1. IMAGE DATA COMPRESSION IN WAVELET TRANSFORM DOMAIN USING MODIFIED LBG ALGORITHM
Source: ACM International Conference Proceding
of the 1st International Symposium on
Information and Communication
Tech:pp.88-93, 2003.
Author: Othman Omran Khalifa
Reporter: Jain Yaun Chang
Date：2005/5/3

2. Outline The Discrete Wavelet Transform
Modified LBG Algorithm Using Partial Search Partial Distortion
Simulation Results
Conclusions

3. The Discrete Wavelet Transform
第一次水平分割示意圖

4. The Discrete Wavelet Transform (cont.)
第一次垂直分割示意圖

5. The Discrete Wavelet Transform (cont.)
三階 Haar 離散小波轉換

6. The Discrete Wavelet Transform (cont.)

7. Modified LBG Algorithm Using Partial Search Partial Distortion
Step (1). Initialization.
n =Number of training vectors
N =Codebook size
k =Vector dimension
C0 =Initial codebook
D-1 =Initial average distortion

8. Modified LBG Algorithm Using Partial Search Partial Distortion (cont.)
Step (2).
=> m1= σ2= h=0.11
=> m2= σ2= h=0.83
=> m3= σ2= h=0.07
=> m4= σ2= h=0.74
=> m5= σ2= h=2.77
=> m6= σ2= h=1.09
=> m7= σ2= h=0.86
=> m8= σ2= h=0.5

9. Modified LBG Algorithm Using Partial Search Partial Distortion (cont.)
cw1’
(191, 198, 190, 188)
cw2’
(184, 192, 193, 197)
cw3’
(151, 153, 169, 171)
cw4’
(77, 83, 84, 65)
cw5’
(34, 50, 43, 47)
cw6’
(210, 213, 192, 230)
cw7’
(23, 29, 16, 19)
cw8’
(63, 70, 94, 98)

10. Modified LBG Algorithm Using Partial Search Partial Distortion (cont.)
Step (3). Calculate the minimum distortion partition.
(a). Compute h for the input vector x
v = (150,145,121,130)
=>m= σ2= h=0.98

11. Modified LBG Algorithm Using Partial Search Partial Distortion (cont.)
(b). Find the best match of h from the
sorted codebook
cw7’ (23, 29, 16, 19)

12. Modified LBG Algorithm Using Partial Search Partial Distortion
(c). Define the partial codebook, window
size + - T from the best match vector.
Ex: T=1
cw6’
(210, 213, 192, 230)
cw7’
(23, 29, 16, 19)
cw8’
(63, 70, 94, 98)

13. Modified LBG Algorithm Using Partial Search Partial Distortion
(d). calculating the distortion of each
codevector by select the minimum
distortion.
d(v, cw6’) = 152.5
d(v, cw7’) = 235.
d(v, cw8’) = 122.3
So, we choose cw8’ to replace the input vector v

14. Modified LBG Algorithm Using Partial Search Partial Distortion (cont.)
Step (4).

15. Modified LBG Algorithm Using Partial Search Partial Distortion (cont.)
Step (5).
If (Diteration-1 – Diteration) / Diteration <=δ
stop with codebook

16. Simulation Results

17. Simulation Results (cont.)

18. Simulation Results (cont.)

19. Conclusions
the proposed wavelet code performed well when compared with the industrial standard JPEG algorithm and much better than vector quantisation technique.
These results show that the algorithm provides a highly competitive solution to the problem of image data compression.