video tracking system based on computer vision

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    VIDEO TRACKING SYSTEM

    BASED ON COMPUTER VISION

    MASTER DOMAIN: INFORMATION

    PROCESSING IN COMMUNICATIONSAND MULTIMEDIA

    MASTERS DEGREE PROJECT

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    SUMMARY

    1. INTRODUCTION

    2. ANALYSIS

    3. IMPLEMENTING

    4. TESTING AND EXPERIMENTAL RESULTS

    5. CONCLUSIONS

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    1. INTRODUCTION

    1.1 Context and motivation BIOMETRICS - a relatively new connotation

    The human face recognition

    1.2 General outlook

    Potential detection solutions:1. using a single colour background

    2. searching a particular area of colour

    3. working with an image in different shades of grey

    4. the extraction of the backgroundPotential tracking solutions:1. background extraction

    2. pixel temporal differentiation

    3. optical flow method

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    2. ANALYSIS

    The main conditions for the detection solution: detection independence detection must be done also in the case of noisy images detection should be fast and repeated during tracking.

    The conditions for the tracking algorithm:

    least influence by unclear image due to motion blur or on falsedetection solving possible background differences from one frame to

    another ability to operate during different light intensity not being influenced by background changes or displacements must to follow the detected face in a center-stage position,

    without being influenced by other faces detected in thebackground area

    must to offer the possibility to compress the images as videofiles

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    Human face detection

    Diagram representation

    of a detection cascade

    The first two features

    selected by the

    AdaBoost algorithm

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    Face tracking process

    It is proposed that the tracking process to be performedthrough foreground face detection.

    r2

    P2(x2,y2)

    rn

    Pn(xn,yn)

    r1

    r0

    P1(x1,y1)

    y

    x

    dn

    d2

    d1

    P0(x0,y0)

    C(X,Y)

    P(x,y)

    y

    x

    Center of

    the image

    To resolve multiple detection

    case, there are two

    proposed selection criteria:

    Maximum face area

    r = max(r1, r2, ... , rn)

    Minimum distance between the mass

    center of the detected face within the

    previous stage and the mass center of

    the faces detected in the current stage

    d = min(d1, d2, ... , dn)

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    Communication

    The proposed

    system is aimed atdetecting andtracking faces fromdistance, from theInternet.

    Such a system isendowed with thefeatures of twosystems already

    known, that are: human-machine

    interfaces

    the IP cameras

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    Hardware

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    Disigning the User interface

    User interface and the capture and tracking module, as well as

    microcontroller operation mode - Command operation module

    main

    topLeft

    middleLeft

    Menu

    Commands

    middleRight

    Vertical

    Commands

    topMiddle topRight

    middle

    middleMiddle

    Video Content

    middleBottom

    Horizontal Commands

    Video Capture & Tracking

    Command ModuleSerial Command Module

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    Designing the video processingsystem

    mencoderconvert(ImageMagic)

    JPEG

    AVI

    BMP

    BMP

    BMP JPEG

    JPEG

    JPEGcompression

    MPEGcompression

    videocapture

    OpenCV

    1. INPUT

    2. MAIN

    3. LOOP

    4. DETECT & DRAW

    5. TIMING

    START

    STOP

    The program was splitted in blocks,according to the type of performedoperations

    Stages of image processing in the face tracking system

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    TESTING AND EXPERIMENTALRESULTS

    Determining the maximum speed of a face in the detection

    process

    Hitec HS-300 servo specifications:

    speed s= 60 degrees /0.19 s

    step= 0.36 degrees

    = /(t + t)

    where t = /s

    rr

    X = L 2r

    L

    The diminished space

    X = L-2r

    = (L-2r)A/L

    = /tv tv= /

    tv = time of view

    A

    rr L-2r

    t t

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    Graphical representation of the frame rate

    0

    1

    2

    3

    4

    5

    6

    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

    Input Frame Rate

    Angular Speed

    Average Frame Rate

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    -0.2

    0

    0.2

    0.4

    0.6

    0.8

    1

    1.2

    1.4

    1.6

    1.8

    1 2 3 4 5 6 7 8 9 101112131415161718192021222324

    FPS

    DetectionTime

    Detections

    False detections

    Graphical representation of a test (20 sec) for the angular speed of

    0.389293 rad/sec (applied delay: 15 milliseconds/period)

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