37 results about "Average distortion" patented technology

A method and apparatus for temporally allocating bits between frames in a coding system such that temporal fluctuations are smoothed out. Namely, a picture quality is monitored on a frame by frame basis. An average distortion measure is derived from previous picture frames and that average is compared to the distortion measure of a current frame, where the result is used to effect bit budget allocation for each frame in an input image sequence.

A system for lossy compression of digital data for transmission to a remote location or to a storage medium and subsequently reconstructing the digital data includes an encoder which compares sequences of characters with an encoder database of data records to generate a compressed code. The compressed code includes pointer information relating to locations within the encoder database of data records corresponding within a given average distortion tolerance level per character to the sequences, and update information for the addition to the encoder database of new data records corresponding within the average distortion tolerance level per character to the sequences. The system also includes a decoder for receiving the compressed code, the receiver processing the compressed code to substantially reconstruct the digital data.

An automatic frequency controller includes a frequency offset estimating section that calculates phase distortion quantities and the average thereof from known signals contained in a received signal. The frequency offset estimating section obtains, from the average distortion quantity, signal powers corresponding to a plurality of candidate frequency offsets set at frequency offset estimation accuracy intervals in a frequency offset estimation range. The frequency offset estimating section looks at the signal powers through a frequency window with a frequency width corresponding to a transmission path state. This makes it possible to maximize the signal power of a frequency of a radio wave or radio waves corresponding to the transmission path state, and to place the radio wave or radio waves corresponding to the transmission path state as a frequency controlled object. This can improve demodulation accuracy. Fine adjustment of the candidate frequency offsets can improve the estimation accuracy of the frequency offset without changing the frequency offset estimation range.

The invention provides a transcoding method from H.264/SVC(scalable video coding) to H.264/AVC(advanced video coding) based on a video on demand system of P2PVoD, belonging to the field of video transcoding. With the adoption of SVC self-adapting transcoding, an SVC document is divided into independent multi-layer documents according to layers by a separator, before transcoding, a space layer and a quality layer are subjected to a self-adaption process according to the terminal ability, layers not needed are abandoned to enable the transcoding process to effectively reduce unnecessary time consumption, and the video quality matching with the ability of a client end is provided for the client end; with the adoption of a method combining a pixel region and an alternation region, time complexity is lowered, and error shift is effectively controlled; with the adoption of an encoding control optimized algorithm based on Lagrangian, when an average distortion function is being solved, a sum of absolute difference (SAD) is used for substituting a sum of squared difference (SSD), and the calculation complexity is simplified; and with the adoption of a processing mechanism by parallel threads based on GOP (group of pictures), the single-encoded GOP is processed by parallel threads, and thus the transcoding time is greatly reduced.

Audio signals are reproduced with consistent perception of total harmonic distortion even with varying spectral content of a particular audio signal without separately limiting different frequency bands within the audio signal. A distortion threshold representative of an amount of distortion to be allowed to be introduced by a power amplifier is determined in response to a frequency content of the audio signal. A distortion trigger compares a measured average distortion signal and the distortion threshold and reduces the controllable gain of the amplifier if the average distortion signal exceeds the distortion threshold.

A method encodes a video as video objects. For each candidate object, a quantizer parameter and a skip parameter that jointly minimizes an average total distortion in the video are determined while satisfying predetermined constraints. The average total distortion includes spatial distortion of coded objects and spatial and temporal distortion of uncoded objects. Then, the candidate objects is encoded as the coded objects with the quantizer parameter and the skip parameter, and the candidate objects is skipped as the uncoded objects with the skip parameter.

This invention relates to multicast rate optimization, particularly a method for controlling an encoder (1) in a communications system (3) including a plurality of receivers (2). The method includes partitioning the receivers (2) into at least one cell, and associating each cell with a specific rate that may be used to transmit signals to a receiver (2). According to the inventive method, uncertainties in estimates of conditions of the communications system (3) are taken into account by modelling the conditions, such as the average distortion perceived by the receivers (2), as the outcome of a stochastic variable, thereby accounting for uncertainties in the estimates of the conditions of the communications system (3). The invention also relates to an encoder associated with the method.

The invention provides a target equivalent rotation center estimation method for a double-base ISAR and relates to the field of radar signal processing technology. According to echoes received by a double-base radar, a one-dimensional distance image sequence is generated. Through grouping, a first image and a second image are generated and the observation view angle difference of the first image and the second image is calculated. According to a distortion angle calculating formula, a first average distortion angle and a second average distortion angle are calculated. According to the averagedistortion angles, the first image and the second image are corrected and are recorded as a first corrected image and a second corrected image. Further, according to the second corrected image and a rotation conversion formula, a rotation image is generated. Finally, according to the first corrected image and the rotation image, the correlation index of the first corrected image and the rotation image is calculated and the equivalent rotation center is determined. By adopting the technical scheme provided by the invention, the estimation precision of the equivalent rotation center is improved;through introduction of the average distortion angles, the application range of equivalent rotation center estimation is improved.

A method and an apparatus for estimating distortion due to quantization of data are described. A histogram with multiple frequency bands may be obtained for a set of coefficients to be quantized. Distortion due to quantization of the set of coefficients may be estimated based on the histogram and average distortions for the frequency bands of the histogram. The number of coefficients in each frequency band may be multiplied with an average distortion for the frequency band to obtain a per-frequency band distortion. The per-frequency band distortions for all of the frequency bands may be accumulated and scaled with a correction factor to obtain the estimated distortion. Each of the multiple frequency bands is corresponding to a unique quantization step of a set of quantization steps. Meanwhile, the starting value and the ending value of each frequency band are unique based on the respective quantization step correspondingly.

The invention discloses a non-invasive load identification method based on an improved particle swarm algorithm, and the method comprises the following steps: collecting electrical data of independentoperation of electric equipment, obtaining active power Pi, reactive power Qi and distortion power Di of the electric equipment during steady-state operation, and building a load feature library; acquiring data of electric equipment, performing missing value processing on the data, and calculating average active power Pj, average reactive power Qj and average distortion power Dj by adopting fastFourier transform; acquiring a state change condition of the electric equipment by setting a threshold value of the processed electric equipment data. According to the state change condition of the electric equipment, feature extraction of the electric equipment is carried out and load is identified through an improved particle swarm algorithm according to the extracted features of the electric equipment and the load feature library. According to the invention, the improved particle swarm algorithm and the fitness function are used to improve the accuracy of load identification and reduce thetime consumption of the algorithm.

The technique relates to a system and method for correcting geometric distortions in videos and images. To correct the one or more geometric distortions in videos, the frames of the original and distorted video are mapped at the beginning and then the features associated with the mapped frames which are insensitive to geometric distortions are identified. In case of correcting geometric distortions in images, frame mapping is not required and thus the process starts from identifying the features insensitive to geometric distortions in the original image and distorted image. Then, the geometric distortion parameters are identified from the mapped features. After that, a frame level and video level average distortion of the geometric distortion parameters are determined. Finally, the geometric distortions are corrected based on the frame level and video level average distortion value.

The invention discloses a panoramic video objective quality evaluation method based on space-time pipeline modeling, and the method comprises the steps: firstly adding a concept of time domain distortion according to a human eye visual mechanism, and building a video quality evaluation model based on a space-time pipeline; secondly, realizing the establishment of a space-time pipeline by a block search algorithm for motion estimation, the video content segmented spatially being associated front and back in time; the distortion of the space-time pipeline being decomposed into average distortionand time domain distortion, the average distortion being used for reasonably averaging the space distortion of blocks in the space-time pipeline through a recursive filter, and the recursive filter being used for consolidating the space-time pipeline distortion calculation by combining the frequency and amplitude of the distortion change gradient between the blocks; and finally, performing spatial domain pooling and time domain pooling calculation on all spatial-temporal pipeline distortions to obtain a final video quality score. By adopting the method provided by the invention, the accuracyof panoramic video objective quality evaluation can be greatly improved, so that the panoramic video objective quality evaluation better conforms to the subjective quality evaluation result of human eyes.

The invention relates to an L2 norm standardization and cosine theorem improvement-based elbow rule method, and belongs to the technical field of clustering analysis in data mining. The method comprises the steps of setting a range [Kmin-Kmax] of searching an optimal cluster number (an optimal K value) in a K-mean clustering algorithm; calculating average distortion degrees corresponding to Kmax-Kmin+1 clusters in the search range; and performing L2 norm standardization processing on the obtained Kmax-Kmin+1 average distortion degrees. Based on the K-mean clustering algorithm and elbow rules,the average distortion degrees obtained by the elbow rules are subjected to the L2 norm standardization processing and are further calculated by utilizing a cosine theorem, so that the optimal K valuein the search range is obtained; and the method can enable the obtained optimal K value to be more objective.

The invention discloses a method for acquiring a horizontal azimuth parameter codebook in a three-dimensional (3D) audio. The method comprises the following steps of: 1, determining the number n of codewords in a required codebook and the dimension number D of each codeword; 2, dividing a horizontal azimuth parameter in a horizontal azimuth parameter training set into D-dimensional vectors to obtain a training vector set, and forming n D-dimensional temporary codebooks by using the first n vectors; 3, dividing the vectors in the training vector set into n cells; 4, calculating subjective average distortion Dsp, comparing the subjective average distortion Dsp and a preset threshold error epsilon, determining a current temporary codebook is a final codebook if Dsp is smaller than epsilon, otherwise executing a step 5; and 5, reselecting a new temporary codebook, and repeating the steps 3 to 4. When the codebook acquired by the method is applied to horizontal azimuth parameter quantification, the whole subjective quantification performance can be improved.

The invention relates to a high-entropy alloy lattice distortion calculation method based on an atom occupation ordering behavior. The method comprises the following steps: S1, constructing a corresponding thermodynamic model; S2, calculating discrete values of the Gibbs free energy thermodynamic data of the end group compounds and the elementary elements in the high-entropy alloy; S3, constructing a thermodynamic database of the high-entropy alloy end-group compound; S4, calculating to obtain the occupation fractions of various elements in the high-entropy alloy on sublattices under the conditions of given components and temperature; s5, constructing a structure model of actual distribution of atoms in the high-entropy alloy; s6, obtaining a structure model after structure optimization; and S7, according to the structure model subjected to structure optimization, substituting the structure model into a preset lattice distortion formula, and calculating to obtain the total distortion amount, the average distortion amount and the relative lattice distortion amount of the high-entropy alloy. According to the method, the lattice distortion effect of the high-entropy alloy is quantitatively calculated.

The invention discloses a method for correcting signal distortion. The method consists of the steps of: scanning a bar-space equal-width test barcode and using the scanned width value of each bar-space acquired by scanning the test barcode as a distortion width value; acquiring the average distortion width value of the bar-spaces of the test barcode according to the distortion width value of each bar-space of the test barcode; using the average distortion width value as the reference value to acquire the deviation value of the distortion width value and the average distortion width value and correcting the acquired scanning width value of the scanned barcode according to the deviation value. The invention also discloses a laser barcode scanning platform. By means of this invention, the distortion of the barcode signal transformed from a barcode width value is corrected, the code reading performance of the laser barcode scanning platform is enhanced, and it is not necessary to write control programs for the laser heads of each laser barcode scanning platform equipment; in the meantime, the requirements for laser head precision and manufacturing technique are lowered, and the production cost of laser barcode scanning platform is lowered.