(a) (b)
(d) (e) (0
Figure 6. Textures of SAR imagery with different
orientations(a to f stand the texture images of g = 7, 4 to g2z
with every 7
ry 7 )
This paper will establish the transformation of horizontal
texture (0 = ) since the two types of images have more
explicit horizontal and vertical texture.
Since the amount of calculation of the algorithm proposed by
Kain is very great, this paper will take the following two steps
to reduce the amount of calculation. On the one hand, it will use
a local horizontal texture (9 - 7) of figure4 and figure6 with
50 X 50 instead of the whole texture image. On the other hand,
it will use the K-means algorithm before establishing the texture
mapping.
The registered local texture of QuickBird imagery and SAR
imagery used in this experiment are shown in figure7 and
figure8
» ud à "
Figure 7. QuickBird imagery Figure 8. SAR imagery
figure9 shows the outputs of transformation with different m
which is the number of single Gaussians in one GMM.
Spatially, the output of transformation has a high similarity and
expression with the SAR imagery in figure8, such as the
building at the top of left corner both in figure7 and figure8. Its
shape and scale have transformed to be more similar to the SAR
imagery. Consequently, it demonstrates that the GMM can play
a good performance in the transformational of texture features
description under different imaging conditions.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
a
(c) (d)
Figure 9. The transformation results with different m
(a, result with m4; b, result with m-8; c, result with m=16;
d,result with m=64)
Table! shows the results of the average of transformation error
precision with different m in the experiment according to
Eq.(19). And it demonstrated that the transformation error
precision will reduce by the number of single Gaussian
increasing.
m-4 m-8 m=16 m=64
Average error | 0.2602 0.2533 0.2493 0.2482
precision
Table 1. Average error precision
Figurel0 shows the comparison of QuickBird imagery, SAR
imagery and the transformed result with m=64. The X-axis 1s
the point number from 1 to 50 and y-axis is the value of each
pixel. There are three types of lines in Figurel0. The solid line
with point represents the value of SAR imagery texture. The
solid line with star stands the value of transformed texture and
dotted line stands the value of Quickbird imagery texture.
The Sua eh Vey bed a GI
EGG ud Eo s RTE RBANLG WEEE ERR
FRE RTE RRR NY
Figure 10. The comparison of results