下載/瀏覽Download
Download
Report
Transcript 下載/瀏覽Download
Improvement of Zernike Moment Descriptors
on Affine Transformed Shapes
Adviser: 李育強
Speaker: 楊智雁
Date:2010/01/18
Signal Processing and Its Applications, 2007. ISSPA 2007. 9th International
Symposium on
南台科技大學
資訊工程系
Outline
2
1
Introduction
2
Proposed Algorithm
3
Experimental Results
4
Conclusion
1.Introduction
Skew and stretch distortions are common among
shapes obtained from natural objects
Zhang and Lu proposed a method which involves
rotation and scale normalization
We propose a new method for extracting Zernike
moments addressing this issue
3
2. Proposed Algorithm
Three second order geometric moments for a
region
( )
2
f ( , y)
y ( )( y y) f ( x, y)
y
yy ( y y) 2 f ( , y )
y
4
2. Proposed Algorithm (c.)
R {( , y) | d 2exy f y 1}
2
5
2
2
2
2. Proposed Algorithm (c.)
1
x
a
'
y
0
'
1
x' ' d max
y ' '
0
6
0 cos
1
sin
b
0
x'
1 y '
d man
sin x x
cos
y y
3. Experimental Results
1.Rotation and scale as Linear invariance properties
2.Stretching and skew as Non-linear invariance
properties
7
3. Experimental Results (c.)
We evaluate linear invariance properties, by
comparing the performance of the proposed
method to Bin’s reported work
r
8
Z Z
Z
'
3. Experimental Results (c.)
9
3. Experimental Results (c.)
10
3. Experimental Results (c.)
11
4. Conclusion
We proposed a new method to improve the
stretch and skew invariance properties of
Zernike moments
Retains the rotation and scale invariance
properties as well
12
南台科技大學
資訊工程系