To improve the quality of point cloud data, as well as maintain edge and detail information in the course of filtering intensity data, a three-dimensional (3D) diffusion filtering equation based on the general principle of diffusion filtering is established in this paper. Moreover, we derive theoretical formulas for the scale parameter and maximum iteration number and achieve self-adaptive denoising, fine control of the point cloud filtering, and accurate prediction of the diffusion convergence. Through experiments with three types of typical point cloud intensity data, the theoretical formulas for the scale parameter and iteration number are verified. Comparative experiments with point cloud data of different types show that the 3D diffusion filtering method has significant denoising and edge-preserving abilities. Compared with the traditional median filtering algorithm, the signal-to-noise ratio (SNR) of the point cloud after filtering is increased by an average of 10% and above, with a maximum value of 40% and above.

References

References
1.
Li
,
Z.
,
Li
,
Q.
, and
Wang
,
Q.
,
2004
, “
Noise Characteristic in Active Laser Imaging System by Statistic Analysis
,”
Chin. J. Lasers
,
31
(
9
), pp.
1081
1085
.
2.
Chen
,
Y.
,
Shen
,
Y.
,
Jianbing
,
J. I.
, and
Guojun
,
L. I.
,
2003
, “
A New Fast Weighted Median Filtering Algorithm
,”
Comput. Eng.
,
29
(
3
), pp.
89
90
.
3.
Li
,
X.
,
Jiang
,
D.
, and
Wang
,
Z.
,
2012
, “
Weighted Median Filtering of Im Based on Grads Similarity
,”
J. Univ. Electron. Sci. Technol. China
,
41
(
1
), pp.
114
119
.
4.
Feng
,
X. K.
,
Xiao
,
X. M.
, and
Yin
,
H. J.
,
2000
, “
The Directional Medial Filtering With Weights
,”
J. Image Graphics
,
5A
(
7
), pp.
609
611
.
5.
Czerwinski
,
R. N.
,
Jones
,
D. L.
, and
O'Brien
,
W. D.
,
1995
, “
Ultrasound Speckle Reduction by Directional Median Filtering
,”
International Conference on Image Processing
, Vol.
1
, pp.
358
358
.
6.
Shu Tao
,
L. I.
, and
Wang
,
Y. N.
,
2000
, “
Non-Linear Adaptive Removal of Salt and Pepper Noise From Images
,”
J. Image Graphics
,
5A
(
12
), pp.
999
1001
.
7.
Zhao
,
C. H.
,
Hui
,
J. Y.
,
Wang
,
W.
, and
Sun
,
S. H.
,
2000
, “
A Class of Adaptive Ranked-Order Morphological Filters
,”
J. Image Graphics
,
5A
(
8
), pp.
674
677
.
8.
Ma
,
J.
,
Yan
,
J. B.
,
Liu
,
G. Z.
, and
Liu
,
J. X.
,
2010
, “
Anisotropic Diffusion Smoothing of Mixed Noise
,”
J. Cent. South Univ.
,
41
(
1
), pp.
231
237
.
9.
Bai
,
J.
, and
Feng
,
X. C.
,
2007
, “
Fractional-Order Anisotropic Diffusion for Image Denoising
,”
IEEE Trans. Image Process.
,
16
(
10
), pp.
2492
2502
.
10.
Chen
,
S.
, and
Yang
,
X.
,
2006
, “
A New Adaptive Diffusion Equation for Image Noise Removal and Feature Preservation
,”
International Conference on Pattern Recognition
, Vol.
3
, pp.
885
888
.
11.
Zhang
,
C.
,
Zhao
,
Y.
, and
Lian
,
Y.
,
2012
, “
Research on Anisotropic Diffusion Denoising Development
,”
Electron. Opt. Control
,
19
(
5
), pp.
51
55
.
12.
Qian
,
S.
,
Zhu
,
J.
,
Zhiwei
,
L. I.
,
Yin
,
H.
, and
Bo
,
H. U.
,
2009
, “
A New Adaptive InSAR Interferogram Filter Based on SNR
,”
Acta Geod. Cartographica Sin.
,
38
(
5
), pp.
437
442
.
13.
Yang
,
S. B.
,
Bing Bai
,
L. I.
,
Shen
,
S. H.
, and
Zhang
,
P. P.
,
2006
, “
Structure Retaining Linear Multi-Channel SAR Image Speckle Filter
,”
Acta Geod. Cartographica Sin.
,
35
(
4
), pp.
364
370
.
14.
Jiang
,
L.
,
Zhao
,
C.
, and
Wang
,
Q.
,
2003
, “
Algorithm About Suppressing Speckle Noise in Coherent Laser Radar Imagery
,”
Acta Opt. Sin.
,
23
(
5
), pp.
541
546
.
15.
Jiang
,
L.
, and
Zhao
,
C.
,
2003
, “
Speckle Noise Suppressing Based on Multilevel Nonlinear Weighted Mean Median Filter
,”
Laser Infrared
,
33
(
5
), pp.
380
382
.
16.
Li
,
Z. Q.
,
Wang
,
Q.
, and
Qi
,
L. I.
,
2003
, “
Comparison of Algorithms for Suppressing Speckle in Laser Imaging System
,”
Infrared Laser Eng.
,
32
(
4
), pp.
130
133
.
17.
Lai
,
X. D.
, and
Wan
,
Y. C.
,
2005
, “
A Kind of Filtering Algorithms for Lidar Intensity Image Based on Flatness Terrain
,”
Chin. J. Lasers
,
32
(
10
), pp.
1325
1329
.
18.
Nobrega
,
R. A. A.
,
Quintanilha
,
J. A.
, and
O'Hara
,
C. G.
,
2007
, “
A Noise-Removal Approach for Lidar Intensity Images Using Anisotropic Diffusion Filtering to Preserve Object Shape Characteristics
,”
ASPRS
Annual Conference
, Tampa, FL, May 7–11.
19.
Perona
,
P.
, and
Malik
,
J.
,
1990
, “
Scale-Space and Edge Detection Using Anisotropic Diffusion
,”
IEEE Trans. Pattern Anal. Mach. Intell.
,
12
(
7
), pp.
629
639
.
20.
Zou
,
M.
,
2004
,
Deconvolution and Signal Recovery
,
National Defence Industry Press
,
Beijing, China
, pp.
186
188
.
21.
Wang
,
X.
,
Wang
,
C.
, and
Zhang
,
Y.
,
2010
, “
Research on SNR of Point Target Image
,”
Electron. Opt. Control
,
17
(
1
), pp.
18
21
.
You do not currently have access to this content.