Concatenated convolution framelets in audio compression

Student thesis: Master thesis (including HD thesis)

  • Thomas Rune Hansen
  • Hoza Benjamin Maniragaba
  • Mathias Bach Pedersen
4. semester, Mathematical Engineering, Master (Master Programme)
This project concerns convolution framelets, [Yin et al., 2017], a recently proposed class of redundant tight frames. Specifically, the use of convolution framelets in audio compression is explored. In order to adapt convolution framelets to the problems of compression, we propose methods for controlling the degree of redundancy. Rather than using a single convolution framelet with a high degree of redundancy, a concatenation of less redundant convolution framelets is used. This allows for the use of multiple patch sizes, at the cost of having fewer patches of each size. The compression scheme in this project is inspired by an audio coding scheme proposed by [Ravelli et al., 2008]. The compression scheme consists of finding a sparse set of frame coefficients, and coding these coefficients. To find sparse coefficients, the orthogonal matching pursuit algorithm, [Foucart and Rauhut, 2013], is used. The coding algorithm is inspired by that in [Ravelli et al., 2008], which relies on bitplane run-length coding, and uses an interleaving scheme. The compression scheme is tested on a set of music excerpts, and the resulting quality, estimated by perceptual evaluation of audio quality, are compared to an MP3 coder and the non-psychoacoustic results in [Ravelli et al., 2008]. This comparison shows that our compression scheme does not perform as well for low bit rates.
Publication date7 Jun 2018
Number of pages70
ID: 280478734