Philip J Benson

Perception and recognition of photographic quality facial caricatures: Implications for the recognition of natural images

Abstract The perception and recognition of photographic images of famous faces was compared with the same images transformed to produce caricatures of different degrees of exaggeration. Following Brennan (1982; 1985). caricatures were produced by first comparing the position of facial features in a frame-grabbed image with the average position for a series of faces; deviations from the average were then accentuated by a constant fraction (16, 32 or 48%). Photographic quality caricatures for seven famous faces were generated by distorting regions of the original images in accordance with the change in feature positions. Images reducing the distinctiveness of faces (anticaricatures) were produced by decreasing deviations from the norm. In Experiment 1, perceptual ratings of the degree to which images resembled the individuals depicted was found to vary with the degree of caricaturing (−32, −16, 0, +16, +32%). Interpolation from the data indicated that the best likeness occurred for images with a small degre...

Extracting Prototypical Facial Images from Exemplars

A computer graphic method for extracting a natural image of an individuals facial prototype, or average appearance, from a number of different images of that individual is presented. The process improves upon previous photographic and computational techniques. Synthesis of a persons average expression and pose from a sample of images is derived in an automatic and quantitative way. Possible uses of composite faces produced in this manner in psychological investigations of facial qualities (eg attractiveness) and in applied areas such as telecommunication are pointed out.

Synthesizing continuous-tone caricatures

Abstract A series of tools has been developed to synthesize full colour photographic quality facial caricatures. Real faces, photographs or single-frame video films are frame-grabbed and the position of (186) key points around external and internal features are interactively defined. Following procedures of Brennan 7,8 the 2D Cartesian coordinates of each feature point are compared with those of an average for many faces; differences in positions are exaggerated (to produce caricature data sets) or reduced (giving ‘anticaricature’ data sets). Line-drawing representations of faces and their caricatures are formed by linking appropriate feature points. To produce continuous-tone caricatures, the original and caricature images are resolved into (340) adjacent triangular tessellations. Rendering of the final image is accomplished by mapping the pixel values (grey-scale or colour) from each source triangle in the original image to the corresponding triangle in the caricature image. The caricatures not only provide amusement, but can be used as stimuli in psychological investigations into the representation of faces in human memory.