Improving Laplacian Pyramid Coding - PowerPoint PPT Presentation

1 / 14
About This Presentation
Title:

Improving Laplacian Pyramid Coding

Description:

'Lena', 512x512, 8 bpp. Optimal Decoder for Noise Reduction. S. Zakhary, D. Chen, EE 398A ... 'Lena', 512x512, 8 bpp. Rate Allocation for Levels of the LP ... – PowerPoint PPT presentation

Number of Views:64
Avg rating:3.0/5.0
Slides: 15
Provided by: stan7
Category:

less

Transcript and Presenter's Notes

Title: Improving Laplacian Pyramid Coding


1
Improving Laplacian Pyramid Coding
  • Sameh Zakhary, David Chen
  • Stanford University
  • EE 398A Final Project

2
Outline
  • Laplacian pyramid (LP) encoder and decoder
  • LP with quantization noise
  • Optimal decoder for noise reduction
  • Rate allocation for levels of the LP
  • Extensions of the LP structure
  • Noise processing at the encoder
  • Closed-loop encoder
  • Lifted pyramid
  • SVD-based transform
  • Pseudo-wavelet encoder with SPIHT

3
LP Encoder and Decoder
encoder
(Burt, Adelson, 1983)
decoder
4
LP with Quantization Noise
encoder
decoder
5
Optimal Decoder for Noise Reduction
  • Analysis matrix has more rows than columns
  • Infinitely many synthesis matrices

1.5N

N
(Do, Vetterli, 2003)
(Burt, Adelson, 1983)
6
Optimal Decoder for Noise Reduction
Lena, 512x512, 8 bpp
7
Optimal Decoder for Noise Reduction
Lena, 512x512, 8 bpp
8
Rate Allocation for Levels of the LP
  • General Lagrangian minimization problem
  • High-rate solution

(JPEG 2000, Ch. 5)
9
Noise Processing at the Encoder
10
Noise Processing at the Encoder
Lena, 512x512, 8 bpp, 9/7 filters
11
Extensions of the LP Structure
  • Closed-loop encoder
  • Uses feedback idea from predictive coding
  • 1 db improvement over open-loop at high rates
  • (Ramchandran, 1994)
  • Lifted pyramid
  • Minimizes aliasing for video applications
  • (Flierl, Vanderghyenst, 2005)
  • SVD-based transform
  • Critical representation of the LP
  • (Rath, Guillemot, 2006)

12
Pseudo-Wavelet Decomposition
9/7 wavelet
insert coarse
SPIHT Encoder
bitstream
13
Pseudo-Wavelet Decomposition
Lena, 512x512, 8 bpp, 9/7 filters
14
Summary of Project Results
  • Compared performances of simple and optimal LP
    decoders
  • Constructed practical rate allocation algorithm
    for multiple levels of LP
  • Researched extensions of the basic LP structure
  • Noise processing at the encoder
  • Closed-loop encoder
  • Lifted pyramid
  • SVD-based transform
  • Pseudo-wavelet encoder with SPIHT
Write a Comment
User Comments (0)
About PowerShow.com