MEDICAL IMAGE SEGMENTATION FOR DISEASE DETECTION USING DIGITAL FILTER

International Journal of Technical Research and Applications e-ISSN: 2320-8163,
www.ijtra.com Volume 2, Issue 4 (July-Aug 2014), PP. 193-196
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MEDICAL IMAGE SEGMENTATION FOR
DISEASE DETECTION USING DIGITAL FILTER
ANURAG OKSIYA
Department of Electronics Engineering, PG Student,
KITS Ramtek, Nagpur, India.
oanurag99@gmail.com
ABSTRACT- Tonsillitis is a disease that can be found in every
part of the world. Moreover, it is one of the main causes
intervening for heart attack and pneumonia. It has been reported
that there are a large number of people having died because of
heart attack and pneumonia. To improve data transfer rates, this
paper proposes Gabor filter design with efficient noise reduction
and less power consumption usage is proposed in this paper.
Using textural properties of anatomical structures the filter
design is suitable for detecting the early stages of disease. The
code for Gabor filter will be developed in MATLAB.
Keywords- Medical image, MAT LAB
I. INTRODUCTION
Image segmentation is the process of partitioning a digital
image into multiple segments i.e. sets of pixels. Segmentation
of images by using textural property of anatomical structures
and regions of interest has a crucial role in most medical
imaging applications. The segmented image is more
meaningful and easier to analyze.
For medical images, Color image segmentation and cell
counting system is preferred because the gray levels alone
may not be sufficient to perform accurate medical image
segmentation, as many soft tissues have overlapping gray level
ranges. Thus the use of the textural properties of the
anatomical structures could be useful. For this purpose a
customized 2D Gabor Filter for RGB color image
segmentation will be designed. It has proved to be an effective
segmentation tool with improved data transfer rate, efficient
noise reduction, less power consumption and reduced memory
usage .Gabor function locates the texture features in the spatial
domain. Gabor filters have proved to be an effective
Segmentation tool because of two major factors as: Their
capability to achieve optimal uncertainty in both space and
frequency, and their similarity with primary visual cortex of
mammals
We focus on detecting main features of disease and create
a resulting image showing affected Area on MATLAB. The
Gabor Filter for color image segmentation will be coded using
VHDL in Modelsim and will be implemented in SPARTAN-
3E FPGA. Field Programmable Gate Array (FPGA)
technology has become a viable target for the implementation
of algorithms Suited to image processing applications. Finally
the segmented image will be observed on MATLAB.
II. DESIGN METHODOLOGY
The design approach will be divided in six modules as
described below
Fig.1 Block Diagram of proposed plane
A. MATLAB IMAGE READING MODULE
This is a simple image reading and resizing module
written in MATLAB. It reads two images from database for
comparison. One of which is healthy image (figure (2)) and
another having disease features (figure (3)). The comparison
will generate a test input file which we can use as input to
VHDL module.
Fig.2 Healthy tonsils Fig.3 Disease affected tonsils
B. GABOR ALGORITHM
Our Gabor-type filter designed with Gabor algorithm is
used as the processing unit in a disease detection module.
Gabor Filters have received considerable attention because the
characteristics of certain cells in the visual cortex of some
mammals can be approximated by these filters. Gabor filters
are a large set of linear filters, having the impulse response
defined as a harmonic function multiplied by a Gaussian
function with various orientations. It can be viewed as a
sinusoidal plane of particular frequency and orientation,
modulated by a Gaussian envelope. The space domain
representation of the complex 2D Gabor filters (or functions)
is given by
Where s(x, y) is a complex sinusoid, known as a
carrier and g(x, y) is a 2-D Gaussian shaped function, known

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as envelope and it’s spatial extent is given by the
parameter . These are defined as follows,
Thus the 2-D Gabor filter equation can be written as:
---- (1)
The equivalent frequency representation of Gabor filters is:
---- (2)
The Gabor filter is essentially a bandpass filter
centered at (U, V) in the frequency domain, with bandwidth
determined by sigmag. Its radial center frequency measured in
cycles/ image, fc = rootU2+V2, is oriented (in radians) from
the u-axis with Q = tan−1 (V/U). We assume, for the
simplicity, that the Gaussian g(x, y) is a symmetrical function.
The Gabor filter bank is obtained by generating Gabor filters
for all directions from 0 to 360 and varying the frequency with
the fc factor. The representation of the generated filters in the
frequency domain is shown in Figure (4).
Fig.4The frequency domain of Gabor filter bank
This Gabor algorithm in equation (2) discussed above, will be
use to implement a Gabor Filter in VHDL. This is basically
implementation of certain equations of the Gabor filter, shown
above, to provide an output (image segmentation) which gives
better results as compare to general image segmentation.
1) CORDIC ALGORITHM
CORDIC is a COordinate Rotation DIgital Computer
algorithm the set of shift-add algorithm collectively known as
CORDIC algorithm for computing a wide range of functions
including Trigonometric, hyperbolic, logarithmic and linear
functions. It is introduced in 1959 by Jack E. Volder.
As we observe the Gabor Filter equation, the implementation
is quite complex as the complex exponential term is present
there. This term is divided in two kernels. Even kernel is
cosine modulated and the odd kernel is sine modulated as e^j
= cos Q+ j sinQ and hence two filers are 90 degrees out of
phase. These trigonometric functions which are based on
vector rotations are implemented using Iterative shift & add
operation. No Multiplication is required and hence
Delay/Hardware cost is reduced comparable to division or
square rooting. It is Hardware Efficient Algorithm. The data
format consists of two 16-bit words which are used for the
even and odd kernels of Gabor filter equation. The 16-bit
words consist of a 4-bit integer part and 12- bit fractional part.
The image pixels are represented by an 8-bit number which is
stored in lookup table in do file format. This Gabor filter is
designed with CORDIC algorithm reduces the time required
for computation making the system fast.
2) IMAGE SEGMENTATION MODULE
This would apply the Gabor filter to the input image, and
provide a segmented output in the form
of a 2D array.
Fig.5 Segmented Healthy tonsils
Fig.6 Segmentation Disease affected tonsils
D. DISEASE DETECTION MODULE
Depending upon the output of image segmentation
module i.e. (a) the value in matrix showing total size of
disease affected area and (b) color of disease, this module will
detect if disease (Tonsillitis) is present in the input image or
not, and provide an output depicting the same highlighting
only tonsil area. The main concept used in this is to extract
only the overlapping area in given two images helps in
highlighting the disease area and gives the result in percentage
that how much percent the disease is present. With this we can
also able to identify the stage of disease by observing the
intensity value of pixel in each segment.

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E. VHDL OUTPUT MODULE
The output from step 4 would be stored in a text file and
an output file would be generated (figure (7)). This would
contain the actual output image.
Fig.7 Text File showing output
F. FINAL RESULT DISPLAY MODULE
This would be a simple MATLAB code named as post
file.m which would take the difference output from step 5 and
display it on the MATLAB screen in the form of a percentage.
Here it is showing 68.36% tonsillitis is detected as it is greater
than 60 % which is the limit of healthy tonsils.
Fig.8 MAT LAB showing final result
III. FLOW OF DESIGN
The overall design is revised in the flowchart shown
below in figure (9). It shows different Modules designed in
MATLAB (modules outside hashed lines) and VHDL
(modules inside hashed lines).
The image is captured using USB image sensor where it is
resized. Next the Gabor filter is applied to the image for
segmentation. This Gabor filter is designed with CORDIC
algorithm for computation & making the system fast.
The segmented image can be observed on image display
module within microseconds. The disease detection module,
which is designed in VHDL, compares the two images and
gives intensity values of disease affected area. This will be
helpful in identifying the stage of disease finding the
percentage of disease affected area.
IV. ANALYSIS AND DEVELOPMENT
In developing algorithm some considerations must be
taken, such as: properties and constraints. In software base,
these properties are: performance (accuracy and speed),
complexity, size of code, size of templates, difficulty of
development, dependency, and in hardware base these
properties are: performance, size of block/modules, and size of
templates. And in implementing software algorithm into
hardware base some constraints must be taking care, such as:
memory, component/block device, module dependency,
difficulty of development, interfacing and handshaking,
licensing, etc.
Initially the work will be simulated using VHDL and then
implemented on SPARTAN-3E FPGA. Figure (9): Data flow
of overall module.
Fig.9 Data flow of overall module
V. RESULTS AND DISCUSSION
The input images used here are the tonsils images. Instead
of this RGB image of tonsillitis we can use any RGB image of
skin disease as it is generalized algorithm with some changes.
The image size is fixed to 128 x 128. Thus each input image
will be resized and converted to grayscale image (figure (5)
(6)). This module generates 128 x 128 x 8 number of lines
showing the pixel values in V-sim format suitable to use in
Modelsim i.e. to interface VHDL code with MATLAB code.
Three Gabor filter for R, G & B are designed to filter each
component in image to give the noise free result. After
obtaining the segmented image as output using Gabor filter we
found that noise contents are reduced to great extent locating
the exact region of tonsil area. The pixel values of the input
image are obtained and provided serially to disease detection
module. Here the comparison is performed between two
samples giving the desired result in percentage as explained
above. This design further can be implemented on VERTEX /
SPARTAN-3E FPGA kit

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VI. CONCLUSIONS
In this paper, a concept of VLSI architecture for skin
related disease detection is proposed. It will improve data
transfer rates, provide efficient noise reduction, less power
consumption and require less memory storage. The Gabor
filter is an efficient tool to get all requirements as mentioned
above. The processing time required for simulation is very less
as compared to software simulation because of the use of
CORDIC algorithm, thus offers much greater speed than a
software implementation. This concept will be helpful in
detecting early stage of disease and saving the lives of
peoples.
REFERENCES
[I] T.Ratha Jeyalakshmi, K.Ramar, July 2009 “Segmentation
of Uterine Fibroid Using Morphology: An Automatic
Approach,” International conference on Intelligent Agent &
Multi-Agent Systems.
[II] S. J. Sangwine: October 2000 “Color image processing”
Electronics & communication engineering journal.
[III] Myung-Eun Lee', Soo-Hyung Kim', Sun-Worl Kim2 and
Sung-Ryul Ohl 2007 “Automatic Segmentation Methods
for Various CT Images Using Morphology Operation and
Statistical Technique” IEEE 3rd
International conference on
intelligent computer communication and processing
(ICCP).
[IV] Jia Xin-Wang, Ting Ting-Zhang, July 2009” CT Image
Segmentation by using a FHNN Algorithm Based on
Genetic Approach,” International conference on
Bioinformatics and Biomedical Engineering, pp.1-4.
[V] Thomas P.Weldon and William E. Huggins, 1999
“Designing Multiple Gabor Filters for Multi-Texture Image
Segmentation,” Optical Engineering, Vol. 38 No. 9, pp.
1478-1489.
[VI] Pranithan Phensadsaeng, Werapon Chiracharit and Kosin
Chamnongthai, 2009 IEEE “A VLSI Architecture of Color
Model-based Tonsillitis Detection’,”
[VII] Malarkhodi.S, Dr.R.S.D.Wahida Banu, Malarvizhi.M, 2010
Second “VLSI Implementation of Uterus Image
Segmentation Using Multi-Feature EM Algorithm Based
on Gabor Filter’,” International conference on Computing,
Communication and Networking Technologies

MEDICAL IMAGE SEGMENTATION FOR DISEASE DETECTION USING DIGITAL FILTER

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