A Facial Expression Recognition System A Project Report

Tribhuvan University
Institute of Science and Technology
Kathford International College of Engineering and Management
A Facial Expression Recognition System
A Project Report
Submitted To
Department of Science and Information Technology,
Kathford International College of Engineering and Management,
Balkumari, Lalitpur, Nepal
Submitted By
Nalina Matang (2203/069)
Shreejana Sunuwar (2218/069)
Sunny Shrestha (2228/069)
Sushmita Parajuli (2229/069)
Under the Supervision of
Mr. Ashok Kumar Pant
(Sr. Software Engineer, Innovisto Pvt. Ltd.)
Date: September 2016

ii
Institute Of Science and Technology
STUDENT’S DECLARATION
We, the undersigned solemnly declare that the report of the project work entitled
“FACIAL EXPRESSION RECOGNITION SYSTEM”, is based on our work carried
out during the course of study under the supervision of Mr. Ashok Kumar Pant.
We assert that the statements made and conclusions drawn are an outcome of the project
work. We further declare that, to the best of our knowledge and belief that the project
report does not contain any part of any work which has been submitted for the award of
any other degree/diploma/certificate in this University.
……………… ………………….
Ms. Nalina Matang Ms. Shreejana Sunuwar
(2203/069) (2218/069)
………………… ……………………
Ms. Sunny Shrestha Ms. Sushmita Parajuli
(2228/069) (2229/069)

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Supervisor’s Recommendation
I hereby recommend that this project work report is satisfactory in the partial fulfillment
for the requirement of Bachelor of Science in Computer Science and Information
Technology and be processed for the evaluation.
………………............................
Sr. Software engineer
Innovisto Pvt. Ltd.
(Supervisor)
Date:

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LETTER OF APPROVAL
This is to certify that the project prepared by Ms. Nalina Matang (2203/069), Ms.
Shreejana Sunuwar (2218/069), Ms. Sunny Shrestha (2228/069) and Ms. Sushmita
Parajuli (2229/069) entitled “FACIAL EXPRESSION RECOGNITION SYSTEM”
in partial fulfillment of the requirements for the degree of B.Sc. in Computer Science and
Information Technology has been well studied. In our opinion it is satisfactory in the
scope and quality as a project for the required degree.
………………............................
Department of Computer Science
and Information Technology
Kathford International College of
Engineering and Management
………………...........................
Sr. Software engineer
Innovisto Pvt. Ltd.
(Supervisor)
………………............................
(Internal Examiner)
………………............................
(External Examiner)

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ACKNOWLEDGEMENT
It is a great pleasure to have the opportunity to extend our heartfelt gratitude to everyone
who helped us throughout the course of this project. We are profoundly grateful to our
supervisor Mr. Ashok Kumar Pant, Sr. Software Engineer of Innovisto Pvt. Ltd., for his
expert guidance, continuous encouragement and ever willingness to spare time from his
otherwise busy schedule for the project’s progress reviews. His continuous inspiration has
made us complete this project and achieve its target.
We would also like to express our deepest appreciation to Mr. Sushant Poudel Head of
Department, Kathford International College of Engineering and Management,
Department of Computer Science and Information Technology, for his constant
motivation, support and for providing us with a suitable working environment. We would
also like to extend our sincere regards to Ms. Deni Shahi and all the faculty members for
their support and encouragement.
At last our special thanks go to all staff members of BSc CSIT department who directly
and indirectly extended their hands in making this project works a success.

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ABSTRACT
Facial Expression conveys non-verbal cues, which plays an important roles in
interpersonal relations. The Facial Expression Recognition system is the process of
identifying the emotional state of a person. In this system captured image is compared
with the trained dataset available in database and then emotional state of the image will
be displayed.
This system is based on image processing and machine learning. For designing a robust
facial feature descriptor, we apply the Local Binary Pattern. Local Binary Pattern (LBP)
is a simple yet very efficient texture operator which labels the pixels of an image by
thresholding the neighborhood of each pixel and considers the result as a binary number.
The histogram will be formed by using the operator label of LBP.
The recognition performance of the proposed method will be evaluated by using the
trained database with the help of Support Vector Machine. Experimental results with
prototypic expressions show the superiority of the LBP descriptor against some well-
known appearance-based feature representation methods.
We evaluate our proposed method on the JAFFE and COHN-KANADE dataset. The
Precision, Recall and Fscore from the COHN-KANADE dataset were 83.6142%,
95.0822% and 88.9955% respectively and that of JAFFE dataset were 91.8986%,
98.3649%, 95.0218% respectively. Experimental results demonstrate the competitive
classification accuracy of our proposed method.
Keywords:
Facial expression recognition (FER), Local Binary pattern (LBP), Support Vector
Machine (SVM)

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List of Figures
Figure 1: The eight expression from one subject.................................................................6
Figure 2: The seven expression from one subject................................................................6
Figure 3: Original Image......................................................................................................8
Figure 4: Cropped Image .....................................................................................................8
Figure 5: System Diagram .................................................................................................11
Figure 6: Flowchart of Training.........................................................................................12
Figure 7: Flowchart of Testing/Prediction.........................................................................13
Figure 9: Class Diagram ....................................................................................................14
Figure 10: Sequence Diagram............................................................................................15
Figure 11: The Basic LBP Operator ..................................................................................17
Figure 12: Two examples of extended LBP ......................................................................17
Figure 13: Experimental Demonstration from Image File.................................................33
Figure 14: Experimental Demonstration from Camera .....................................................35

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List of Tables:
Table 1: Data Collections.....................................................................................................7
Table 2: Confusion matrix of COHN-KANADE ..............................................................24
Table 3: Accuracy of COHN-KANADE ...........................................................................25
Table 4: Confusion matrix of JAFFE.................................................................................25
Table 5: Accuracy of JAFFE .............................................................................................26
Table 6: Dataset images of facial recognition....................................................................32

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Table of Contents
CHAPTER 1 ........................................................................................................................1
1. INTRODUCTION....................................................................................................1
1.1. Motivation .........................................................................................................2
1.2. Problem Statement.............................................................................................2
1.3. Objectives..........................................................................................................3
1.4. Scope and Applications .....................................................................................3
CHAPTER 2 ........................................................................................................................4
2. REQUIREMENT ANALYSIS.................................................................................4
2.1. Planning.............................................................................................................4
2.2. Literature Reviews.............................................................................................4
2.3. Data collection...................................................................................................5
2.3.1. COHN-KANADE AU Coded Facial Expression Database.......................5
2.3.2. Japanese Female Facial Expression (JAFFE) Database.............................6
2.4. Dataset Preparation............................................................................................7
2.5. Software Requirement Specification:................................................................8
2.5.1. Functional requirements:............................................................................8
2.5.2. Non-Functional requirements:....................................................................9
2.6. Feasibility Study................................................................................................9
Technical Feasibility ..................................................................................9
2.6.1.
Operational Feasibility...............................................................................9
2.6.2.
Economic Feasibility................................................................................10
2.6.3.
Schedule Feasibility .................................................................................10
2.6.4.
2.7. Software and Hardware Requirement..............................................................10
2.7.1. Software Requirement..............................................................................10
2.7.2. Hardware Requirement ............................................................................10
CHAPTER 3 ......................................................................................................................11
3. PROJECT METHODOLOGY...............................................................................11
3.1. System Design .................................................................................................11
System Diagram.......................................................................................11
3.1.1.
System Flowchart.....................................................................................12
3.1.2.
Class Diagram ..........................................................................................14
3.1.3.
Sequence Diagram....................................................................................15
3.1.4.
3.2. Phases in Facial Expression Recognition........................................................16
Image Acquisition ....................................................................................16
3.2.1.

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Face detection...........................................................................................16
3.2.2.
Image Pre-processing ...............................................................................16
3.2.3.
Feature Extraction ....................................................................................16
3.2.4.
3.2.4.1. Local Binary Pattern.............................................................................17
Classification............................................................................................18
3.2.5.
3.2.5.1. Support Vector Machines.....................................................................19
System Evaluation....................................................................................19
3.2.6.
a) Precision ..........................................................................................................20
b) Recall ...........................................................................................................20
c) F-score .............................................................................................................20
CHAPTER 4 ......................................................................................................................21
4. DEVELOPMENT AND TESTING.......................................................................21
4.1. Implementation Tools .........................................................................................21
4.1.1. Programming Language and Coding Tools .............................................21
4.1.2. Framework ...............................................................................................21
4.2. System Testing ................................................................................................22
4.2.1. Unit Testing..............................................................................................22
4.2.2. Integration Testing ...................................................................................22
CHAPTER 5 ......................................................................................................................24
5. EXPERIMENTATION AND RESULTS ..............................................................24
CHAPTER 6 ......................................................................................................................27
6. CONCLUSION AND RECOMMENDATION .....................................................27
6.1. Conclusion.......................................................................................................27
6.2. Future Scope....................................................................................................28
References..........................................................................................................................29
Appendix............................................................................................................................31
Datasets Collection ........................................................................................................32
Experimental Demonstration .........................................................................................33
Experimental Demonstration from Image File...........................................................33
Experimental Demonstration from Camera ...............................................................34

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CHAPTER 1
1. INTRODUCTION
A Facial expression is the visible manifestation of the affective state, cognitive activity,
intention, personality and psychopathology of a person and plays a communicative role in
interpersonal relations. It have been studied for a long period of time and obtaining the
progress recent decades. Though much progress has been made, recognizing facial
expression with a high accuracy remains to be difficult due to the complexity and
varieties of facial expressions [2].
Generally human beings can convey intentions and emotions through nonverbal ways
such as gestures, facial expressions and involuntary languages. This system can be
significantly useful, nonverbal way for people to communicate with each other. The
important thing is how fluently the system detects or extracts the facial expression from
image. The system is growing attention because this could be widely used in many fields
like lie detection, medical assessment and human computer interface. The Facial Action
Coding System (FACS), which was proposed in 1978 by Ekman and refined in 2002, is a
very popular facial expression analysis tool [3].
On a day to day basics humans commonly recognize emotions by characteristic features,
displayed as a part of a facial expression. For instance happiness is undeniably associated
with a smile or an upward movement of the corners of the lips. Similarly other emotions
are characterized by other deformations typical to a particular expression. Research into
automatic recognition of facial expressions addresses the problems surrounding the
representation and categorization of static or dynamic characteristics of these
deformations of face pigmentation [8].
The system classifies facial expression of the same person into the basic emotions namely
anger, disgust, fear, happiness, sadness and surprise. The main purpose of this system is
efficient interaction between human beings and machines using eye gaze, facial
expressions, cognitive modeling etc. Here, detection and classification of facial

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expressions can be used as a natural way for the interaction between man and machine.
And the system intensity vary from person to person and also varies along with age,
gender, size and shape of face, and further, even the expressions of the same person do
not remain constant with time.
However, the inherent variability of facial images caused by different factors like
variations in illumination, pose, alignment, occlusions makes expression recognition a
challenging task. Some surveys on facial feature representations for face recognition and
expression analysis addressed these challenges and possible solutions in detail [5].
1.1. Motivation
In today’s networked world the need to maintain security of information or physical
property is becoming both increasingly important and increasingly difficult. In countries
like Nepal the rate of crimes are increasing day by day. No automatic systems are there
that can track person’s activity. If we will be able to track Facial expressions of persons
automatically then we can find the criminal easily since facial expressions changes doing
different activities. So we decided to make a Facial Expression Recognition System.
We are interested in this project after we went through few papers in this area. The papers
were published as per their system creation and way of creating the system for accurate
and reliable facial expression recognition system.
As a result we are highly motivated to develop a system that recognizes facial expression
and track one person’s activity.
1.2. Problem Statement
Human emotions and intentions are expressed through facial expressions and deriving an
efficient and effective feature is the fundamental component of facial expression system.
Face recognition is important for the interpretation of facial expressions in applications
such as intelligent, man-machine interface and communication, intelligent visual
surveillance, teleconference and real-time animation from live motion images. The facial
expressions are useful for efficient interaction Most research and system in facial
expression recognition are limited to six basic expressions (joy, sad, anger, disgust, fear,

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surprise). It is found that it is insufficient to describe all facial expressions and these
expressions are categorized based on facial actions [7].
Detecting face and recognizing the facial expression is a very complicated task when it is
a vital to pay attention to primary components like: face configuration, orientation,
location where the face is set.
1.3. Objectives
1. To develop a facial expression recognition system.
2. To experiment machine learning algorithm in computer vision fields.
3. To detect emotion thus facilitating Intelligent Human-Computer Interaction.
1.4. Scope and Applications
The scope of this system is to tackle with the problems that can arise in day to day life.
Some of the scopes are:
1. The system can be used to detect and track a user’s state of mind.
2. The system can be used in mini-marts, shopping center to view the feedback of
the customers to enhance the business,
3. The system can be installed at busy places like airport, railway station or bus
station for detecting human faces and facial expressions of each person. If there
are any faces that appeared suspicious like angry or fearful, the system might set
an internal alarm.
4. The system can also be used for educational purpose such as one can get feedback
on how the student is reacting during the class.
5. This system can be used for lie detection amongst criminal suspects during
interrogation
6. This system can help people in emotion related -research to improve the
processing of emotion data.
7. Clever marketing is feasible using emotional knowledge of a person which can be
identified by this system.

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CHAPTER 2
2. REQUIREMENT ANALYSIS
2.1. Planning
In planning phase study of reliable and effective algorithms is done. On the other hand
data were collected and were preprocessed for more fine and accurate results. Since huge
amount of data were needed for better accuracy we have collected the data surfing the
internet. Since, we are new to this project we have decided to use local binary pattern
algorithm for feature extraction and support vector machine for training the dataset. We
have decided to implement these algorithms by using OpenCv framework.
2.2. Literature Reviews
Research in the fields of face detection and tracking has been very active and there is
exhaustive literature available on the same. The major challenge that the researchers face
is the non-availability of spontaneous expression data [1]. Capturing spontaneous
expressions on images and video is one of the biggest challenges ahead [2]. Many
attempts have been made to recognize facial expressions. Zhang et al investigated two
types of features, the geometry-based features and Gabor wavelets based features, for
facial expression recognition.
Appearance based methods, feature invariant methods, knowledge based methods,
Template based methods are the face detection strategies whereas Local Binary Pattern
phase correlation, Haar classifier, AdaBoost, Gabor Wavelet are the expression detection
strategies in related field [3]. Face reader is the premier for automatic analysis of facial
expression recognition and Emotient, Affectiva, Karios etc are some of the API's for
expression recognition. Automatic facial expression recognition includes two vital
aspects: facial feature representation and classifier problem [2].

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Facial feature representation is to extract a set of appropriate features from original face
images for describing faces. Histogram of Oriented Gradient (HOG), SIFT, Gabbor
Fitters and Local Binary Pattern (LBP) are the algorithms used for facial feature
representation [3,4]. LBP is a simple yet very efficient texture operator which labels the
pixels of an image by thresholding the neighborhood of each pixel and considers the
result as a binary number. The operator labels the pixels of an image by thresholding the
3X3 neighborhood of each pixel with the center value and considering the result as a
binary number [3]. HOG was first proposed by Dalal and Triggs in 2005. HOG numerates
the appearance of gradient orientation in a local path of an image.
For classifier problem we use algorithms like Machine learning, Neural Network, Support
Vector Machine, Deep learning, Naive Bayes. The formation of histogram by using any
of facial feature representation will use Support Vector Machine (SVM) for expression
recognition. SVM builds a hyperplane to separate the high dimensional space. An ideal
separation is achieved when the distance between the hyper plane and the training data of
any class is the largest [4].
The size of the block for the LBP feature extraction is chosen for higher recognition
accuracy. The testing results indicate that by using LBP features facial expressions
recognition accuracy is more than 97%. The block LBP histogram features extract local
as well as global features of face image resulting higher accuracy. LBP is compatible with
various classifiers, filters etc. [3].
2.3. Data collection
Some of the public databases to evaluate the facial expression recognition algorithms are:
2.3.1. COHN-KANADE AU Coded Facial Expression Database
Subjects in the released portion of the COHN-KANADE AU-Coded Facial Expression
Database are 100 university students. They ranged in age from 18 to 30 years. Sixty-five
percent were female, 15 percent were African-American, and three percent were Asian or
Latino. Subjects were instructed by an experimenter to perform a series of 23 facial
displays that included single action units and combinations of action units. Image

6
sequences from neutral to target display were digitized into 640 by 480 or 490 pixel
arrays with 8-bit precision for grayscale values. Included with the image files are
"sequence" files; these are short text files that describe the order in which images should
be read. The seven expressions are angry, surprise, contempt, fear, and disgust [4]. Fig.1
shows the 8 expressions with each from a different subject.
Figure 1: The eight expression from one subject
2.3.2. Japanese Female Facial Expression (JAFFE) Database
This database contains 213 images in total. There are 10 subjects and 7 facial expressions
for each subject. Each subject has about twenty images and each expression includes two
to three images. The seven expressions are angry, happy, disgust, sadness, surprise, fear
and neutral respectively [4]. Fig.2 shows the seven expressions from one subject.
Figure 2: The seven expression from one subject

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Table 1: Data Collections
Database Sample Details Available
Descriptions
COHN-KANADE
Database (also known
as CMU-Pittsburg data-
base) [1].
 585 image sequences from 97
subjects
 Age: 18 to 30 years
 Gender: 65% female
 Ethnicity: 15% African - Americans
and 3% of Asians and Latinos
“Annotation of
FACS Action
Units and emotion-
specified
expressions”
The Japanese Female
Facial Expression
(JAFFEE) Data-base
[1].
 213 images of 7 facial expressions (6
basic facial expressions + 1 neutral)
 10 Japanese female models.
“Each image has
been rated on 6
emotion adjectives
by 92 Japanese
subjects”
2.4. Dataset Preparation
The proposed system was trained and tested using two datasets namely COHN-KANADE
and JAFFE. The COHN-KANADE dataset consists of 500 images sequences from 100
subjects whereas the JAFFE dataset consists of 213 images. For our experiment we have
used 6481 images for training and 1619 images for testing fromm different subjects of
Cohn-Kanade dataset. Similarly, 107 images were used for training and 106 images were
used for testing from JAFFE dataset.
We normalized the faces to 72 pixels. Based on the structure of face facial images of
256*256 pixels were cropped from original images. To identify the facial image
automatic face detection was performed by using the face detector of our own system
based on Haar classifier. From the results of face detection including face location, face
width and face height were automatically created. Finally images were cropped in
accordance to the result given by the face detector and further cropped images were used
for training and testing.

8
Figures below show the original image and cropped image:
Figure 3: Original Image
Figure 4: Cropped Image
2.5. Software Requirement Specification:
Requirement analysis is mainly categorized into two types:
2.5.1. Functional requirements:
The functional requirements for a system describe what the system should do. Those
requirements depend on the type of software being developed, the expected users of the
software. These are statement of services the system should provide, how the system
should react to particular inputs and how the system should behave in particular situation.

9
2.5.2. Non-Functional requirements:
Nonfunctional requirements are requirements that are not directly concerned with the
specified function delivered by the system. They may relate to emergent system
properties such as reliability, response time and store occupancy. Some of the
nonfunctional requirements related with this system are hereby below:
a) Reliability:
Reliability based on this system defines the evaluation result of the system, correct
identification of the facial expressions and maximum evaluation rate of the facial
expression recognition of any input images.
b) Ease of Use:
The system is simple, user friendly, graphics user interface implemented so any can use
this system without any difficulties.
2.6. Feasibility Study
Before starting the project, feasibility study is carried out to measure the viable of the
system. Feasibility study is necessary to determine if creating a new or improved system
is friendly with the cost, benefits, operation, technology and time. Following feasibility
study is given as below:
Technical Feasibility
2.6.1.
Technical feasibility is one of the first studies that must be conducted after the project has
been identified. Technical feasibility study includes the hardware and software devices.
The required technologies (C++ language and CLion IDE) existed.
Operational Feasibility
2.6.2.
Operational Feasibility is a measure of how well a proposed system solves the problem
and takes advantage of the opportunities identified during scope definition. The following
points were considered for the project’s technical feasibility:
 The system will detect and capture the image of face.

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 The captured image is then (identified which category)
Economic Feasibility
2.6.3.
The purpose of economic feasibility is to determine the positive economic benefits that
include quantification and identification. The system is economically feasible due to
availability of all requirements such as collection of data from
 JAFFE
 COHN-KANADE
Schedule Feasibility
2.6.4.
Schedule feasibility is a measure of how reasonable the project timetable is. The system is
found schedule feasible because the system is designed in such a way that it will finish
prescribed time.
2.7. Software and Hardware Requirement
2.7.1. Software Requirement
Following are the software requirement necessary of the project:
a) C++ programming language
b) CLion IDE (selective)
c) OpenCV framework
d) Linux platform Ubuntu OS
2.7.2. Hardware Requirement
Following are the hardware requirement that is most important for the project:
a) Fluently working Laptops
b) RAM minimum 4Gb
c) Web Camera

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CHAPTER 3
3. PROJECT METHODOLOGY
3.1. System Design
System design shows the overall design of system. In this section we discuss in detail the
design aspects of the system:
System Diagram
3.1.1.
Training
Dataset
Face
Detection
Feature
Extraction
 LBP
Classification
 SVM
Learning
Model
Face
Detection
Feature
Extraction
 LBP
Classification
 SVM
Camera
Image
Video
Class 2:
Sad
Class 1:
Happy
Class 5:
Fear
Class 4:
Anger
Class 3:
Disgust
Class 6:
Surprise
Class 7:
Neutral
Testing
Datasets
Prediction
Labels
Figure 5: System Diagram

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System Flowchart
3.1.2.
Figure 6: Flowchart of Training
Start
Cropped Face and
aligned Dataset
Image Preprocessing
Feature Extraction
Training SVM
Trained Model

13
Figure 7: Flowchart of Testing/Prediction
Start
Input Image
Face Detection
Image Preprocessing
Feature Extraction
SVM
Trained Model
Recognition result

14
Class Diagram
3.1.3.
1..* 1
1 1 1 1..*
1 1
1..*
1
Figure 8: Class Diagram
FersCore
TRAIN_FILE: String
TEST_FILE:String
LABEL_FILE:String
MEAN_FILE: String
NUM_FEATURES_PER_GRIDS:Int
NUM_GRIDS:Size
Image_Size:Size
init()
setLabels()
train()
evaluate()
predict()
predictLabel()
calculateMean()
Fers
commands: string
modelPath: string
params: string
windowName: string
image: string
file: string
video: string
camera: int
display: bool
shuff: bool
detectModelFile: string
pause:int
displayDetections( )
fileMode( )
videoMode( )
cameraMode( )
imageMode( )
Evaluation
_avgAccuracy:double
_errRate:double
_precisionMicro:double
_recallMicro:double
_fScoreMicro:double
Evaluation ()
FeatureExtraction
Img:mat
Hist:mat
spatialHist:int
numPatterns:int
grid:size
images:<string,int>
convert()
computeLbpFeatures()
LBP()
Histogram()
spatialHistogram()
Detector
Cascade_:string
imgNewW:int
imgNewH_: int
minWH_: Size
scale_: double
minNeighbours_: int
padW_: int
padH_: int
cascadeFile_: string
detect( )
Confusion
_classes: int
_samples: int
_c: double
_per: double
_ind: string
_cm: int
convertToBooleanMatrix( )
confusion( )

15
Sequence Diagram
3.1.4.
Figure 9: Sequence Diagram
: Trainer : Tester : System
Input Images for Training
Update Images for Training
Delete Training Images
Trained model
Confusion matrix and Accuracy
Camera input images
Video input images
File text input images
Classification and
recognition of facial
expression
Begin

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3.2. Phases in Facial Expression Recognition
The facial expression recognition system is trained using supervised learning approach in
which it takes images of different facial expressions. The system includes the training and
testing phase followed by image acquisition, face detection, image preprocessing, feature
extraction and classification. Face detection and feature extraction are carried out from
face images and then classified into six classes belonging to six basic expressions which
are outlined below:
Image Acquisition
3.2.1.
Images used for facial expression recognition are static images or image sequences.
Images of face can be captured using camera.
Face detection
3.2.2.
Face Detection is useful in detection of facial image. Face Detection is carried out in
training dataset using Haar classifier called Voila-Jones face detector and implemented
through Opencv. Haar like features encodes the difference in average intensity in
different parts of the image and consists of black and white connected rectangles in which
the value of the feature is the difference of sum of pixel values in black and white regions
[6].
Image Pre-processing
3.2.3.
Image pre-processing includes the removal of noise and normalization against the
variation of pixel position or brightness.
a) Color Normalization
b) Histogram Normalization
Feature Extraction
3.2.4.
Selection of the feature vector is the most important part in a pattern classification
problem. The image of face after pre-processing is then used for extracting the important
features. The inherent problems related to image classification include the scale, pose,

17
translation and variations in illumination level [6]. The important features are extracted
using LBP algorithm which is described below:
3.2.4.1. Local Binary Pattern
LBP is the feature extraction technique. The original LBP operator points the pixels of
an image with decimal numbers, which are called LBPs or LBP codes that encode the
local structure around each pixel. Each pixel is compared with its eight neighbors in a
3 X 3 neighborhood by subtracting the center pixel value. In the result, negative
values are encoded with 0 and the others with 1. For each given pixel, a binary
number is obtained by merging all these binary values in a clockwise direction, which
starts from the one of its top-left neighbor. The corresponding decimal value of the
generated binary number is then used for labeling the given pixel. The derived binary
numbers are referred to be the LBPs or LBP codes [6].
Figure 10: The Basic LBP Operator
(P=8,R=1.0) (P=12,R=1.5)
Figure 11: Two examples of extended LBP
Binary:
11010011
Decimal:
211
Thresholding
5 9 1
7 2 3
4 4 6
1 1 0
1 0 0
1 1

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The limitation of the basic LBP operator is that its small 3×3 neighborhood cannot
capture the dominant features with large scale structures. As a result, to deal with the
texture at different scales, the operator was later extended to use neighborhoods of
different sizes [7]. Using circular neighborhoods and bilinearly interpolating the pixel
values allow any radius and number of pixel in the neighborhood. Examples of the
extended LBP are shown above (Figure 5.3.2), where (P, R) denotes sampling points
on a circle of radius of R.
Further extension of LBP is to user uniform patterns. A LBP is called uniform if it
contains at most two bitwise transitions from 0 to 1 or vice versa when the binary
string is considered circular. E.g.00000000, 001110000 and 11100001 are uniform
patterns. A histogram of a labelled image f1(x, y) can be defined as
Hi = ∑ I fl x, y = i , i = , … , n −
, (1)
Where n is the number of different labels produced by the LBP operator and
I A = {
A is true
A is false
(2)
This histogram contains information about the distribution of the local micro-patterns,
such as edges, spots and flat areas, over the whole image. For efficient face
representation, feature extracted should retain also spatial information. Hence, face
image is divided into m small regions R0, R1,…,Rm and a spatially enhanced
histogram is defined as [2]
Hi = ∑ I fl x, y = i I x, y ϵRj
, (3)
Classification
3.2.5.
The dimensionality of data obtained from the feature extraction method is very high so it
is reduced using classification. Features should take different values for object belonging
to different class so classification will be done using Support Vector Machine algorithm.

19
3.2.5.1. Support Vector Machines
SVM is widely used in various pattern recognition tasks. SVM is a state-of-the-art
machine learning approach based on the modern statistical learning theory. SVM can
achieve a near optimum separation among classes. SVMs is trained to perform facial
expression classification using the features proposed. In general, SVM are the
maximal hyperplane classification method that relies on results from statistical
learning theory to guarantee high generalization performance.
Kernel functions are employed to efficiently map input data which may not be
linearly separable to a high dimensional feature space where linear methods can then
be applied. SVMs exhibit good classification accuracy even when only a modest
amount of training data is available, making them particularly suitable to a dynamic,
interactive approach to expression recognition [10].
An ideal separation is achieved when the hyper plane and the training data of any
class is the largest. This separating hyper plane works as the decision surface. SVM
has been successfully employed for a number of classification tasks such as text
categorization, genetic analysis and face detection [11].
Given a training set of labeled samples:
� = { �, �| � ϵ��
, �ϵ{− , }} �
�=
(1)
A SVM tries to find a hyperplane to distinguish the samples with the smallest errors.
. − = (2)
For an input vector xi, the classification is achieved by computing the distance from
the input vector to the hyperplane. The original SVM is a binary classifier [4].
System Evaluation
3.2.6.
Evaluation of the system can be done using following methods:

20
a) Precision
Precision estimates the predictive value of a label, either positive or negative, depending
on the class for which it is calculated; in other words, it assesses the predictive power
of the algorithm. Precision is the percentage of correctly assigned expressions in relation
to the total number of aspects.
� � =
+
b) Recall
Recall is a function of its correctly classified examples (true positives) and its
misclassified examples (false negatives). Recall is the percentage of correctly assigned
expressions in relation to the total number of expressions.
=
+
c) F-score
F-score is a composite measure which benefits algorithms with higher sensitivity and
challenges algorithms with higher specificity. The F-score is evenly balanced when β = 1.
It favours precision when β > 1, and recall otherwise.
� − =
� + ∗ � � ∗
� ∗ � � ∗
All three measures distinguish the correct classification of labels within different classes.
They concentrate on one class (positive examples). Hence, precision and recall do
measure different properties and we therefore need a combined quality measure in order
to determine the best matching aspect to expression category mappings. The so called F-
measure fm computes the harmonic mean of precision and recall and allows taking into
account both properties at the same time [9]. Note that the overall recall recallov is also
known as accuracy.

21
CHAPTER 4
4. DEVELOPMENT AND TESTING
4.1. Implementation Tools
4.1.1. Programming Language and Coding Tools
a) C++
C++ is a general-purpose programming language. It has imperative, object-oriented and
generic programming features, while also providing facilities for low-
level memory manipulation. It was designed with a bias toward system
programming and embedded, resource-constrained and large systems, with performance,
efficiency and flexibility of use as its design highlights. C++ has also been found useful
in many other contexts, with key strengths being software infrastructure and resource-
constrained applications, including desktop applications, servers (e.g. e-commerce, web
search or SQL servers), and performance-critical applications (e.g. telephone
switches or space probes). C++ is a compiled language, with implementations of it
available on many platforms and provided by various organizations, including the Free
Software Foundation (FSF's GCC), LLVM, Microsoft, Intel and IBM.
b) IDE CLion for C++
CLion is a cross-platform C/C++ IDE which is more than just an editor as it offers
intelligent Cmake support. CLion helps in knowing codes through and through and can
boost the productivity with smart and relevant code completion, instant navigation and
reliable refactoring.
4.1.2. Framework
a) OpenCV
OpenCV (Open Source Computer Vision Library) is an open source computer vision and
machine learning software library. OpenCV was built to provide a common infrastructure
for computer vision applications and to accelerate the use of machine perception in the

22
commercial products. Being a BSD-licensed product, OpenCV makes it easy for
businesses to utilize and modify the code.
The library has more than 2500 optimized algorithms, which includes a comprehensive
set of both classic and state-of-the-art computer vision and machine learning algorithms.
These algorithms can be used to detect and recognize faces, identify objects, classify
human actions in videos, track camera movements, track moving objects, extract 3D
models of objects, produce 3D point clouds from stereo cameras, stitch images together to
produce a high resolution image of an entire scene, find similar images from an image
database, remove red eyes from images taken using flash, follow eye movements,
recognize scenery and establish markers to overlay it with augmented reality, etc. It has
C++, C, Python, Java and MATLAB interfaces and supports Windows, Linux,
Android and Mac OS.
4.2. System Testing
System testing was done by giving different training and testing datasets. This test was
done to evaluate whether the system was predicting accurate result or not. During the
phase of the development of the system our system was tested time and again.
The series of testing conducted are as follows:
4.2.1. Unit Testing
In unit testing, we designed the whole system in modularized pattern and each module
was tested. Till we get the accurate output from the individual module we worked on the
same module.
4.2.2. Integration Testing
After constructing individual modules all the modules were merged and a complete
system was made. Then the system was tested whether the prediction given by training
dataset to testing set was correct or not. We tried to meet the accuracy as higher as much
as we can get. After spending a couple of days in integration testing the average accuracy
of our system was 91%.

23
4.2.2.1. Alpha testing
Alpha testing is the first stage of software engineering which is considered as a
simulated or actual operational testing done by the individual member of the project.
Alpha testing is conducted by the project developers, in context of our project.
4.2.2.2. Beta Testing
Beta testing comes continuously after alpha testing which is considered as a form of
external user acceptance testing. The beta version of the program is developed to and
provided to limited audience. This is the final test process in the case of this project.
In this system the beta-testing is done by our colleagues and the project supervisor.

24
CHAPTER 5
5. EXPERIMENTATION AND RESULTS
The aim of this project work is to develop a complete facial expression recognition
system. Two datasets, COHN_KANADE and JAFFE were used for the experimentations.
First of all, system was trained using different random samples in each dataset by
supervised learning. In each datasets the data were partitioned into two parts for training
and testing. Every dataset have completely different samples which are selected randomly
in uniform manner from the pool of given dataset. The COHN_KANADE datasets
included 585 directories of both subject and session where there were 97 subject
directories and 8795 image files in total and partitioned was made in the ratio of 8:2 i.e.
6481 (80%) for train and 1619 (20%) for test. Similarly, JAFFE dataset included 213
images which was partitioned in the ratio of 7.5:2.5 i.e. 160 (75%) for train and 53 (25%)
for test.
The confusion and accuracy evaluation results of COHN-KANADE and JAFFE datasets
are as below:
Table 2: Confusion matrix of COHN-KANADE
Labels Angry Disgust Fear Happy Neutral Sad Surprise
Angry 259 0 0 0 0 1 0
Disgust 1 182 0 0 0 0 0
Fear 2 1 219 0 0 0 1
Happy 25 40 173 98 1 19 0
Neutral 1 1 12 0 111 0 0
Sad 1 1 1 1 0 228 0
Surprise 12 15 141 1 0 11 60
In the above table, row shows the actual classes and column shows the predicted classes.
The classifier made a total of 1619 predictions where the classifier predicted angry for

25
300 times , disgust for 239 times, fear for 545 times, happy for 99 times, neutral for 112
times, sad for 259 times and surprise for 61 times. Whereas in reality 260 cases was
angry, 183 was disgust, 223 was fear, 356 was happy, 125 was neutral, 228 was sad and
240 was surprise.
Table 3: Accuracy of COHN-KANADE
Evaluation Types Results Percentages
Precision 83.6412
Recall 95.0822
F-score 88.9955
The above table shows that 83.6412% of the expressions were predicted 95.0822% of the
expressions were correctly assigned. The harmonic mean of precision and recall was
88.9955%.
Table 4: Confusion matrix of JAFFE
Labels Angry Disgust Fear Happy Neutral Sad Surprise
Angry 4 1 0 0 0 1 0
Disgust 0 6 0 0 0 0 0
Fear 0 0 10 0 0 0 0
Happy 0 0 0 10 2 0 0
Neutral 0 0 0 0 6 0 0
Sad 0 0 0 0 0 10 0
Surprise 0 0 0 0 1 0 2
In the above table, row shows the actual classes and column shows the predicted classes.
The classifier made a total of 53 predictions where the classifier predicted angry for 4
times, disgust for 7 times, fear for 10 times, happy for 10 times, neutral for 9 times, sad
for 11 times and surprise for 2 times. Whereas in reality 6 cases were angry, 6 was
disgust, 10 was fear, 12 was happy, 6 was neutral, 10 was sad and 3 was surprise.

26
Table 5: Accuracy of JAFFE
Evaluation Types Percentages
Precision 91.8986
Recall 98.3649
F-score 95.0218
The above table shows that 91.8986% of the expressions were predicted, 98.3649% of the
expressions were correctly assigned. The harmonic mean of precision and recall was
95.0218%.

27
CHAPTER 6
6. CONCLUSION AND RECOMMENDATION
6.1. Conclusion
This project proposes an approach for recognizing the category of facial expressions.
Face Detection and Extraction of expressions from facial images is useful in many
applications, such as robotics vision, video surveillance, digital cameras, security and
human-computer interaction. This project’s objective was to develop a facial expression
recognition system implementing the computer visions and enhancing the advanced
feature extraction and classification in face expression recognition.
In this project, seven different facial expressions of different persons’ images from
different datasets have been analyzed. This project involves facial expression
preprocessing of captured facial images followed by feature extraction using feature
extraction using Local Binary Patterns and classification of facial expressions based on
training of datasets of facial images based on Support Vector Machines. This project
recognizes more facial expressions based on JAFFE, COHN-KANADE face database. To
measure the performance of proposed algorithm and methods and check the results
accuracy, the system has been evaluated using Precision, Recall and Fscore. The same
datasets were used for both training and testing by dividing the datasets into training
samples and testing samples in the ratio of 8:2 of COHN-KANADE and 7.5:2.5 of
JAFFE. The Precision, Recall and Fscore from the COHN-KANADE dataset were
83.6142%, 95.0822% and 88.9955% respectively and JAFFE dataset were 91.8986%,
98.3649% and 95.0218% respectively.
Experiment results on two databases, JAFFE and the COHN-KANADE dataset, show
that our proposed method can achieve a good performance. Facial expression recognition
is a very challenging problem. More efforts should be made to improve the classification
performance for important applications. Our future work will focus on improving the
performance of the system and deriving more appropriate classifications which may be
useful in many real world applications.

28
6.2. Future Scope
Face expression recognition systems have improved a lot over the past decade. The focus
has definitely shifted from posed expression recognition to spontaneous expression
recognition. Promising results can be obtained under face registration errors, fast
processing time, and high correct recognition rate (CRR) and significant performance
improvements can be obtained in our system. System is fully automatic and has the
capability to work with images feed. It is able to recognize spontaneous expressions. Our
system can be used in Digital Cameras wherein the image can be captured only when the
person smiles. In security systems which can identify a person, in any form of expression
he presents himself. Rooms in homes can set the lights, television to a person’s taste
when they enter the room. Doctors can use the system to understand the intensity of pain
or illness of a deaf patient. Our system can be used to detect and track a user’s state of
mind, and in mini-marts, shopping center to view the feedback of the customers to
enhance the business etc.

29
References
[1] Bettadapura, V. (2012). Face expression recognition and analysis: the state of the
art. arXiv preprint arXiv:1203.6722.
[2] Shan, C., Gong, S., & McOwan, P. W. (2005, September). Robust facial
expression recognition using local binary patterns. In Image Processing, 2005.
ICIP 2005. IEEE International Conference on (Vol. 2, pp. II-370). IEEE.
[3] Bhatt, M., Drashti, H., Rathod, M., Kirit, R., Agravat, M., & Shardul, J. (2014). A
Studyof Local Binary Pattern Method for Facial Expression Detection. arXiv
preprint arXiv:1405.6130.
[4] Chen, J., Chen, Z., Chi, Z., & Fu, H. (2014, August). Facial expression
recognition based on facial components detection and hog features. In
International Workshops on Electrical and Computer Engineering Subfields (pp.
884-888).
[5] Ahmed, F., Bari, H., & Hossain, E. (2014). Person-independent facial expression
recognition based on compound local binary pattern (CLBP). Int. Arab J. Inf.
Technol., 11(2), 195-203.
[6] Happy, S. L., George, A., & Routray, A. (2012, December). A real time facial
expression classification system using Local Binary Patterns. In Intelligent Human
Computer Interaction (IHCI), 2012 4th International Conference on (pp. 1-5).
IEEE.
[7] Zhang, S., Zhao, X., & Lei, B. (2012). Facial expression recognition based on
local binary patterns and local fisher discriminant analysis. WSEAS Trans. Signal
Process, 8(1), 21-31.

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[8] Chibelushi, C. C., & Bourel, F. (2003). Facial expression recognition: A brief
tutorial overview. CVonline: On-Line Compendium of Computer Vision, 9.
[9] Sokolova, M., Japkowicz, N., & Szpakowicz, S. (2006, December). Beyond
accuracy, F-score and ROC: a family of discriminant measures for performance
evaluation. In Australasian Joint Conference on Artificial Intelligence (pp. 1015-
1021). Springer Berlin Heidelberg.
[10] Michel, P., & El Kaliouby, R. (2005). Facial expression recognition using support
vector machines. In The 10th International Conference on Human-Computer
Interaction, Crete, Greece.
[11] Michel, P., & El Kaliouby, R. (2003, November). Real time facial expression
recognition in video using support vector machines. In Proceedings of the 5th
international conference on Multimodal interfaces (pp. 258-264). ACM.

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Datasets Collection
Table 6: Dataset images of facial recognition
Happy
Sad
Angry
Surprise
Disgust
Fear
Neutral

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Experimental Demonstration
Experimental Demonstration from Image File
Figure 12: Experimental Demonstration from Image File

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Experimental Demonstration from Camera

35
Figure 13: Experimental Demonstration from Camera

A Facial Expression Recognition System A Project Report

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