodiment comprises: a step of measuring channel state information; a first quantization step of quantizing the channel state information using a first codebook; a second quantization step of quantizing the channel state information using second and third codebooks which are different from the first codebook; and a step of feeding back the channel state information on the basis of a selection result of one of the first and second quantization steps.

An image decoding apparatus decodes a bit stream generated by coding an image and decodes coded data included in the bit stream and corresponding to a target block to be decoded in the image. The apparatus includes a first determining unit configured to determine whether the target block is prediction-coded or palette-coded; a second determining unit configured to determine whether or not a pixel in the target block is escape-coded if the first determining unit determines that the target block is palette-coded; and a first decoding unit configured to decode the target block by using a second quantization parameter different from a first quantization parameter if the second determining unit determines that the pixel is escape-coded. The first quantization parameter is used to decode the coded data in a case where the first determining unit determines that the target block is prediction-coded.