Illumination-Induced Apparent Shift in Orientation of Human Heads

Perception ◽  
1998 ◽  
Vol 27 (6) ◽  
pp. 671-680 ◽  
Author(s):  
Nikolaus F Troje ◽  
Ulrike Siebeck
Keyword(s):  
Light Source ◽  
Human Face ◽  
Visual Texture ◽  
Orientation Judgment ◽  
Profile Line ◽  
The Face ◽  
Left And Right ◽  
The Mean ◽  
Apparent Shift ◽  
Apparent Orientation

Changing the position of a light source illuminating a human face induces an apparent shift of the perceived orientation of that face. The direction of this apparent shift is opposite to the shift of the light source. We demonstrated the illumination-induced apparent orientation shift (IAOS), quantified it in terms of the physical orientation shift needed to compensate for it, and evaluated the results in the context of possible mechanisms underlying orientation judgment. Results indicate that IAOS depends not only on the angle between the two light source positions, but also on the mean orientation of the face. Availability of cues coded in the visual texture of the face did not affect IAOS. The most effective cue was the location of the visible outline of the face. IAOS seems to be due to a shift of this outline when shadowed areas on the face merge with the black background. We conclude that an important mechanism for orientation judgment is based on a comparison of visible parts left and right of the profile line.

scholarly journals The specificity of interpersonal perception in terms of presentation of the image of a whole face and a «split face» on the example of perception of pictorial portraits

2015 ◽  
Vol 8 (4) ◽  
pp. 120-133 ◽  
Author(s):  
E.A. Lupenko
Keyword(s):  
Experimental Data ◽  
Interpersonal Perception ◽  
Stimulus Material ◽  
Psychological Characteristics ◽  
Human Face ◽  
The Face ◽  
Left And Right ◽  
The Right ◽  
Split Face

The article presents a study of the specificity of perception of expression of the whole and fragmented (divided into left and right half) face made on the example of the perception of pictorial portraits. The data obtained in the study are fully consistent with previously obtained results of the similar study of perception of facsimiles (Artemtseva, 2003, Barabanschikov, Boldyrev, 2007; Barabanschikov, Zhegallo, 2013). The right and the left side of the face and the image of a whole face have their own expressive potential, which is reflected in the use by observer of different individual psychological characteristics in their description. The expression of a whole face often has a contradictory character with overly intensified emotions and is not a simple sum of the characteristics that are used in the description of the right and left halves of the face. Thus, perception of expression of a whole face and of a “split face” brings up several different patterns of personality. The similarity of the experimental data, obtained at different stimulus material (portraits and images), speaks about the invariance of perception of human face, regardless of the method of its representation.

Judging the Orientation of Human Faces: Effects Induced by Varying the Illumination

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 357-357
Author(s):  
U Siebeck ◽  
N F Troje
Keyword(s):  
Symmetry Plane ◽  
Local Surface ◽  
Black Background ◽  
The Face ◽  
Left And Right ◽  
Average Orientation ◽  
Human Faces ◽  
Apparent Orientation

How do people estimate the orientation of other people's faces? We observed that two images of a face seen from the same orientation, but illuminated from different angles, appeared to have different orientations. The first experiment was designed to document and quantify this phenomenon with respect to the average orientation of the face. The images were rendered on a black background that made it impossible to discriminate the shadowed facial parts from the background. We determined the physical orientation shift necessary to compensate for the illumination-induced effect. Results showed that the measured illumination-induced apparent orientaion shift (IAOS) correlates positively with the average orientation of the face and reaches values of up to 9°. This correlation implies that the mechanism is not based on local surface attitude judgements. We propose a model in which the symmetry plane of the face is detected, and then a comparison is made between the visible parts on both sides of this plane. The effect of the shadow occluding parts of the faces would then be responsible for the apparent orientation shift. To test this hypothesis we repeated the first experiment using a background colour that allowed subjects to perceive the true outline of the faces. We found that the IAOS was reduced to values of less than 2° and no longer depended on the average orientation of the faces. The results imply that orientation may be judged by comparing the size of the visible parts of the left and right halves of the face.

Conventions and temporal differences in painted faces: A study of posture and color distribution

2020 ◽  
Vol 2020 (11) ◽  
pp. 267-1-267-8
Author(s):  
Mitchell J.P. van Zuijlen ◽  
Sylvia C. Pont ◽  
Maarten W.A. Wijntjes
Keyword(s):  
Scientific Community ◽  
Human Face ◽  
Art Galleries ◽  
Art Collections ◽  
Color Distribution ◽  
Scientific Domain ◽  
The Face ◽  
And Gender ◽  
Changes Over Time ◽  
Over Time

The human face is a popular motif in art and depictions of faces can be found throughout history in nearly every culture. Artists have mastered the depiction of faces after employing careful experimentation using the relatively limited means of paints and oils. Many of the results of these experimentations are now available to the scientific domain due to the digitization of large art collections. In this paper we study the depiction of the face throughout history. We used an automated facial detection network to detect a set of 11,659 faces in 15,534 predominately western artworks, from 6 international, digitized art galleries. We analyzed the pose and color of these faces and related those to changes over time and gender differences. We find a number of previously known conventions, such as the convention of depicting the left cheek for females and vice versa for males, as well as unknown conventions, such as the convention of females to be depicted looking slightly down. Our set of faces will be released to the scientific community for further study.

Real Time Person Recognition and Attendance Marking Using Holistic Based Approach

2017 ◽  
Vol 7 (7) ◽  
pp. 302
Author(s):  
Reshma P ◽  
Muneer VK ◽  
Muhammed Ilyas P
Keyword(s):  
Face Recognition ◽  
Real Time ◽  
High Accuracy ◽  
Efficient Technique ◽  
Human Face ◽  
Traditional Methods ◽  
Person Recognition ◽  
The Face

Face recognition is a challenging task for the researches. It is very useful for personal verification and recognition and also it is very difficult to implement due to all different situation that a human face can be found. This system makes use of the face recognition approach for the computerized attendance marking of students or employees in the room environment without lectures intervention or the employee. This system is very efficient and requires very less maintenance compared to the traditional methods. Among existing methods PCA is the most efficient technique. In this project Holistic based approach is adapted. The system is implemented using MATLAB and provides high accuracy.

Utilising Indigenous Knowledge or Crime against Humanity?: A Critical Engagement with the Debate Generated by Alick Macheso’s Use of Manhood to Treat Nhova (Sunken Fontanelle)

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Charles Tembo ◽  
Allan Maganga ◽  
Peterson Dewah
Keyword(s):  
Ethical Issues ◽  
General Tendency ◽  
Ethical Values ◽  
Ethical Considerations ◽  
Lower Back ◽  
African Ethics ◽  
Cultural Grounding ◽  
The Face ◽  
Left And Right ◽  
Points Of View

 This article presents various points of view regarding the treatment of sunken fontanelle by various communities as ignited by the controversial practice of kutara(a practice that involves the father of a child sliding his penis from the lower part of the left and right cheeks to the top of the head, as well as from the lower part of the face to the top of the head, and from the lower back part of the head to the top). The story of Alick Macheso’s use of his manhood to treat nhova (sunken fontanelle) opened a Pandora’s box. The story not only attracted the attention of critics from diverse cultural and ethical backgrounds, but revealed multi-ethnic positions. That is, reactions were steeped in a multiplicity of intellectual, religious and even cultural grounding. Reactions ranged from accusations of backwardness and absurdity, through to medical and Christian orientations toward the treatment of nhova. The overarching idea is that there is a general tendency to dismiss the age-old practice of kutara,coupled with an uncritical celebration of certain positions. The debate that ensued following publication of the story seemed to revolve around ethical considerations. The school of thought that dismisses kutara with disdain regards it as unethical and unimaginable in the present-day world—it is redolent with insinuations of absurdity on the part of those that live and celebrate it. We contend that the raging debate that followed the publication of the story can best be conceptualised within the context of African ethics. We note that kutara has relevance to the spirituality, ethical values, privacy, and protection of children’s rights, among other ethical issues. It is hoped that the article will stir further debate and encourage more research among information practitioners, scholars and researchers into the ethical issues surrounding the treatment of sunken fontanelle in various African communities. It argues for an Afrocentric conceptualisation of phenomena in order to contribute to debates on the renaissance of African cultures, and stresses that it is imperative to harness the life-furthering age-old traditions in African ontological existence.

The Difference in Facial Movement Between the Medial and the Lateral Midface: A 3D Skin Surface Vector Analysis

2021 ◽  
Author(s):  
David L Freytag ◽  
Michael G Alfertshofer ◽  
Konstantin Frank ◽  
Dmitry V Melnikov ◽  
Nicholas Moellhoff ◽  
...  
Keyword(s):  
3D Imaging ◽  
Functional Anatomy ◽  
Skin Surface ◽  
Facial Movements ◽  
Anatomic Location ◽  
Objective Evidence ◽  
The Face ◽  
Functional Boundary ◽  
The Mean ◽  
The Difference

Abstract Background Our understanding of the functional anatomy of the face is constantly improving. To date, it is unclear whether the anatomic location of the line of ligaments has any functional importance during normal facial movements such as smiling. Objectives It is the objective of the present study to identify differences in facial movements between the medial and lateral midface by means of skin vector displacement analyses derived from 3D imaging and to further ascertain whether the line of ligaments has both a structural and functional significance in these movements. Methods The study sample consisted of 21 healthy volunteers (9 females & 12 males) of Caucasian ethnic background with a mean age of 30.6 (8.3) years and a mean BMI of 22.57 (2.5) kg/m 2. 3D images of the volunteers’ faces in repose and during smiling (Duchenne type) were taken. 3D imaging-based skin vector displacement analyses were conducted. Results The mean horizontal skin displacement was 0.08 (2.0) mm in the medial midface (lateral movement) and was -0.08 (1.96) mm in the lateral midface (medial movement) (p = 0.711). The mean vertical skin displacement (cranial movement of skin toward the forehead/temple) was 6.68 (2.4) mm in the medial midface whereas it was 5.20 (2.07) mm in the lateral midface (p = 0.003). Conclusions The results of this study provide objective evidence for an antagonistic skin movement between the medial and the lateral midface. The functional boundary identified by 3D imaging corresponds to the anatomic location of the line of ligaments.

scholarly journals Edemas of the face and lymphoscintigraphic examination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pierre Bourgeois ◽  
E. Peters ◽  
A. Van Mieghem ◽  
A. Vrancken ◽  
G. Giacalone ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Lymph Node ◽  
Cervical Lymph Node ◽  
Cervical Vertebra ◽  
Lymphatic Drainage ◽  
The Face ◽  
Facial Edema ◽  
Post Traumatic ◽  
Left And Right ◽  
Lymphatic Pathways

AbstractFacial edemas not secondary to surgery and/or radiotherapy for head and neck cancer are relatively uncommon. Our aim is to report a retrospective analysis of the lymphoscintigraphic and SPECT-CT investigations obtained in patients with such facial edema. Retrospective review of exams (planar imagings in all and with SPECT-CT in 5) obtained after the subcutaneous injection of 99mTc HSA Nanosized colloids between the eyebrows in five men and seven women. Four main lymphatic pathways were identified on sequential planar imagings: para-nasal left and right and supra- ocular left and right. For eleven patients, the absence of visualization of lymphatic drainage and/or their delayed appearance correlated well with the localisation of the edematous areas. In two patients with post-traumatic and post- surgical edemas, SPECT-CT showed one deep left sided cervical lymph node (LN) in front of the first cervical vertebra. This lymphoscintigraphic approach represents a simple and valuable way to assess the lymphatic drainage pathways of the face and to establish the diagnosis of facial lymphedema.

Studies on the storage of potatoes. III. The composition of the atmosphere in a potato clamp

1950 ◽  
Vol 40 (3) ◽  
pp. 227-232 ◽  
Author(s):  
E. M. Crook ◽  
D. J. Watson
Keyword(s):  
Multiple Regression ◽  
Wind Velocity ◽  
Practical Importance ◽  
Oxygen Depletion ◽  
Unsaturated Compounds ◽  
The Face ◽  
Flow Through ◽  
The Mean ◽  
Oxygen Concentrations

The CO2 concentration in the atmosphere of a potato clamp varied between 0·06 and 0·86%. The sum of CO2 and oxygen concentrations remained approximately constant at 21%. The CO2 concentration increased with time from December to April. This was attributed to increase in the rate of respiration of the potatoes caused by rise of temperature. Wind blowing in the direction normal to the face of the clamp reduced the COa concentration, presumably by causing external air to flow through the clamp coverings. A multiple regression of CO2 concentration on temperature of the potatoes at the time of sampling, and on the mean component of wind velocity normal to the clamp face estimated over a period of 3 hr. before the time of sampling, accounted for 64% of the variance between sampling occasions.Unsaturated compounds were detected in the clamp atmosphere by absorption in bromine; the concentration of these, expressed as ethylene, varied between 0·004 and 0·025%.The magnitude of CO2 accumulation and oxygen depletion in the clamp atmosphere was too small to produce effects of practical importance on the storage behaviour of the potatoes. If the unsaturated compounds were ethylene, the concentration present was sufficient to cause appreciable retardation of sprouting.

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