4492 IEEE TRANSACTIONS ON IMAGE PROCESSING, VOL. 21, NO. 10, OCTOBER 2012
Correspondence
Completed Local Binary Count for Rotation Invariant
Texture Classification
Yang Zhao, De-Shuang Huang, Senior Member, IEEE,
and Wei Jia, Member, IEEE
Abstract—In this brief, a novel local descriptor, named local
binary count (LBC), is proposed for rotation invariant texture
classification. The proposed LBC can extract the local binary
grayscale difference information, and totally abandon the local
binary structural information. Although the LBC codes do not
represent visual microstructure, the statistics of LBC features can
represent the local texture effectively. In addition, a completed
LBC (CLBC) is also proposed to enhance the performance of
texture classification. Experimental results obtained from three
databases demonstrate that the proposed CLBC can achieve
comparable accurate classification rates with completed local
binary pattern.
Index Terms— Local binary pattern (LBP), local binary count
(LBC), rotation invariance, texture classification.
I. INTRODUCTION
Texture classification is very useful in many applications, such as
remote sensing, biomedical image analysis, image recognition and
retrieval. Thus, it is an important issue in image processing and
computer vision. Generally, texture images captured in the real world
may have obvious orientation variations. Rotation invariant texture
analysis is therefore immensely needed from both the practical and
theoretical viewpoints.
So far, many approaches have been proposed to achieve rotation
invariance for texture classification which can be broadly divided into
two categories, i.e., statistical methods and model based methods,
respectively. In statistical methods, texture is generally described by
the statistics of selected features, e.g., invariant histogram, texture
elements, and micro-structures. Davis et al [1] exploited polarograms
and generalized co-occurrence matrices to obtain rotation invariant
statistical features. Duvernoy et al [2] proposed Fourier descriptors
to extract the rotation invariant texture feature on the spectrum
domain. Goyal et al [3] proposed a method by using texel property
histogram. Eichmann et al [4] presented texture descriptors based
on line structures extracted by Hough transform. In model based
methods, texture is usually presented as a probability model or as
Manuscript received October 17, 2011; revised May 2, 2012; accepted
May 20, 2012. Date of publication June 12, 2012; date of current
version September 13, 2012. This work was supported by the National
Science Foundation of China, under Grant 61133010, Grant 31071168, Grant
61005010, Grant 60905023, and Grant 60975005, and the China Post-
Doctoral Science Foundation under Grant 20100480708. The associate editor
coordinating the review of this manuscript and approving it for publication was
Prof. Zhou Wang.
Y. Zhao is with the Department of Automation, University of Science and
Technology of China, Hefei 230027, China, and also with the Hefei Institute
of Intelligent Machines, Chinese Academy of Science, Hefei 230031, China
(e-mail: zyknight@mail.ustc.edu.cn).
D.-S. Huang is with the School of Electronics and Information Engineering,
Tongji University, Shanghai 201804, China (e-mail: dshuang@tongji.edu.cn).
W. Jia is with the Hefei Institute of Intelligent Machines, Chinese Academy
of Science, Hefei 230031, China (e-mail: icg.jiawei@gmail.com).
Digital Object Identifier 10.1109/TIP.2012.2204271
a linear combination of a set of basis functions. Kashyap et al [5]
developed a circular simultaneous autoregressive (CSAR) model for
rotation invariant texture classification. Cohen et al [6] characterized
texture as Gaussian Markov random fields and used the maximum
likelihood to estimate rotation angles. Chen and Kundu [7] addressed
rotation invariant by using multichannel sub-bands decomposition and
hidden Markov model (HMM). Porter et al [8] exploited the wavelet
transform for rotation invariant texture classification by using the
Daubechies four-tap wavelet filter coefficients.
Although these aforementioned methods are proven to be rotation
invariant, they are not very robust to variances of illumination. In [9],
Ojala et al proposed an efficient method, namely Local Binary Pattern
(LBP), for rotation invariant texture classification. As shown in Fig. 1,
the algorithm of LBP contains two main steps, i.e., thresholding step
and encoding step. In the thresholding step, the values of neighbor
pixels are turned to binary values (0 or 1) by comparing them with
the central pixel. Obviously, the local binary grayscale difference
information is extracted in the thresholding step. In the encoding step,
the binary numbers are encoded to characterize a structural pattern,
and then the code is transformed into decimal number. Aiming
at achieving rotation invariance, Ojala proposed rotation invariant
uniform LBP (LBP
riu2
), in which only rotation invariant uniform
local binary patterns were selected. It was believed that LBP is an
excellent measure of the spatial structure of local image texture since
it can effectively detect micro-structures (e.g., edges, lines, spots)
information.
Since Ojala’s work [9], a lot of variants of the LBP for rotation
invariant texture classification have been proposed, some of which
were focused on how to extract more discriminative patterns.
For example, Heikkila et al [10] proposed center-symmetric
LBP (CS-LBP) by comparing center-symmetric pairs of pixels
instead of comparing neighbors with central pixels. Liao et al [11]
presented Dominant LBP (DLBP), in which dominant patterns were
experimentally chosen from all rotation invariant patterns. Others
tried to further explore the contrast information. For example, Tan
and Triggs [12] proposed the method of Local Ternary Pattern
(LTP), which extends original LBP to 3-valued codes. Recently,
Guo et al [13] proposed the completed LBP (CLBP) by combining
the conventional LBP with the measures of local intensity difference
and central gray level. Khellah [14] presented a new method for
texture classification, which combines Dominant Neighborhood
Structure (DNS) and traditional LBP. It should be noticed that the
LBP encoding process is used in all of these variants mentioned
above because it is believed that structural patterns characterized by
the binary codes are more important for rotation invariant texture
recognition while local binary grayscale difference information is
considered to be merely a supplement of micro-structures. Recently,
there is also another way to look at LBP, e.g., LBP is regarded as
a special filter-based textureo
¯
perator [19], [20].
Then, is micro-structure information really the main role in LBP
for rotation invariant texture recognition? It seems that nobody has
investigated this problem in depth so far. In this paper, we shall try to
address this question by proposing a new local operator that discards
the structural information from LBP operator, which is named as
Local Binary Count (LBC). Experimental results illustrate that the
most discriminative information of local texture for rotation invariant
texture classification is not the ‘micro-structures’ information but
the local binary grayscale difference information. Motivated by the
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