OUTLINE OF THE UPCOMING BOOK...

Chapters currently available for free download in PDF format indicated by asterisk (*)

  • CHAPTER 1* - Preview of Wavelets, Wavelet Filters and Wavelet Transforms in Digital Signal Processing (DSP)
    What is a Wavelet?
    What is a Wavelet Filter and how is it Different from a Wavelet?
    The Value of Transforms and Examples of Everyday Use
    Short-Time Transforms, Sheet Music, and a First Look at Wavelet Transforms
    An Example of the Fast Fourier Transform (FFT) with an Embedded Pulse Signal
    Examples Using the Continuous Wavelet Transform
    A First Glance at the Undecimated Discrete Wavelet Transform (UDWT)
    Why the UDWT is Sometimes Called a “Redundant” DWT (RDWT) or “A’ Trous” (“with holes”)
    A First Glance at the Conventional Discrete Wavelet Transform (DWT)
    Examples of Use of the Conventional DWT
    Summary
  • CHAPTER 2* - Walk-Through of the Continuous Wavelet Transform (CWT) using the Haar Wavelet Filters
    Simple Scenario: Comparing Exam Scores Using the Haar Wavelet
    Above Comparison Process Seen as Simple Correlation or Convolution
    Display of the Continuous Wavelet Transform (CWT) of the Exam Scores Using the Haar Wavelet Filter
    Summary
  • CHAPTER 3* - Walk-Through of the Undecimated Discrete Wavelet Transform (UDWT) using the Haar Wavelet Filters
    Single-Level UDWT of Exam Data
    Frequency Allocation of a Single-Level UDWT
    Multi-Level UDWT
    Frequency Allocation of a Multi-Level UDWT
    The Haar UDWT as a Moving Averager
    Summary
  • CHAPTER 4* - Walk-Through of the Conventional (Decimated) Discrete Wavelet Transform (DWT) using the Haar Wavelet Filters
    Single-Level (Decimated/Downsampled) Discrete Wavelet Transform (DWT) of Exam Data
    Additional Example of Perfect Reconstruction in a Single-Level DWT
    Compression and Denoising Example using the Single-Level DWT
    Multi-Level Conventional (Decimated) Discrete Wavelet Transform (DWT) of Exam Data using Haar Wavelet Filters
    Frequency Allocation in a (Conventional, Decimated) DWT
    Final Approximations and Details and How to Read the DWT Display
    Denoising Using a Multi-Level DWT
    Summary
  • CHAPTER 5 - Filters from Wavelets—Obtaining Real-World Discrete Filters from Wavelets with Explicit Mathematical Expressions (“Crude Wavelets”)
    Review of Familiar DSP Truncated Sinc Function
    Adding More Points at the Ends for Better Filter Performance
    Adding More Points by Interpolation for Lower Cutoff Frequency
    Multi- Point “Stretched Filters” Derived from Explicit Mathematical Equations of “Crude” Wavelets
    Mexican Hat Wavelet and Morlet Wavelet as Examples of Stretched Filters
    How the Passband is Changed due to Stretching
    CWT Display of the Results of Using these Stretched Filters on a Split-Sine Test Signal
    Summary
  • CHAPTER 6 - Wavelets from Filters—Fixed Length Filters to Continuous Wavelet Estimation to Variable Length Filters
    Interpolation of Original Wavelet Filter by Upsampling and LowPass Filtering
    Building an Estimation (Approximation) of a “Continuos” Wavelet Function
    Building a Filter of Any Desired Length from the “Continuous” Estimation
    Example of Building a 258-Point “Continuous” Haar Wavelet Function from the 2-Point Filter
    Building a Haar Filter of Arbitrary Length from the 258 Point Estimation
    Numerical Integration to Handle the Discontinuities in the Haar
    Frequency Response of the Original and Stretched Haar Filters
    Haar and Shannon Wavelet Filters as “Duals” of Time/Frequency Precision
    Example of Building a 768-Point “Continuous” Daubechies 4 (Db4) Wavelet Function from the 4-Point Filter
    Building a Db4 Wavelet Function Filter of Arbitrary Length from the 768 Points
    Perfect Overlay of Four Equispaced Db4 Filter Points on the “Continuous” Wavelet Estimation
    Two Additional Equispaced Zero Points (at the end) Complete the Overlay
    Physical Meaning of the “Length” of a Wavelet
    Frequency Response of the Original and Stretched Db4 Wavelet Function Filters
    Perfect Overlay of the Db6, Db8, Coiflet, and Biorthogonal Filter Points and Zero Points on their Estimations
    Summary
  • CHAPTER 7 - Overview and Comparison of the Four Major Types of Wavelet Transforms
    Advantages and Disadvantages of the Continuous Wavelet Transform (CWT)
    Stretching the Wavelet—The Undecimated Discrete Wavelet Transform (UDWT)
    Shrinking the Signal Instead—The Conventional (Downsampled) Discrete Wavelet Transform (DWT)
    Decomposing More of the Signal—The Wavelet Packet Transform (WPT)
    The Problem of Aliasing Caused by Downsampling in the WPT and the Conventional DWT
    How to Cancel Out the Aliasing —If Done Correctly
    Summary
  • CHAPTER 8 - Perfect Reconstruction Quadrature Mirror Filters (PRQMF) and their Relationships
    The Four PRQMF Filters—HighPass (HP) Decomposition, HP Reconstruction, LowPass (LP) Decomposition and LP Reconstruction
    Close Relationships of the Four PRQMF Filters to Each Other
    Building the Wavelet Function from the HP Reconstruction Filter
    Building the Scaling Function from the LP Reconstruction Filter
    Summary
  • CHAPTER 9 - Another Look at the DWT and UDWT Displays—Important Relationships
    DWT and UDWT Displays of a Split Sine Signal with the Db4 Scaling Function
    DWT and UDWT Displays of a Split Sine Signal with the Db4 Wavelet Function
    DWT and UDWT Displays of a Decaying Exponential Signal with the Haar Scaling Function.
    DWT and UDWT Displays of a Decaying Exponential Signal with the Haar Wavelet Function
    Summary
  • CHAPTER 10 - Reconciling the DWT and UDWT to the CWT—All are Basic Correlations
    Locations on the Signal Diagram where the UDWT and the CWT are Exactly the Same Using Haar Wavelet Filters
    Locations on the Signal Diagram where the Conventional DWT and the CWT are the Same When Downsampled Using Haar Wavelet Filters
    Locations on the Signal Diagram where the Conventional DWT and the CWT are Very Similar Using Four-Point Db4 Filters
    Summary
  • CHAPTER 11 - Looking at the Major Wavelet Families—Their Strengths, Weaknesses, and Popular Uses
    Vanishing Moments
    Time vs. Frequency Resolution
    Orthogonality
    Symmetry
    Suitability for use in a DWT or UDWT
    Table of Desired Properties and Best Choice of Wavelet
    The “Sport of Basis Hunting” and Best Basis
    The Lifting Scheme
    Summary
  • CHAPTER 12 - Case studies of Applications of Wavelets to Real-Life Problems
    Removing White Noise Using the CWT
    Extracting a Weak Binary QPSK Signal from 80 dB of Noise Using Time-Dependant Thresholding
    Noise Identification Using the CWT and the DWT
    Compression of Images Using a 2-D DWT with the Biorthogonal Wavelet
    JPEG Compression Using Wavelets
    Example showing Superior Denoising Capability Using the UDWT
    Summary
  • CHAPTER 13 - Building the Scaling Function (phi) using the PRQMF Filters and the Dilation Equation
    Review of Building Wavelet Function (Estimation) Using Wavelet Filter Points at Known Locations to Produce Additional Points
    Building Scaling Function (Estimation) Using Scaling Function Filter Points at Known Locations
    Repeated Upsampling and Filtering to Produce Multi-Point Estimation of a “Continuous” Scaling Function
    Overlaying Original Scaling Function Filter Points on the “Continuous” Scaling Function Estimation for Perfect Fit
    Historical Perspective of Roman Numerals, Negative and Irrational Numbers, Imaginary Numbers, etc.
    The 2-Scale Difference Equation and the Scaling Function Dilation Equation
    Relating the Scaling Function Dilation Equation to the Conventional Discrete Wavelet Transform
    Recursive Wavelet Processing as a “Child of the Digital Age”
    Summary
  • CHAPTER 14 - Building the Scaling Function (phi) using the Perfect Reconstruction Quadrature Mirror Filters and Simple Convolution
    Replication of the Dilation Equation by Dyadic Upsampling and Convolution
    The Scaling Function is Built from the Filters, not the Other Way Around
    Upsampling and Filtering can be Observed in DWT Signal Flow Charts—Miniature Scaling Function Replicas Seen as a Result
    Summary
  • CHAPTER 15 - Building the Wavelet Function (psi) from Both the Dilation Equation and by Simple Convolution
    Wavelet Function Dilation Equation uses BOTH Scaling Function AND Wavelet Function Basic Filter Points (LowPass and HighPass) to Produce Additional Points
    Other Similarities and Differences to the Scaling Function Dilation Equation
    Another Look at Repeated Upsampling and Filtering to Build the Multi-Point “Continuous” Wavelet Estimation
    Upsampling and Filtering can be Observed in DWT Signal Flow Charts
    Miniature Wavelet (Function) Replicas Also Observed as Artifacts from Repeated Upsampling and Filtering in Signal Diagrams.
    Summary
  • CHAPTER 16 - Perfect Reconstruction Begins with the HalfBand Filters
    A First Look at the HalfBand (HB) Filters
    HighPass HB Filter Factored into Wavelet Decomposition and Reconstruction Filters
    LowPass HB Filter Factored into Scaling Function Decomposition and Reconstruction Filters
    HB Filters in the Simple Undecimated Discrete Wavelet Transform
    HB Filters in the Conventional (Downsampled) Discrete Wavelet Transform
    Summary
  • CHAPTER 17 - Alias Cancellation Demonstrated in the Time Domain
    Step-By-Step Look at Convolution (Filtering) on both the HP and LP Paths of a DWT
    Cancellation of HP and LP Terms Except When They Align
    Perfect Reconstruction to Within a Delay and a Constant of Multiplication
    Linear Time Invariant (LTI) Properties of the DWT
    Signal Flow Diagrams of the LTI DWT to Extract Needed Approximations and Details
    Summary
  • CHAPTER 18 - Alias Cancellation Demonstrated in the Frequency Domain
    Filtering of the Signal in the DWT by the Decomposition Filters
    Downsampling the Result Which Can Cause Aliasing
    Equivalence of Downsampling to “Sliding” Higher Frequencies to the Left
    Upsampling Now Causes Imaging or “Unfolding” of Frequencies
    Complex Addition of HP and LP Paths
    Alias Cancellation on Because Same Magnitude but Opposite Phase from the HP and LP Paths
    Signal Reconstruction Because In Phase Components from the HP and LP Paths
    Summary
  • CHAPTER 19 - Relating Alias Cancellation Concepts to Equations Found in Traditional Literature
    Paraunitary Conditions
    “No-Distortion” Equations and In-Phase Addition
    Alias Cancellation Equations and Out-Of-Phase Cancellations
    Summary
  • CHAPTER 20 - Creating “Fake” Wavelets
    Appreciating the Elegant Properties of the Classic Wavelets
    Single Cycle of a Sine Wave as a “Crude” Fake Wavelet
    CWT Display Comparison Using Haar and Db4 Wavelets
    Using a GPS Signal as a “Fake Wavelet” in a CWT to Account for Doppler, Slew, and Chirp
    Truncated Db4 Wavelet Filters—Valid HalfBand Filters but Fewer Vanishing Moments
    Vanishing Moments Revisited
    Summary
  • CHAPTER 21 - Deriving the “Magic Numbers” of the Wavelet Filters from the Desired Capabilities
    Vanishing Moments Properties
    Desired Orthogonality Properties
    Wavelet Filter Values Sum to Zero
    Squares of Wavelet Filter Values Sum to Unity (Unit Energy)
    Simple Substitution to Produce the “Magic Numbers” for all Four Basic Wavelet Filters
    Summary
  • CHAPTER 22 - Trading Pure Orthogonality for “Biorthogonality”, Symmetry, and Linear Phase
    Another Way to Factor the HalfBand Filters
    Decomposition and Reconstruction Filters with Different Lengths
    Symmetry and Linear Phase
    Comparing Db4 Filters (4 Points Each) with BIOR 3/5 Filters (3 or 5 Points Each)
    Limited Orthogonality or “Bi”-Orthogonality
    Use of the BIOR 7/9 Filters for JPEG and FBI Fingerprint Compression
    Summary
  • CHAPTER 23 - The Undecimated Discrete Wavelet Transform (UDWT) Revisited
    Extra Storage and Computational Burden vs. Alias-Free Processing
    Stretching the Filters Correctly in Octaves of Frequency
    Comparison of UDWT and Conventional DWT Displays
    Pathological Noise Cases Which Favor the use of the UDWT
    The UDWT as Sanity Check for the DWT
    Hybrid Methods using Both UDWT and DWT
    Summary
  • APPENDICES


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