74 6. <strong>SOFT</strong> <strong>BIOMETRICS</strong> FOR QUANTIFYING AND PREDICTING <strong>FACIAL</strong> AESTHETICSaesthetics respectively.Table 6.1: Characteristics listed in decreasing order with respect to theabsolute Pearson’s correlation coefficient, related Pearson’s correlationcoefficients and related -model weights, see Figure 6.3 and Figure 6.4for notations <strong>of</strong> facial measuresTrait xiPearson’scorrelationcoefficient -Modelweightri,MOSx1. Ratio (eye height / head length) 0.5111f/a18.3506x2. Ratio (head width / head length) 0.4487b/a4.5780x3. Eye make up 0.3788 0.3055x4. Face shape 0.3521 0.1606x5. Eye Brow shape 0.2523 0.3337x6. Fullness <strong>of</strong> Lips 0.2242 0.2019x7. Ratio (from top <strong>of</strong> head to nose / 0.2198head length) (d+c)/a-17.8277x8. Glasses -0.2095 -0.6707x9. Lipstick 0.1997 0.0502x10. Skin goodness -0.1856 -0.3930x11. Hair Length / Style -0.1851 -0.0657x12. Ratio (from top <strong>of</strong> head to mouth 0.1818/ head length) (d+c+e)/a-4.1919x13. Ratio (from top <strong>of</strong> head to eye / 0.1774head length) d/a49.3939x14. Image format 0.1682 0.1695x15. Ratio (eye width / distance 0.1336 0.8982between eyes) (h-i)/(2.i)x16. Ratio (from nose to chin / eye to -0.1204 0.0970nose) (a-d-c)/cx17. Left eye distance to middle <strong>of</strong> 0.1183image or to mass point0.4197x18. Right eye distance to middle <strong>of</strong> 0.1155 0.2042image or to mass pointx19. Ratio (from top <strong>of</strong> head eye / eye -0.1012 -1.0091to nose) d/cx20. Image Resolution 0.1012 -0.3493x21. Expression -0.0913 -0.3176x22. Ratio (outside distance between -0.0833 -1.7261eyes / top <strong>of</strong> the head to eye) h/dx23. JPEG quality measure 0.0802 0.9007x24. Eyes symmetry, 0.93
75A direct way to find a relationship between the MOS and each <strong>of</strong> the 37 traits is using Pearson’scorrelation coefficient. We remind the reader that for two vectors, X = x 1 ,x 2 ,...,x n andY = y 1 ,y 2 ,...,y n , the Pearson’s correlation coefficient is given byr X,Y = cov(X,Y)σ X σ Y= E[(X −µ X)(Y −µ Y )]σ X σ Y, (6.1)where σ X and σ Y are being the standard deviations for X and Y , respectively. The coefficientranges between −1 and 1, with the two extreme points being obtained when the variables aremaximally linearly related.Pearson’s correlation coefficients are calculated for all 37 vectors, each vector correspondingto a feature. Per feature, a 260-values X vector describes each feature for each one <strong>of</strong> the 260training images 1 . The 260–values vector Y describes each image related MOS rating. Table 6.1itemizes these coefficients in decreasing order <strong>of</strong> importance with respect to the absolute Pearson’scorrelation coefficient.6.4.2 Insight provided from empirical dataThe first notable result reveals the strong correlation between the best ranked traits and theMOS, which even exceeds a Pearson’s correlation coefficient <strong>of</strong> 0.5 for the trait ’ratio eyeheight/face-height’.Particularly in regard to an automatic MOS prediction image processing toolthese results are very encouraging. Further we observe that photo-quality features play a less significantrole than facial aesthetics, as expected, but they are not to be neglected, since they achieveanr 14,MOS = 0.168. Moreover we note that the high ranked traitsx 1 ,x 2 andx 4 , which representthe ratios (eye-height/face-height) and (head-width/head-height), and furthermore face shape, seeTable 6.1 are features corresponding strongly to person’s weight. This outcome brings to the forethe strong importance <strong>of</strong> low human weight for aesthetics. Furthermore it is worth noting thatTable 6.1 reveals the surprising fact among others, that non permanent traits place a pivotal rolein raising the MOS rating. Eye make-up, lipstick, glasses and hair-style are all among the top 11<strong>of</strong> the obtained ranking. These results hint the high modifiability <strong>of</strong> facial aesthetics perceptionby simple means like make-up or hair styling. The relevance <strong>of</strong> eye make-up had been previouslyobserved in [GKYG10]. Together with the different conclusions that one may draw from Table6.1, it also becomes apparent that different questions are raised, on the interconnectedness <strong>of</strong> thedifferent traits. This is addressed in Section 6.4.3. Finally we note that traits, such as x 1 , x 7 ,x 12 and x 13 directly comply with the well known babyfaceness hypothesis (see [bea11]), whichdescribes that childlike facial features in females increase attractiveness, such features include bigeyes, e.g. x 1 and a relative low location <strong>of</strong> facial elements, e.g. x 7 , x 12 and x 13 . One measureknown for increasing attractiveness, if equal to the golden ratio φ = 1.618, is x 16 .6.4.3 Interconnectedness <strong>of</strong> different traitsTo get a better understanding <strong>of</strong> the role <strong>of</strong> the different traits in raising theMOS, it is helpfulto study the inter-relationship between these traits. This is addressed in Table C.3 in the Appendix,which describes the correlation between selected traits. Due to lack <strong>of</strong> space we limit the correlationmatrix to just a group <strong>of</strong> the first six traits. Table C.3 can answer different questions such asfor example the validity <strong>of</strong> the conclusion in Table 6.1 on the importance <strong>of</strong> the make-up feature.In this case, the question arises whether it is truly the make-up that affects the MOS or whether1. For information on denotation <strong>of</strong> features and according X–values, please refer to the Appendix, Table C.2
- Page 1:
FACIAL SOFT BIOMETRICSMETHODS, APPL
- Page 5:
AcknowledgementsThis thesis would n
- Page 8:
6hair, skin and clothes. The propos
- Page 11 and 12:
97 Practical implementation of soft
- Page 13 and 14:
11Notations used in this workE : st
- Page 15 and 16:
13Chapter 1IntroductionTraditional
- Page 17 and 18:
15event of collision, which is of s
- Page 19 and 20:
17ric. In Section 6.6 we employ the
- Page 21 and 22:
19Chapter 2Soft biometrics: charact
- Page 23 and 24:
21is the fusion of soft biometrics
- Page 25 and 26: 23plied on low resolution grey scal
- Page 27 and 28: 25Chapter 3Bag of facial soft biome
- Page 29 and 30: 27In this setting we clearly assign
- Page 31 and 32: 29Table 3.1: SBSs with symmetric tr
- Page 33 and 34: 31corresponding to p(n,ρ). Towards
- Page 35 and 36: the same category (all subjects in
- Page 37 and 38: 3.5.2 Analysis of interference patt
- Page 39 and 40: an SBS by increasing ρ, then what
- Page 41 and 42: 39Table 3.4: Example for a heuristi
- Page 43 and 44: 41for a given randomly chosen authe
- Page 45 and 46: 43Chapter 4Search pruning in video
- Page 47 and 48: 45Figure 4.1: System overview.SBS m
- Page 49 and 50: 472.52rate of decay of P(τ)1.510.5
- Page 51 and 52: 49to be the probability that the al
- Page 53 and 54: 51The following lemma describes the
- Page 55 and 56: 534.5.1 Typical behavior: average g
- Page 57 and 58: 55n = 50 subjects, out of which we
- Page 59 and 60: 5710.950.9pruning Gain r(vt)0.850.8
- Page 61 and 62: 59for one person, for trait t, t =
- Page 63 and 64: 61Chapter 5Frontal-to-side person r
- Page 65 and 66: 63Figure 5.1: Frontal / gallery and
- Page 67 and 68: 6510.90.80.7Skin colorHair colorShi
- Page 69 and 70: 6710.90.80.70.6Perr0.50.40.30.20.10
- Page 71 and 72: 69Chapter 6Soft biometrics for quan
- Page 73 and 74: 71raphy considerations include [BSS
- Page 75: 73Figure 6.3: Example image of the
- Page 79 and 80: 77- Pearson’s correlation coeffic
- Page 81 and 82: 79shown to have a high impact on ou
- Page 83 and 84: 81Chapter 7Practical implementation
- Page 85 and 86: 834) Eye glasses detection: Towards
- Page 87 and 88: 857.2 Eye color as a soft biometric
- Page 89 and 90: 87Table 7.5: GMM eye color results
- Page 91 and 92: 89and office lights, daylight, flas
- Page 93 and 94: 917.5 SummaryThis chapter presented
- Page 95 and 96: 93Chapter 8User acceptance study re
- Page 97 and 98: 95Table 8.1: User experience on acc
- Page 99 and 100: 97scared of their PIN being spying.
- Page 101 and 102: 99Table 8.2: Comparison of existing
- Page 103 and 104: 101ConclusionsThis dissertation exp
- Page 105 and 106: 103Future WorkIt is becoming appare
- Page 107 and 108: 105Appendix AAppendix for Section 3
- Page 109 and 110: 107- We are now left withN −F = 2
- Page 111 and 112: 109Appendix BAppendix to Section 4B
- Page 113 and 114: 111Blue Green Brown BlackBlue 0.75
- Page 115 and 116: 113Appendix CAppendix for Section 6
- Page 117 and 118: 115Appendix DPublicationsThe featur
- Page 119 and 120: 117Bibliography[AAR04] S. Agarwal,
- Page 121 and 122: 119[FCB08] L. Franssen, J. E. Coppe
- Page 123 and 124: 121[Ley96] M. Leyton. The architect
- Page 125 and 126: 123[RN11] D. Reid and M. Nixon. Usi
- Page 127 and 128:
125[ZG09] X. Zhang and Y. Gao. Face
- Page 129:
2Rapporteurs:Prof. Dr. Abdenour HAD
- Page 132 and 133:
Biométrie faciale douce 2Les terme
- Page 134 and 135:
Biométrie faciale douce 4une perso
- Page 136 and 137:
Couleur depeauCouleur descheveuxCou
- Page 138 and 139:
Biométrie faciale douce 8Nous nous
- Page 140 and 141:
Biométrie faciale douce 103. Proba
- Page 142 and 143:
Biométrie faciale douce 12l’entr
- Page 144 and 145:
Biométrie faciale douce 14Figure 6
- Page 146 and 147:
Biométrie faciale douce 16pages 77
- Page 148 and 149:
Reviewers:Prof. Dr. Abdenour HADID,
- Page 150 and 151:
3hair, skin and clothes. The propos
- Page 152 and 153:
person in the red shirt”. Further
- Page 154 and 155:
7- Not requiring the individual’s
- Page 156 and 157:
9Probability of Collision10.90.80.7
- Page 158 and 159:
11the color FERET dataset [Fer11] w
- Page 160 and 161:
13Table 2: Table of Facial soft bio
- Page 162 and 163:
15Chapter 1PublicationsThe featured
- Page 164 and 165:
17Bibliography[ACPR10] D. Adjeroh,
- Page 166 and 167:
19[ZESH04] R. Zewail, A. Elsafi, M.