A completed modeling of local binary pattern operator
1. A Completed Modeling of Local Binary
Pattern Operator for Texture Classification
Zhenhua Guo,
Lei Zhang,
David Zhang
2012 IEEE Transactions on Image Processing
NTNU-CSIE Chen-Lin Yu , Total page:23
4. Texture Classification
Texture classification is an active research topic in
computer vision and pattern recognition.
In texture classification, the goal is to assign an
unknown sample image to one of a set of known texture
classes.
Texture classification process involves two phases:
(1) learning phase and (2) the recognition phase
4
5. Divided texture analysis methods into
four categories:
Statistical
Geometrical
Model-based
Signal processing
http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/OJALA1/texclas.htm
6. Goal:
Proposing a new local feature extractor to generalize
and complete LBP(CLBP).
Some information is missed in LBP code. We
attempts to address that how to effectively represent
the missing information in the LBP so that better
texture classification.
In CLBP, a local region is represented by its center
pixel and a local difference sign-magnitude transform
(LDSMT).
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9. Rotation variance
We define formula U which value of an LBP pattern
is defined as the number of spatial transitions
(bitwise 0/1 changes) in that pattern.
0
1
1
0
1
0
0
0
01110000
U(LBPP,R) = 2
1
1
1
1
1
0
0
1
11110101
U(LBPP,R) = 4
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10. The uniform LBP patterns refer to the patterns
which have limited transition or discontinuities
(U<=2) in the circular binary presentation [13].
(superscript “riu2” means rotation invariant “uniform”
patterns with U<=2)
[13] Multiresolution gray-scale and rotation invariant texture classification with Local Binary Pattern
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13. I. Local Difference Sign-Magnitude
Transform (LDSMT)
a 3*3 sample block
sign components
local differences
magnitude components
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14. Fig(b) local differences vector
Fig(c) sign vector
Fig(d) magnitude vector
Ex: different vector is [3,9,-13,-16,-15,74,39,31]
after LDMST sign vector is [1,1,-1,-1,-1,1,1,1]
and magnitude vector is [3,9,13,16,15,74,39,31]
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15. II. CLBP Map
By the LDSMT ,three operators, namely CLBP_C,
CLBP_S and CLBP_M, are proposed to code the C,
S and M features, respectively
Combine CLBP_S and CLBP_M
• 1. Concatenation (CLBP_S_M)
• 2. Joint (CLBP_S/M)
Combine three operators
• 1. Joint (CLBP_S/M/C)
• 2. Hybrid (CLBP_M_S/C or CLBP_S_M/C)
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16. Dissimilarity Metric and Multi-scale CLBP
There are various metrics to evaluate between two
histograms, such as histogram intersection, loglikelihood ratio, and chi-square statistic [13].
The nearest neighborhood classifier with the chisquare distance is used to measure the dissimilarity
between two histograms
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18. Outex Database
Includes 24 classes of textures , each texture available at the
site is captured using three different simulated illuminants provided in the light source:
– H : 2300K (陽光 左下)
– Inca : 2856K (日光燈 右下)
– TL84 : 4000K(螢光燈 右上)
and nine rotation angles
(0o,5º,10º,15º,30º,45º,60º,75º and 90º)
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21. We analyzed LBP from a viewpoint of local
difference sign-magnitude transform (LDSMT), and
consequently a new scheme, namely completed
LBP (CLBP)
By fusing CLBP_C、CLBP_S、CLBP_M codes, it
will much better texture classification accuracy than
the state-of-the-arts LBP.
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