Codificação perceptiva de áudio por meio de decomposições atômicas em exponenciais complexas

Abstract

The atomic decomposition of signals by algorithm of the class “Matching Pursuit” (MP) has been applied in audio compression. Literature review suggests that, the use of psychoacoustic criteria allows a more compact representation of the signal, without loss of perceived quality. This work presents the implementation of an analysis system by synthesis of audio signals using MP associated with the use of psychoacoustic global masking threshold, inspired by MPEG layer I, as well as Complex Exponential Dictionaries (DEC). For the compression of the signal, we used the optimization of rate-distortion by operational curves, adjusting the Lagrange multiplier. The performance of the compression method for different types of signals is evaluated by an objective measurement standardized by the International Telecommunications Union (ITU), the PEAQ (Perceptual Evaluation of Audio Quality) based on the bit rate per sample, obtaining satisfactory results.

Keywords

• matching pursuit. atomic decomposition of signals. psychoacoustic