bul 2004
——
e object
ject and
ructure.,
undancy
pectrum
Landsat
imaging
age
41
46
31
1€ same
pectrum
nd these
he band
in this
ression.
different
s design
, the 2D
textured
are high
elet can
ly. This
in high
wavelet
alyse to
wavelet
efers to
[lowing
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
® Consistent monotony
MS Mon
@ Gradually perfectibility
n-0.UV,-LG o
mez
I^ Cru. (1)
Q Regulation of flex
fo)eyp,e/fQxep vmezo
Riesze there is
Ve
@ Existency of base:
pel’,
And ge V.
eX x-n),neZz as theRiesze base of
can meet the following condition:
V,^spanie(x-n)nez (9
< < < ©
Á A; which can obtain the
(CHE
Thus, there is
following arbitrary relation to
AX|ci | X con) s c4
neZ nez”
T
(5)
where presents the square summary of total list, that is:
[ou (ar). 2 al 2m (6)
(2) Construction of Multi-band wavelet
As the multi-scale analyse, the scale function with interposition
property can be constructed and corresponding conjugated
filtering of M-band as the following equation:
5
M
[=z [+6
+
M 4-7) 2 2
H(z)=
(7)
Thus, the wavelet coefficient can be obtained through the above
equation.
(3) Image multi-band decompose and reconstruct
As the above scale function and the , we can obtain the image
wavelet decomposition and reconstruction algorithm.
; a T
Taken image as ^ ^2 ^. the wavelet decomposition formula
of M-band wavelet can be expressed as following:
HJ = NS _MkCn, —MI uA M (8)
My M,
57
=0,/<s, <M—!
22 Cd Mk n, S ut nm 5
Ye. Mk n, — E uin 3 ys
Ye. Mk CA ny —A m jun, uS
The corresponding image reconstruct to the M-band wavelet
can be expressed as:
p Se Ci-Mn, aur
mn Ma
SS C on Ci-un, T +
Jh Hy
bh +
z0/ss,sM-lI
M-1
>, Nw. Mn, dr. Mn, D.
s,.$2=0,5,+s2=0 | M
M-l
NE 3,555 )
dq Mn, LÆ k-Mn, D.
Sp S2 m0, s ess m
(10)
2.3 Edge Reservation based Quantification Algorithm in
Multi-band Wavelet Domain
After multi-band wavelet transformation, the images are
divided into different parts. The compression based on wavelet
generally adopt different quantification methods to different
wavelet coefficient. The 2D wavelet transformation can obtain
the edge image while the edge image size is one of 2* of the
original image size. The multi-band wavelet can obtain edge
image with arbitrary size and can well keep the image structure
and edge feature. Figure 1 is the low frequency edge coefficient
images of 3D wavelet decomposition.
Figure 1 3D Wavelet Decomposition
The general quantification of the high frequency wavelet
coefficient is the same. As figure shown, the high frequency
coefficient of multispectrum image after wavelet transformation
preserves the texture structure and edge feature in different
directions. If the coefficient present the edge, the wavelet
coefficient is high. And the plain region in the image has low
wavelet coefficient. In order to keep the object edge and
contour, the quantification of wavelet coefficient with edge and
contour should adopt high and precise level while the plain
region can be quantize with coarse level. In this paper, the
wavelet coefficient quantification is done after the edge
extraction. Hence the edge is detected from the high frequency
wavelet coefficient, the left wavelet coefficient can be
;50/ 5 $M-l ©,