attention. Lacmann (1950) devoted a short section of his book to ihe 
subject, in whieh he showed an infrared image contrasted with a 
conventional photograph of a human forearm. Equipment for infrared 
imagery is‘ HOW widely available (Barnes 1963), but 
stereophotogrammetric applications await further study of the spatial 
fidelity. 
The improved resolution of xeroradiography over that of 
conventional x-rays has been used recently for stereoscopic 
representation (Boag, Stacey and Davis 1971) and a small pilot project 
has been undertaken to explore the stereometric capabilities (Herron and 
Cuzzi, 1971). Like ultrasonic, infrared and xeroradiography, there are 
various other imaging processes at a relatively undeveloped stage of 
stereophotogrammetric use, including ultraviolet, radionuclide imagery 
(Maynard and Engler 1969), and neutron radiography (Robinson and 
Porter 1969) among others. Wong (1968, 1971) has investigated the 
geometric cgjibration of television systems for stereophotogrammetric 
purposes and it seems inevitable that T.V. imagery will have important 
implications for biostereometrics in the future. 
5.3 Holographic Interferometry Moiré Fringe and Lichtschnitteverfahren 
A variety of optical devices can be used to project contour lines on 
a body or body part which can then be photographed. ln a recent 
article, Varner (1971) discussed the advantages and disadvantages of four 
such techniques: (]) multiple-frequency holographic contouring, (2) 
multiple-index holographic contouring, which he had previously used on 
teeth (Chmielewski and Varner, 1969), (3) multiple-source contouring, 
and (4) moiré fringe contouring. He concluded that "overall, the moiré 
fringe method seems to have the most to offer: it is simple, real-time, 
and it has a useful, continuous range of sensitivity." His second 
preference was the multiple-source technique, with the two holographic 
techniques considered least advantageous. 
Moiré fringe contouring, which does not require coherent light, but 
only a point source and a linear amplitude grating, has been used by 
Takasaki (1970) to contour the living subject. On comparing his moiré 
fringe technique with the moiré gauging method of Brooks and 
Hefflinger (1969) in which a regularly spaced laser interference pattern 
is projected on the object, he concluded that both methods seem to 
have their merits and demerits. Zivi and Humberstone (1970), 
co-workers of Brooks and Hefflinger at TRW, Inc. in California, have 
obtained holographic interferograms of chest motion in normals and a 
subject with left pneumonectomy. 
Tolansky (1968) edited a very readable survey of interferometry at 
the microscopic level which includes an introduction to the basic 
concepts of topographic analysis in general.