INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 8, ISSUE 12, DECEMBER 2019 ISSN 2277-8616
3634
IJSTR©2019
www.ijstr.org
Filtering Of Faded Coffee Beans Using Image
Processing
Albert John G. Gonzales, John Anthony D. Sosa, Edwin R. Arboleda, Elbert M. Galas
Abstract: Faded defect coffee beans have alterations in the normal color due to iron deficiency in the soil, excessive time in the dryer, or if it is stored for
a long time. The research aims to use image processing to differentiate and filter faded coffee beans from the quality coffee beans. A set of a quality
coffee bean is used as a reference for color thresholding to identify which coffee bean is faded. It is then removed from the image, leaving only the
quality coffee beans. The image processing done had successfully filtered out the faded coffee beans from the quality ones.
Index Terms: Coffee, Image Processing, Thresholding, Faded Defect
—————————— ——————————
1. INTRODUCTION
One of the most valued and significant beverage in this world
is coffee [1]. Better quality beverages are associated with
more equilibrated sensorial attributes[2]. Coffee bean's cost
relies on its quality, which directly correlates with its final
product's flavor[3]. There are many factors affecting the quality
of the coffee. The quality of coffee beans is traditionally
determined by subjective visual inspection, which requires
significant effort and time and is susceptible to error [4]. Every
coffee bean sample is evaluated by its condition, appearance,
and size [5]. The typical way to determine the best coffee bean
is by its color. For green coffee beans, color variation is a
powerful indication of the occurrence of oxidative processes
and natural enzymic biochemical transformations that change
the structure of the beans responsible for the flavor and
fragrance of the coffee[6], [7]. Visual inspection quickly
assesses the kinds of coffee beans and their quality. But
human-inspectors ' decision-making capacity is subject to
external factors such as fatigue, atmosphere, light, emotion,
bias, etc[3].
One of the crucial points is the harvesting period, it is essential
to have techniques to produce good quality coffee, the degree
of coffee fruit ripeness and the prevention of mold
contamination during harvesting, drying, and storing of the
seeds.[8]. After picking, coffee beans are sun-dried for about
20 days and due to some external factors some of the
beans might be damaged [9], [10].Another important process
that affects the bean quality is the roasting, it is the chemical
process consisting of heating and evaporation of moisture in
the coffee that changes the color and flavor of it [11].Without
proper processes, the quality of a coffee bean could decrease
and ultimately be a defect. Uneven drying or re-wetting after
drying, storing in bad conditions storage, long time in storage,
excessive time in the dryer, or high temperature during drying,
all of which can lead to a ―Faded‖ coffee bean, where it loses
its color which is undesirable. By using Matlab the faded
coffee bean can be identified and be separated from the good
quality coffee beans. MATLAB is the simplest and widely used
software in Image processing. In the Image processing
algorithm, information can be extracted and also diseases can
be determined, etc. It has been used in many areas, including
radar systems, medical science, remote sensing, air traffic
control systems, and forensic sciences [12]–[16]. Image
processing toolbox based on MATLAB offers a broad range of
referenced algorithms, techniques and apps for image
processing, visualization, and segmentation. MATLAB takes
each input as a matrix and performs an image-based
algorithm[17]–[19]. MATLAB analyzes the RGB values for
every pixel efficiently used for image processing [20]. It could
also be used not only to discriminate against a coffee's black
bean defects but also to address other color-related quality
flaws [21]. RGB is the acronym for colors red, green, and blue.
The resulting color is produced by these spectral components
[22]. Color Thresholding is another commonly used tool in
MATLAB Image processing. The color thresholding function is
to separate an image into the region according to the
predefined criteria [23], [24],[25]. By finding the RGB of a good
quality coffee bean a comparison between the RGB values of
the sampled coffee bean and the coffee beans to be tested
can be done. The comparison can then determine which
coffee bean is faded and which is not, and then filter the faded
coffee bean out of the image, leaving only the good quality
coffee beans.
2 MATERIALS AND METHODS
2.1 Review Stage
The purpose of this study is to make a series of codes that will
determine and filter a faded defect coffee bean to a quality
one. The filtering of the faded defect coffee bean was made
using color thresholding and a set of codes done in the
software Matlab. Figure 1 shows an image of a set of coffee
beans to be tested and filtered. The bean on the third row, the
fifth column has a faded skin. The researchers aim to remove
it from the image after it was analyzed, leaving only the normal
ones.
————————————————
Albert John G. Gonzales is from the Department of Computer and
Electronics Engineering,College of Engineering and Information
Technology, Cavite State University, Indang, Cavite.
John Anthony D. Sosa is from the Department of Computer and
Electronics Engineering, College of Engineering and Information
Technology,Cavite State University, Indang, Cavite.
Edwin R. Arboleda is from the Department of Computer and
Electronics Engineering, College of Engineering and Information
Technology,Cavite State University, Indang, Cavite. E-mail:
edwin.r.arboleda@cvsu.edu.ph
Elbert M. Galas is from the Information Technology Department,
College of Computing, Pangasinan State University-Urdaneta
Campus