Teaching page G. Sleijpen

Fourier Theory and Wavelets

Course code: WISM453

CONTENT

An introduction will be given to the theory of Wavelets and Fourier transforms, and their applications.

The course will be divided in two parts.

The first part is an introduction to Fourier analysis, including the discrete Fourier transform, the fast Fourier transform and applications such as computerized tomography.

In the second part the focus will be on wavelets including the Haar wavelets, multi-resolution analysis, Daubechies wavelets, discrete wavelet transforms and applications to signal processing and data compression.

AIM

The student will understand the basic theory and is familiar with the advantages and disadvantage of Fourier and Wavelet transforms. He/she can read the technical literature in which these transforms play a crucial role. In practical situations, he/she will know when these transforms will be useful and he/she can identify the most appropriate transform. He/she can analyze and solve practical problems using these transforms and can employ standard software (based on fast Fourier and fast wavelet transform).

EDUCATIONAL FORM

Mixture of standard lectures, exercise class and computer laboratory.

GRADING

Report plus exercises. More details

LOCATION, TIME, Academical year 2013-2014

Location: Buys Ballot Lab, room 071 (BBL071).
    Princetonplein 5 (Google maps),
    De Uithof, 3584 CC Utrecht
Time: 15 lectures on the Mondays, 10:00-12:45
Period: 3 + 4 February 3, 2014 (week 6) - May 26, 2014 (week 22)
There will be no lecture in the weeks 17 (April 21 [Easter Monday]) and 19 (May 5 [Liberation Day]).

COURSE MATERIAL

Course material will be provided during the course or can be downloaded from this page (see below).



Fourier Theory

  • Schedule

    The schedule below for lectures to come is from the previous course. We will roughly follow this schedule in the present course. Schedule as well as transparencies and handouts will be updated when updates are available (as a rule, before the lecture).

    A printed version of the Lecture Notes will be on sale from Aes-kwadraat.

    For Lecture Notes, Transparencies, etc., see the Documentation page (limited access).
    Number of Chapters and exercises refer to the Lecture Notes.
    • Lecture 1. Discussed in class: Introduction (see transparancies), Chapter 1, up to Paragraph 1.8, exercise 1.3 of the Lecture Notes plus the exercises on transparencies.
      Assignments: Ex. 1.8, 1.13 and 1.16.
      Please, read the Paragraphs 1.9 and 1.10 at home.
    • Lecture 2. Discussed in class: Chapter 2, plus the exercises on transparencies.
      Assignments: Ex. 2.6 and 2.8; visit the website on `Hearing Fourier Series' mentioned on the Fourier Documentation page (limited access) .
    • Lecture 3. Discussed in class: Chapter 3, 3.1-3.16, Chapter 7, 7.1-7.2, Exercises 3.2 and 1.8.
      Assignments: Ex. 3.3, 3.4 (Hint: use the results of Ex. 3.2), and 3.9 (for 3.9, it might be helpful to read section 2.6 first).
    • Lecture 4. Discussed in class: Exercises 3.3, 3.9, 3.11, Chapter 3.16-3.17. Section 7.D
      Assignments: Ex. 3.16 and 3.18.
    • Lecture 5. First computer session (see “Computer session I” at the end of the Lecture Notes). In room BBL103
    • Lecture 6. Discussed in class: Chapter 4 and 5.
      Assignments: Ex. 5.3 and 5.5 (a)-(d).
    • Lecture 7. Discussed in class: Ex. 5.3, 5.5, Chapter 7,A, Chapter 6.
      Assignments: Ex. 6.6, 6.14.
    • Lecture 8. Discussed in class: Chapter 8.A, 7.C, 8.B and 8.C.
      Assignments: 8.7, 6.4, 6.5, and 6.12.
    • Lecture 9. Second computer session.
      - Finish the assignments in the Lecture notes in "Computer session I" (convergence behavior of Fourier series).
      - Do the assignments on Digital Spectral Analysis.
      Assignments: 6.17 and 8.10.
  • Documentation (limited access)
  • Computer sessions on Fourier transforms
    To do: follow the instructions in the text, make notes and discuss these notes with Gerard.
    • First session: convergence behavior of Fourier series
    • Second session: digital spectral analysis


Wavelets

  • Schedule

    The schedule below is from the previous course. We will roughly follow this schedule in the present course. Schedule as well as transparencies and handouts will be updated when updates are available (as a rule, before the lecture).

    For Transparencies, exercises, etc., see the documentation page (limited access)
    Number of an Exercise refer to the an exercise in the exercise set.
    • Lecture 10. Introduction wavelets.
      - We discussed the first 113 transparencies
      Assignments: Ex. 1.1 and 1.4
    • Lecture 11. Wavelets, filters and block Toeplitz matrices.
      - We discussed the transparencies 115-246
      Assignments: Ex. 3.2 and 3.3
    • Lecture 12. Splines, approximation quality.
      - We discussed the transparencies 247-351
      Assignments: Ex. 4.4
    • Lecture 13. Conditioning, Existence, smoothness, orthogonality.
      - We discussed the transparencies 352-436
      Assignments: Ex. 5.1 and 5.3 (you may use Riesz' Lemma of Ex. 5.2).
    • Lecture 14. Computer session on Wavelets.
  • Documentation (limited access)
  • Computer sessions on wavelets.
    To do: follow the instructions in the text, make notes and discuss these notes with Arno or Gerard.
    Exercises by Arno Swart based on material from Jeroen de Waard, Stefan van der Baan, Martijn Pistorius, Sander de Putter
    • First exercise: Noise filtering with wavelets
    • Second exercise: Comparison of wavelets and Fourier
    • Third exercise: Audio compression with wavelets


Final Assignment

Write a report on one of the following subjects. You can select a practical subject, or a pure theoretical one, or a literature study.
Before you start working on one of these subjects, talk to the teacher first.
One student per report.
  • Computerized Tomography
    To do: Write a computer program (either C or Matlab) and a report on Computerized Tomography. In this report, you should give theoretical background and discuss the effect of discretizations (and rounding errors) on the quality of back transform.
    • Use the questions in the text (ps.gz) for inspiration. See also the documentation page.
    • There is a small Matlab program, Images.m (tar.gz  *), that may help you to generate image matrices.
      Run this program in Matlab 6 (or higher). This program may be helpful if you are programming in Matlab but also if you program in C or C++.
    • Files to get started:
      • Matlab files (tar.gz  *) (for matlab programmers).
        This package contains stripped versions of a working package. For comparison convenience, pictures as produced by this operational version have been displayed here.
      • C routines (tar.gz  *) (for C programmers).
  • An introduction JPEG-2000-like compression using MATLAB and its wavelet toolbox.
    To do: Write a report; go to the Wavelet & FFT resources page for instructions.
    Exercise by Arno Swart
  • Theoretical subject. Write a paper on Theorem 2.4 of the Lecture notes on Fourier Theory. The report should contain a proof (the proof is scattered among a number of exercises in the Lecture notes [like Ex.2.2--2.24 and Ex.6.17-6.20]), but also motivations, explanations, examples, background information. The presentation of the arguments should be well structured (lemmas, theorems, etc.) and motivated.
  • Literature study. Write a report or design a Matlab session on a subject from applications in which Fourier theory and/or wavelet transform plays a crucial role. The application should require some extension to theory as presented in the course (‘new’ aspects).
    The report should be a small appendix to the lecture notes (5 to 10 pages. Chapter 9 in the Lecture Notes forms an example). In particular, the notation should match the one of the Lecture Notes. It should not double results from the lecture notes: in such a case, a cross-reference to the appropriate result in the Lecture Notes suffices. Provide the background information from the application as concise as possible, elaborate on ‘new’ aspects form Fourier Theory/ wavelets. The focus should be on subjects from the course. If the discussion on certain aspects is going to be to technical, consider to put these details in an exercise (separate from the report, also hand in the solution to these exercises).
    For the Matlab session, provide some background material, write the exercises (questions), and the Matlab code (on a separate paper, give the solutions).
    Note. One author per report, but here is a possibility for a joint project. One person can work on the report, another can design a Matlab session that matches the report.
    Examples.
    • MRI
    • MP3 compression
    • Signal analysis in Geophysics
    • ...
    It is appreciated if you come up with a suggestion by yourself.


Some Useful Links



*   To unwrap FILE.tar.gz:
    > gunzip FILE.tar.gz
    > tar xvf FILE.tar





  © Gerard L. G. Sleijpen   <G.L.G.Sleijpen@uu.nl>
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