Face Recognition Based on Manifold Learning and SVM Classification of 2D and 3D Geodesic Curves

2011 ◽  
pp. 62-81 ◽  
Author(s):  
Stefano Berretti ◽  
Alberto Del Bimbo ◽  
Pietro Pala ◽  
Francisco Josè Silva Mata
Keyword(s):  
Face Recognition ◽  
Manifold Learning ◽  
Three Dimensional ◽  
Still Images ◽  
3D Face ◽  
Hybrid Approaches ◽  
Manifold Embedding ◽  
The Difference ◽  
The One ◽  
2D And 3D

This chapter has a twofold objective. On the one hand, an original approach based on the computation of radial geodesic distances (RGD) is proposed to represent two-dimensional (2D) face images and three-dimensional (3D) face models for the purpose of face recognition. In 3D, the RGD of a generic point of a 3D face surface is computed as the length of the particular geodesic that connects the point with a reference point along a radial direction. In 2D, the RGD of a face image pixel with respect to a reference pixel accounts for the difference of gray level intensities of the two pixels and the Euclidean distance between them. The main contribution of this solution is to permit direct comparison between representations extracted from 2D and 3D facial data, thus opening the way to hybrid approaches for face recognition capable to combine and exploit advantages of different media so as to overcome limitations of traditional solutions based on 2D still images. On the other hand, face representations based on RGDs are used for the purpose of face identification by using them in an operative framework that exploits state of the art techniques for manifold embedding and machine learning. Due to the high dimensionality of face representations based on RGD, embedding into lower-dimensional spaces using manifold learning is applied before classification. Support Vector Machines (SVMs) are used to perform face recognition using 2D- and 3D-RGDs. This shows a general work flow that is not limited to face recognition applications, but can be used in many different contexts of recognition and retrieval. Experimental results are reported for 3D-3D and 2D-3D face recognition using the proposed approach.

scholarly journals Do 3D Face Images Capture Cues of Strength, Weight, and Height Better than 2D Face Images do?

2021 ◽  
Vol 7 (3) ◽  
pp. 209-219
Author(s):  
Iris J Holzleitner ◽  
Alex L Jones ◽  
Kieran J O’Shea ◽  
Rachel Cassar ◽  
Vanessa Fasolt ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Physical Characteristics ◽  
Two Dimensional ◽  
3D Images ◽  
3D Face ◽  
Face Images ◽  
Similar Accuracy ◽  
2D And 3D ◽  
2D Images ◽  
Better Than

Abstract Objectives A large literature exists investigating the extent to which physical characteristics (e.g., strength, weight, and height) can be accurately assessed from face images. While most of these studies have employed two-dimensional (2D) face images as stimuli, some recent studies have used three-dimensional (3D) face images because they may contain cues not visible in 2D face images. As equipment required for 3D face images is considerably more expensive than that required for 2D face images, we here investigated how perceptual ratings of physical characteristics from 2D and 3D face images compare. Methods We tested whether 3D face images capture cues of strength, weight, and height better than 2D face images do by directly comparing the accuracy of strength, weight, and height ratings of 182 2D and 3D face images taken simultaneously. Strength, height and weight were rated by 66, 59 and 52 raters respectively, who viewed both 2D and 3D images. Results In line with previous studies, we found that weight and height can be judged somewhat accurately from faces; contrary to previous research, we found that people were relatively inaccurate at assessing strength. We found no evidence that physical characteristics could be judged more accurately from 3D than 2D images. Conclusion Our results suggest physical characteristics are perceived with similar accuracy from 2D and 3D face images. They also suggest that the substantial costs associated with collecting 3D face scans may not be justified for research on the accuracy of facial judgments of physical characteristics.

scholarly journals A comparison of animated versus static images in an instructional multimedia presentation

2016 ◽  
Vol 40 (2) ◽  
pp. 201-205 ◽  
Author(s):  
C. J. Daly ◽  
J. M. Bulloch ◽  
M. Ma ◽  
D. Aidulis
Keyword(s):  
Student Satisfaction ◽  
Undergraduate Students ◽  
Three Dimensional ◽  
The Other ◽  
Multimedia Presentation ◽  
Still Images ◽  
Significant Difference ◽  
Essay Question ◽  
The Difference ◽  
Video Compositing

Sophisticated three-dimensional animation and video compositing software enables the creation of complex multimedia instructional movies. However, if the design of such presentations does not take account of cognitive load and multimedia theories, then their effectiveness as learning aids will be compromised. We investigated the use of animated images versus still images by creating two versions of a 4-min multimedia presentation on vascular neuroeffector transmission. One version comprised narration and animations, whereas the other animation comprised narration and still images. Fifty-four undergraduate students from level 3 pharmacology and physiology undergraduate degrees participated. Half of the students watched the full animation, and the other half watched the stills only. Students watched the presentation once and then answered a short essay question. Answers were coded and marked blind. The “animation” group scored 3.7 (SE: 0.4; out of 11), whereas the “stills” group scored 3.2 (SE: 0.5). The difference was not statistically significant. Further analysis of bonus marks, awarded for appropriate terminology use, detected a significant difference in one class (pharmacology) who scored 0.6 (SE: 0.2) versus 0.1 (SE: 0.1) for the animation versus stills group, respectively ( P = 0.04). However, when combined with the physiology group, the significance disappeared. Feedback from students was extremely positive and identified four main themes of interest. In conclusion, while increasing student satisfaction, we do not find strong evidence in favor of animated images over still images in this particular format. We also discuss the study design and offer suggestions for further investigations of this type.

The role of the geoid in one-, two-, and three-dimensional network adjustments

CISM journal ◽  
1990 ◽  
Vol 44 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Michael G. Sideris
Keyword(s):  
Three Dimensional ◽  
One Dimensional ◽  
Control Networks ◽  
Deflections Of The Vertical ◽  
Dimensional Network ◽  
3D Network ◽  
Computational Procedures ◽  
The One ◽  
2D And 3D

The geoid and its horizontal derivatives, the deflections of the vertical, play an important role in the adjustment of geodetic networks. In the one-dimensional (1D) case, represented typically by networks of orthometric heights, the geoid provides the reference surface for the measurements. In the two-dimensional (2D) adjustment of horizontal control networks, the geoidal undulations N and deflections of the vertical ξ, η are needed for the reduction of the measured quantities onto the reference ellipsoid. In the three-dimensional (3D) adjustment, N and ξ, η are basically required to relate geodetic and astronomic quantities. The paper presents the major gravimetric methods currently used for predicting ξ, η and N, and briefly intercompares them in terms of accuracy, efficiency, and data required. The effects of N, ξ, η on various quantities used in the ID, 2D, and 3D network adjustments are described explicitly for each case and formulas are given for the errors introduced by either neglecting or using erroneous N, ξ, η in the computational procedures.

ENERGY SPECTRUM OF DISTURBANCE AT TURBULENT TRANSITION VIA ENERGY GRADIENT METHOD

2012 ◽  
Vol 19 ◽  
pp. 293-303 ◽  
Author(s):  
HUA-SHU DOU ◽  
BOO CHEONG KHOO
Keyword(s):  
Energy Spectrum ◽  
Flow Instability ◽  
Three Dimensional ◽  
Wave Number ◽  
Gradient Theory ◽  
Turbulent Transition ◽  
Energy Gradient Theory ◽  
Energy Gradient ◽  
The Difference ◽  
2D And 3D

The energy gradient theory for flow instability and turbulent transition was proposed in our previous work. The theoretical result obtained accords well with some experimental data for pipe and channel flows in the literature. In the present study, the energy gradient theory is extended to examine the effect of disturbance frequency on turbulent transition. Then, the energy spectrum of disturbance at the turbulent transition is obtained, which scales with the wave number by an exponent of –2. This scaling is near to the K41 law of –5/3 for the full developed isentropic homogenous turbulence. The difference for the two energy spectra may be due to the intermittency of turbulence at the transition state. The intermittence causes the distribution of the energy spectrum to take on a steeper gradient (tending to –2 from –5/3). Finally, the flow instability leading to turbulent transition can be classified as two-dimensional (2D) or three-dimensional (3D) in terms of the wave number and the Re. It is found that there is an optimum wave number which separates the 2D and 3D transitions and at which the disturbance energy at transition is minimum.

The Dialectics of Creation and the Projective Structure of Space

2021 ◽  
Vol 13 (1-2) ◽  
pp. 357-376
Author(s):  
Marat Gorodezky ◽  
Keyword(s):  
Three Dimensional ◽  
General Idea ◽  
Projective Structure ◽  
Single Plane ◽  
Logical Connection ◽  
The World ◽  
Usual Scheme ◽  
The Difference ◽  
The One ◽  
Dimensional Object

The article considers creationism as a historically relevant principle in the scientific and philosophic aspects denoting the ontological structure of the world. Outside of the religious interpretation, the author speaks of the dialectics of creation, which is revealed as an implicative connection of the one and nothing. Logical inversion (logical turn), acting from within this implicative connection, is postulated as the principle of a fundamental negation, which, according to the author, forms the true and dramatic essence of the world as a creation. The author distances himself from the widespread discussion between evolutionism and scientific creationism, stating that it does not correspond to the very subject of creationism, understood as the implication of a real from nothing. The author focuses on considering ‘nothing’ as a purely dialectical / metaphysical principle and relies partly on the Hegel’s dialectic of ‘being’ and ‘nothing’, and partly on the neoplatonic concept of the one. Rejecting the medieval interpretation of the temporal beginning and the Hegel’s identity, he deduces a scheme of the logical connection between the one and the difference, which postulates the inversion (turnover) forming the creation - the one and the difference disjunctively change places, the one becomes the real, and the difference out of the one becomes nothing. It is argued that this postulate, in particular, refutes the thesis about the ‘fall into sin’. In the second part of the article, a spatial-phenomenological hypothesis is presented: the author provides a description of the space as a geometrical-semantic plane (projective structure). This hypothesis follows from the phenomenological problem of the duality of a geometric object, which results in the problem of ontological transition between a point and a line (in the aporia of the Eleats) and the related problem of spatial congruence / parallelism. According to the author, the potential for solving these not essentially mathematical, but metaphysical questions is the projective geometry, in which parallel lines intersect at ‘point at infinity’, and space is complemented by the ‘plane at infinity’. The essence of the solution consists, firstly, in the assumption of the single plane, which underlies the transition, and secondly, in the description of the perceived world as a result of a specific turn over and closure of this plane, forming the projective structure. The key in this part is the demonstration of the surface of a three-dimensional object as a phenomenon of perceptual-semantic unfolding, which can be imagined as an action of consciousness, consistently reducing the usual scheme. An important aspect of considering the projective structure is the correlation with ‘the Plane’ by G. Deleuze. The general idea of the article is that the dialectical scheme of creation and the projective structure of the space coincide: the logical inversion (logical turn), acting in connection of the one and nothing, and projective structural turnover – are the same things.

scholarly journals ROBUST REPRESENTATION OF 3D FACES FOR RECOGNITION

2006 ◽  
Vol 20 (08) ◽  
pp. 1159-1186 ◽  
Author(s):  
A. BELÉN MORENO ◽  
ÁNGEL SÁNCHEZ ◽  
ENRIQUE FRÍAS-MARTÍNEZ
Keyword(s):  
Face Recognition ◽  
Facial Expressions ◽  
Facial Recognition ◽  
Recognition Rate ◽  
Relevant Information ◽  
Large Set ◽  
Discrimination Power ◽  
3D Face ◽  
The Face ◽  
The Difference

Automatic face recognition is becoming increasingly important due to the security applications derived from it. Although the facial recognition problem has focused on 2D images, recently, due to the proliferation of 3D scanning hardware, 3D face recognition has become a feasible application. This 3D approach does not need any color information. In this way, it has the following main advantages in comparison to more traditional 2D approaches: (1) being robust under lighting variations and (2) providing more relevant information. In this paper we present a new 3D facial model based on the curvature properties of the surface. Our system is able to detect the subset of the characteristics of the face with higher discrimination power from a large set. The robustness of the model is tested by comparing recognition rates using both controlled and noncontrolled environments regarding facial expressions and facial rotations. The difference between the recognition rates of the two environments of only 5% proves that the model has a high degree of robustness against pose and facial expressions. We consider that this robustness is enough to implement facial recognition applications, which can achieve up to 91% correct recognition rate. A publish 3D face database containing face rotations and expressions has been created to achieve the recognition experiments.

Combined Effects of 2D and 3D Inhomogeneities on the Dynamic Susceptibility of Superlattices

2010 ◽  
Vol 168-169 ◽  
pp. 97-100
Author(s):  
V.A. Ignatchenko ◽  
D.S. Tsikalov
Keyword(s):  
Density Of States ◽  
Three Dimensional ◽  
Wave Number ◽  
Dynamic Susceptibility ◽  
Combined Effects ◽  
Two Dimensional ◽  
Simultaneous Presence ◽  
One Dimensional ◽  
The One ◽  
2D And 3D

The dynamic susceptibility and the one-dimensional density of states (DOS) of an initially sinusoidal superlattice (SL) with simultaneous presence of two-dimensional (2D) phase inhomogeneities that simulate the deformations of the interfaces between the SL’s layers and three-dimensional (3D) amplitude inhomogeneities of the layer material of the SL were investigated. An analytical expression for the averaged Green’s function of the sinusoidal SL with 2D phase inhomogeneities was obtained in the Bourret approximation. It was shown that the effect of increasing asymmetry of heights of the dynamic susceptibility peaks at the edge of the Brillouin zone of the SL, which was found in [6] at increasing the rms fluctuations of 2D inhomogeneities, also takes place at increasing the correlation wave number of such inhomogeneities. It was also shown that the increase of the rms fluctuations of 3D amplitude inhomogeneities in the superlattice with 2D phase inhomogeneities leads to the suppression of the asymmetry effect and to the decrease of the depth of the DOS gap.

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