Interational Conference on Communication and Signal Processing, April 3-5, 2014, India
A Comparative Analysis of Edge and Color Based
Segmentation for Orange Fruit Recognition
R. Thendral, A. Suhasini, and N. Senthil
Abstract-In this paper, we presented two segmentation
methods. Edge based and color based detection methods were
used to segment images of orange fruits obtained under natural
lighting conditions. Twenty digitized images of orange fruits were
randomly selected from the Internet in order to fnd an orange in
each image and to determine its location. We compared the
results of both segmentation results and the color based
segmentation outperforms the edge based segmentation in all
aspects. The MATLAB image processing toolbox is used for the
computation and comparison results are shown in the segmented
image results.
Index Terms- color based segmentation, edge based
segmentation, machine vision, Orange harvesting.
I. INTRODUCTION
Fresh fuit harvesting is a sensitive operation. According to
the [1] cost of harvesting by labors is very expensive and time
consuming. In addition, picking of fuits by hand is very
tedious. To solve these problems, human works can be
replaced by automatic robots. Automatic harvesting operations
reduce the harvesting costs. Therefore, automation and use of
image processing methods in agriculture have become a major
issue in recent years [2] - [4].
Jimenez et al. [5] presented a review of fuit recognition
systems. Schertz and Brown [6] considered both individual
fuit harvest and mass harvest. The fuit surface was identifed
by photometric comparison. They reported that ten times more
light refected fom a fuit than fom a leaf Parrish and Goksel
[7] reported an experimental automated apple harvesting
system in a laboratory. They used different green and red
optical flters and a black-and-white TV camera to obtain
images for apple orchard and developed an automated
experimental system for harvesting apple. Problems
accompanying with mechanical harvesting resulted in the
development of robotic harvesting methods, thereby prototype
machine vision based harvesters has been increasingly being
developed. Several studies have been carried out to design a
harvesting robot to pick up fuits fom the trees or plants [8 -
12]. Bulanon and Kataoka [13] developed an algorithm for
R. Thendral is with the Department of Computer Science and Engineering,
Research scholar, Annamalai University, Annamalai Nagar, Chidambaram (e·
mail: thendralamutha@gmail. com).
A. Suhasini is with the Department of Computer Science and Engineering,
Associate Professor, Annamalai University, Annamalai Nagar, Chidambaam
(e-mail: suha_babu@yahoo.com).
N. Senthil is with the Department of Computer Science and Engineering,
PG Student,Annamalai University,Annamalai Nagar, Chidambaram (e-mail:
engzenthil@gmail. com).
978-1-4799-3358-7114/$31.00 ©2014 IEEE
the automatic recognition of ripe Fuji apples fom the tree;
they enhanced the difference between fuit fom other objects
within the image, based on the difference between luminance
and red color (R-Y). Hanan et al. [14] developed a vision
system to pick orange using a harvesting robot. The
RI(R+G+B) feature was used for recognition of orange fuits
on the tree. The automated harvesting system [15] should
perform the following operations: (1) recognize and locate the
fuit; (2) reach for the fuit; (3) detach the fuit without causing
damage both to the fuit and the tree; and (4) move easily in
the orchard. There are an increasing number of robotics
applications aimed at detecting fuits fom images or videos
[16 - 19].
The frst major task of a harvesting robot is to recognize and
localize the fuit on the tree. This paper focuses on recognition
of orange fuits by using edge and color based segmentation
methods and we compare the results of both segmentation
results. In the next section the details of our proposed edge and
color based segmentation methods are presented. The results
and discussion is given in section III. Finally, in section IV,
conclusions of the proposed approach were presented.
II. MATERIALS AND METHODS
Twenty digitized images of orange fuits were randomly
selected fom the Interet and all the images are of different
pixel size. These images were captured in different lighting
conditions with different background and different camera
distances.
A. Image Processing Algorithm
The input sectional tree images were having different
lighting conditions. The fuit regions in many images were
under the shadow of the leaves and branches. Recognition is
the process of separating an object of interest fom the
background. This is an image processing procedure called
segmentation [20]. In order to segment the acquired images,
two algorithms were developed: edge based and color based
segmentation.
B. Edge Detection Based Algorithm
The Canny edge detector [21] is a popular method for
fmding edges that begins by smoothing an image by
convolving it with a Gaussian of a given sigma value. Based
on the smoothed image, derivatives in both the x and y
direction are computed; these in turn are used to compute the
gradient magnitude of the image. Once the gradient magnitude
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