A new theoretical approach to improving face recognition in disorders of central vision: Face caricaturing

Damage to central vision, of which age-related macular degeneration (AMD) is the most common cause, leaves patients with only blurred peripheral vision. Previous approaches to improving face recognition in AMD have employed image manipulations designed to enhance early-stage visual processing (e.g., magnification, increased HSF contrast). Here, we argue that further improvement may be possible by targeting known properties of mid- and/or high-level face processing. We enhance identity-related shape information in the face by caricaturing each individual away from an average face. We simulate early- through late-stage AMD-blur by filtering spatial frequencies to mimic the amount of blurring perceived at approximately 10° through 30° into the periphery (assuming a face seen premagnified on a tablet computer).We report caricature advantages for all blur levels, for face viewpoints from front view to semiprofile, and in tasks involving perceiving differences in facial identity between pairs of people, remembering previously learned faces, and rejecting new faces as unknown. Results provide a proof of concept that caricaturing may assist in improving face recognition in AMD and other disorders of central vision

Cross-modal face identity aftereffects and their relation to priming

We tested the magnitude of the face identity aftereffect following adaptation to different modes of adaptors in four experiments. The perceptual midpoint between two morphed famous faces was measured pre- and post-adaptation. Significant aftereffects were observed for visual (faces) and non-visual adaptors (voices and names) but not non-specific semantic information (e.g., occupations). Aftereffects were also observed following imagination and adaptation to an associated person. The strongest aftereffects were found adapting to facial caricatures. These results are discussed in terms of cross-modal adaptation occurring at various loci within the face-recognition system analogous to priming

Applying psychology to forensic facial identification: perception and identification of facial composite images and facial image comparison

Eyewitness recognition is acknowledged to be prone to error but there is less understanding of difficulty in discriminating unfamiliar faces. This thesis examined the effects of face perception on identification of facial composites, and on unfamiliar face image comparison. Facial composites depict face memories by reconstructing features and configurations to form a likeness. They are generally reconstructed from an unfamiliar face memory, and will be unavoidably flawed. Identification will require perception of any accurate features, by someone who is familiar with the suspect and performance is typically poor. In typical face perception, face images are processed efficiently as complete units of information. Chapter 2 explored the possibility that holistic processing of inaccurate composite configurations will impair identification of individual features. Composites were split below the eyes and misaligned to impair holistic analysis (cf. Young, Hellawell, & Jay, 1987); identification was significantly enhanced, indicating that perceptual expertise with inaccurate configurations exerts powerful effects that can be reduced by enabling featural analysis. Facial composite recognition is difficult, which means that perception and judgement will be influence by an affective recognition bias: smiles enhance perceived familiarity, while negative expressions produce the opposite effect. In applied use, facial composites are generally produced from unpleasant memories and will convey negative expression; affective bias will, therefore, be important for facial composite recognition. Chapter 3 explored the effect of positive expression on composite identification: composite expressions were enhanced, and positive affect significantly increased identification. Affective quality rather than expression strength mediated the effect, with subtle manipulations being very effective. Facial image comparison (FIC) involves discrimination of two or more face images. Accuracy in unfamiliar face matching is typically in the region of 70%, and as discrimination is difficult, may be influenced by affective bias. Chapter 4 explored the smiling face effect in unfamiliar face matching. When multiple items were compared, positive affect did not enhance performance and false positive identification increased. With a delayed matching procedure, identification was not enhanced but in contrast to face recognition and simultaneous matching, positive affect improved rejection of foil images. Distinctive faces are easier to discriminate. Chapter 5 evaluated a systematic caricature transformation as a means to increase distinctiveness and enhance discrimination of unfamiliar faces. Identification of matching face images did not improve, but successful rejection of non-matching items was significantly enhanced. Chapter 6 used face matching to explore the basis of own race bias in face perception. Other race faces were manipulated to show own race facial variation, and own race faces to show African American facial variation. When multiple face images were matched simultaneously, the transformation impaired performance for all of the images; but when images were individually matched, the transformation improved perception of other race faces and discrimination of own race faces declined. Transformation of Japanese faces to show own race dimensions produced the same pattern of effects but failed to reach significance. The results provide support for both perceptual expertise and featural processing theories of own race bias. Results are interpreted with reference to face perception theories; implications for application and future study are discussed

Less realism : more meaning : evaluating imagery for the graphic designer

Typography\u27 as a defining term has become interchangcable with \u27graphic design\u27. and while font choice and application is seen as of paramount importance. image choice, virtually half , . of the communication design equation, is neglected in the theory and in pratice is left to the instinct of the designer. In this thesis I try to find approaches for graphic designers to understand image to the degree that they understand type. These approaches are tested through assignments for graphic design students and the results recorded and analysed. I seek to address the paradox that we are able to communicate more accurately through less accurately rendered images. I will explain how the human visual system. evolved over time by looking only upon the natural world in all its reality. can look upon a stick-figure and make an emotional and intellectual connection. I examine the design implications of this strange faculty of the visual system. Gombrich. Arnheim and others have explored realism in, and applied psychology to, art in order to become better art historians. I explore the implications in the more pragmatic. economically imperative field of design of moving away from realism in the visual aspects of communication

Caricature generator

Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Bibliography: leaves 111-116.The human face is a highly significant visual display which we are able to remember and recognize easily despite the fact that we are exposed to thousands of faces which may be metrically very similar. caricature is a graphical coding of facial features which seeks to be more like the face than the face itself: selected information is exaggerated, noise is reduced, and the processes involved in recognition are exploited. After studying the methods of caricaturists, examining perceptual phenomena regarding individuating features, and surveying automatic and man-machine systems which represent and manipulate the face, some heuristics for caricature are defined . An algorithm is implemented to amplify the nuance of a human face in a computer- generated caricature. This is done by comparing the face to a norm and then distorting the face even further away from that norm . Issues of style, context and animation are discussed. The applications of the caricature generator in the areas of teleconferencing, games, and interactive graphic interfaces are explored.by Susan Elise Brennan.M.S.V.S

The organization of conspecific face space in nonhuman primates

Humans and chimpanzees demonstrate numerous cognitive specializations for processing faces, but comparative studies with monkeys suggest that these may be the result of recent evolutionary adaptations. The present study utilized the novel approach of face space, a powerful theoretical framework used to understand the representation of face identity in humans, to further explore species differences in face processing. According to the theory, faces are represented by vectors in a multidimensional space, the centre of which is defined by an average face. Each dimension codes features important for describing a face's identity, and vector length codes the feature's distinctiveness. Chimpanzees and rhesus monkeys discriminated male and female conspecifics' faces, rated by humans for their distinctiveness, using a computerized task. Multidimensional scaling analyses showed that the organization of face space was similar between humans and chimpanzees. Distinctive faces had the longest vectors and were the easiest for chimpanzees to discriminate. In contrast, distinctiveness did not correlate with the performance of rhesus monkeys. The feature dimensions for each species' face space were visualized and described using morphing techniques. These results confirm species differences in the perceptual representation of conspecific faces, which are discussed within an evolutionary framework

Face-space: A unifying concept in face recognition research

The concept of a multidimensional psychological space, in which faces can be represented according to their perceived properties, is fundamental to the modern theorist in face processing. Yet the idea was not clearly expressed until 1991. The background that led to the development of face-space is explained, and its continuing influence on theories of face processing is discussed. Research that has explored the properties of the face-space and sought to understand caricature, including facial adaptation paradigms, is reviewed. Face-space as a theoretical framework for understanding the effect of ethnicity and the development of face recognition is evaluated. Finally, two applications of face-space in the forensic setting are discussed. From initially being presented as a model to explain distinctiveness, inversion, and the effect of ethnicity, face-space has become a central pillar in many aspects of face processing. It is currently being developed to help us understand adaptation effects with faces. While being in principle a simple concept, face-space has shaped, and continues to shape, our understanding of face perception

Perception and recognition of computer-enhanced facial attributes and abstracted prototypes

The influence of the human facial image was surveyed and the nature of its many interpretations were examined. The role of distinctiveness was considered particularly relevant as it accounted for many of the impressions of character and identity ascribed to individuals. The notion of structural differences with respect to some selective essence of normality is especially important as it allows a wide range of complex facial types to be considered and understood in an objective manner. A software tool was developed which permitted the manipulation of facial images. Quantitative distortions of digital images were examined using perceptual and recognition memory paradigms. Seven experiments investigated the role of distinctiveness in memory for faces using synthesised caricatures. The results showed that caricatures, both photographic and line-drawing, improved recognition speed and accuracy, indicating that both veridical and distinctiveness information are coded for familiar faces in long-term memory. The impact of feature metrics on perceptual estimates of facial age was examined using 'age-caricatured' images and were found to be in relative accordance with the 'intended' computed age. Further modifying the semantics permitted the differences between individual faces to be visualised in terms of facial structure and skin texture patterns. Transformations of identity between two, or more, faces established the necessary matrices which can offer an understanding of facial expression in a categorical manner and the inherent interactions. A procedural extension allowed generation of composite images in which all features are perfectly aligned. Prototypical facial types specified in this manner enabled high-level manipulations to be made of gender and attractiveness; two experiments corroborated previously speculative material and thus gave credence to the prototype model. In summary, psychological assessment of computer-manipulated facial images demonstrated the validity of the objective techniques and highlighted particular parameters which contribute to our perception and recognition of the individual and of underlying facial types