Codebook

About: Codebook is a research topic. Over the lifetime, 8492 publications have been published within this topic receiving 115995 citations.

Multipath Search Coding of Stationary Signals with Applications to Speech

Abstract: This paper deals with the application of multipath search coding (MSC) concepts to the coding of stationary memoryless and correlated sources and of speech signals at a rate of one bit per sample. We have made use of three MSC classes: 1) codebook coding (vector quantization), 2) tree coding, and 3) trellis coding. This paper explains the performances of these coders and compares them both with those of conventional coders and with rate-distortion bounds. Figs. 2 and 3 demonstrate the potentials of MSC coding strategies. The paper reports also on results of MSC coding of speech, where both the strategy of adaptive quantization and of adaptive prediction were included in coder design.

Exploring relations of visual codes for image classification

Abstract: The classic Bag-of-Features (BOF) model and its extensional work use a single value to represent a visual code This strategy ignores the relation of visual codes In this paper, we explore this relation and propose a new algorithm for image classification It consists of two main parts: 1) construct the codebook graph wherein a visual code is linked with other codes; 2) describe each local feature using a pair of related codes, corresponding to an edge of the graph Our approach contains richer information than previous BOF models Moreover, we demonstrate that these models are special cases of ours Various coding and pooling algorithms can be embedded into our framework to obtain better performance Experiments on different kinds of image classification databases demonstrate that our approach can stably achieve excellent performance compared with various BOF models

Improved matching pursuits image coding

Abstract: This paper reports improvements in compression of both inter- and intra-frame images by the matching pursuits (MP) algorithm. For both types of image, applying a 2D wavelet decomposition prior to MP coding is beneficial. The MP algorithm is then applied using various separable ID codebooks. MERGE coding with precision limited quantization (PLQ) is used to yield a highly embedded data stream. For inter-frames (residuals) a codebook of only 8 bases with compact footprint is found to give improved fidelity at lower complexity than previous MP methods. Great improvement is also achieved in MP coding of still images (intra-frames). Compared to JPEG 2000, lower distortion is achieved on the residual images tested, and also on intra-frames at low bit rates.

CELP vocoder with efficient adaptive codebook search

Abstract: A new method for Code Excited Linear Predictive (CELP) coding of speech reduces the computational complexity by removing a convolution operation from a recursive loop used to poll the adaptive code book vectors. In a preferred embodiment, an impulse function of a short term perceptually weighted filter is first convolved with perceptual weighted target speech and the result cross-correlated with each vector in the codebook to produce an error function. The vector having the minimum error function is chosen to represent the particular speech frame being examined.

Method and apparatus in a wireless communication system for compressing and decompressing messages generated by a plurality of applications

Abstract: A server (112) sends (604) selected codebooks (226) and application identifiers (228) to be associated with the codebooks, to a client (122) in preparation for communicating messages. The client receives and stores (606) the selected codebooks and application identifiers. Subsequently, the server, in response to having a message to send to the client, compresses (708) the message according to a codebook associated with an application generating the message, and transmits (710) the message and an application identifier to the client. The client, in response to receiving the message and the application identifier, identifies (714), from the application identifier, the application to receive the message and, hence, the codebook associated with the application, to use for decompressing the message. The client then decompresses (716) the message according to the codebook.