Three-Dimensional Body Shape Measurement from Single Photographs

There is an extensive number of applications of human body shape measurement, for medical, apparel and other purposes, and there is a variety of means of undertaking this task, with a range of complexities, accuracies, and costs.This paper discusses one method, known as shape-from-shading, which emphasises simplicity and low cost for determining body shape.Measurement is based on a single photograph of the body area of interest, provided that the area is illuminated by a suitable point light source, typically provided by a camera's flash.The method requires neither specialised equipment nor special operator skills, so the procedure is cheap, portable, easy to use, not inconvenient for the patient, but still able to provide the three-dimensional information about a patient's body which is appropriate for various purposes.The process is not simply a matter of presenting a photograph's grey-scales in three-dimensions, but it involves computing a numerical three-dimensional object shape, so that graphical views can be created, but, more importantly, measurements can be taken from the surface model which the method produces.The theory is not trivial, which creates severe practical limitations in many measurement cases, but many problems can often be avoided in many human body surface topography studies, because human skin surface is often evenly coloured, not especially shiny, and generally free from major colour changes.As well, the body shapes of interest can largely be assumed to be smooth, not too convoluted, and free from discontinuities and steep gradients, and this suits the photographic measurement method.It is foreseeable that the technique could be used for a variety of purposes such as providing breast volumes for apparel fitting, aiding scoliosis surveillance, but primarily by helping to create body moulds for radiation positioning and for prosthetic devices.This paper provides a non-technical outline of the features of the technique, to present this method of measurement and its characteristics, with examples of successful measurement.