Linear predictive coding

About: Linear predictive coding is a research topic. Over the lifetime, 6565 publications have been published within this topic receiving 142991 citations. The topic is also known as: Linear predictive coding, LPC.

Speech recognition method including biased principal components

Abstract: A speech recognition method and apparatus employ a speech processing circuitry for repetitively deriving from a speech input, at a frame repetition rate, a plurality of acoustic parameters. The acoustic parameters represent the speech input signal for a frame time. A plurality of template matching and cost processing circuitries are connected to a system bus, along with the speech processing circuitry, for determining, or identifying, the speech units in the input speech, by comparing the acoustic parameters with stored template patterns. The apparatus can be expanded by adding more template matching and cost processing circuitry to the bus thereby increasing the speech recognition capacity of the apparatus. The speech processing circuitry establishes overlapping time durations for generating the acoustic parameters and further employs a sinc-Kaiser smoothing function in combination with a folding technique for providing a discrete Fourier transform. The Fourier spectra are transformed using a biased principal component analysis which optimizes the across class variance. The template matching and cost processing circuitries provide distributed processing, on demand, of the acoustic parameters for generating through a dynamic programming technique the recognition decision.

Pitch lag estimation using frequency-domain lowpass filtering of the linear predictive coding (LPC) residual

Abstract: A pitch estimation device and method utilizing a multi-resolution approach to estimate a pitch lag value of input speech. The system includes determining the LPC residual of the speech and sampling the LPC residual. A discrete Fourier transform is applied and the result is squared. A lowpass filtering step is carried out and a DFT on the squared amplitude is then performed to transform the LPC residual samples into another domain. An initial pitch lag can then be found with lower resolution. After getting the low-resolution pitch lag estimate, a refinement algorithm is applied to get a higher-resolution pitch lag. The refinement algorithm is based on minimizing the prediction error in the time domain. The refined pitch lag then can be used directly in the speech coding.

Speech synthesis method, speech synthesis system, and speech synthesis program

Abstract: A speech synthesis system stores a group of speech units in a memory, selects a plurality of speech units from the group based on prosodic information of target speech, the speech units selected corresponding to each of segments which are obtained by segmenting a phoneme string of the target speech and minimizing distortion of synthetic speech generated from the speech units selected to the target speech, generates a new speech unit corresponding to the each of the segments, by fusing the speech units selected, to obtain a plurality of new speech units corresponding to the segments respectively, and generates synthetic speech by concatenating the new speech units.

Classified adaptive prediction and entropy coding for lossless coding of images

Abstract: Natural images often consist of many distinct regions with individual characteristics. Adaptive image coders exploit this feature of natural images to obtain better compression results. In this paper, we propose a classification-based scheme for both adaptive prediction and entropy coding in a lossless image coder. In the proposed coder, blocks of image samples (in the PCM domain) are classified to select an appropriate linear predictor from finite set of predictors. Once the predictors have been determined, the image is DPCM coded. A second classification is then performed to select a suitable entropy coder for each block of DPCM samples. These classification schemes are designed using two separate clustering procedures which attempt to minimize the bit-rate of the encoded image. The coder was tested on a set of monochrome images and was found to produce very promising results.