[Imager Theses and Major Essays] [Imager] [UBC Computer Science]


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Katrina M. Archer

Craniofacial Reconstruction Using Hierarchical B-Spline Interpolation


Degree:  M.A.Sc.
Type:  thesis
Year:  1997
Supervisors: Rabab Ward and David R. Forsey
Electronic:  [PDF], 810249 bytes
Hardcopy: 113 pages

Abstract

Craniofacial forensic reconstruction is often the only means of determining a deceased individual's appearance. Current manual methods of estimating the appearance of the individual from his or her skull are extremely expensive and time-consuming. Normally a single facia estimate is produced and publicized. As a result, the success rate for identification resulting from facial reconstruction is on the order of only 50%. A software tool that produces multiple three-dimensional likenesses that more completely cover the range of likely appearances due to factors such as body fat content, and nose and lip appearance would improve this success rate. The application should closely simulate the artist's technique of generating a base facial shape with rough details that are later refined. The prototype generates a generic hierarchical B-spline surface around a 3D scan of the skull. Sparse data points representing tissue thickness are first placed at landmarks about the scan. The generic surface is subsequently automatically placed in order to smoothly and evenly interpolate the data points. This thesis presents a new interpolation method that is well adapted to fitting a hierarchical surface to sparse data points. A reasonable facial approximation is produced from a minimal amount of data using this technique. Multiple facial base shapes are easily created by using the appropriate tissue depths for race, age, sex and body fat content. Facial details such as the eyes, nose and lips can be edited after interpolation. These basic techniques are appropriate for use in an eventual commercial 3D forensic reconstruction tool.

@MastersThesis{Archer1997,
	author = {Katrina M. Archer, M.Sc},
	title = {Craniofacial Reconstruction Using Hierarchical B-Spline Interpolation},
	school = {UBC},
	year = {1997},
	supervisor = {Rabab Ward and David R. Forsey},
}