Use of Miniature Step Gauges to Assess the Performance of 3D Optical Scanners and to Evaluate the Accuracy of a Novel Additive Manufacture Process.

In this work, we show how miniature step gauges featuring unidirectional and bidirectional lengths can be used to assess the performance of 3D optical scanners as well as the accuracy of novel Additive Manufacturing (AM) processes. A miniature step gauge made of black polyphenylene sulfide (PPS) was used for the performance verification of three different optical scanners: a structured light scanner (SLS), a laser line scanner (LLS), and a photogrammetry-based scanner (PSSRT), having comparable resolutions and working volumes. Results have shown a good agreement between the involved scanners, with errors below 5 μm and expanded uncertainties below 10 μm.

Analysis of Shape Geometry and Roughness of Ti6Al4V Parts Fabricated by Nanosecond Laser Ablation.

Laser milling is a micro-machining process that uses a laser beam as a tool to remove material through the layer-by-layer ablation mechanism. Generally in laser ablation, the quality of parts is reduced by melt accretions and thermal damage; therefore, this problem is reduced with shorter pulse duration, although ablation efficiency decreases as well. Thus, laser ablation in the nanosecond range still offers a good compromise between process quality and efficiency.

Application of off-the-shelf stereo-cameras for the 3D assessment of morphometric variations caused by rhinoplasty.

The present paper shows how a non-invasive and low-cost photogrammetric stereo device allows the assessment of morphometric variations of the nose following rhinoplasty. Six female patients, aged between 24 and 37 years, underwent 3D stereo-photogrammetric scanning. Three-dimensional computerised models were generated, extracting also information related to the coordinates of facial landmarks, distances between landmarks, angles, in pre- and postoperative situation.

Photogrammetric 3D skull/photo superimposition: A pilot study.

The identification of bodies through the examination of skeletal remains holds a prominent place in the field of forensic investigations. Technological advancements in 3D facial acquisition techniques have led to the proposal of a new body identification technique that involves a combination of craniofacial superimposition and photogrammetry. The aim of this study was to test the method by superimposing various computerized 3D images of skulls onto various photographs of missing people taken while they were still alive in cases when there was a suspicion that the skulls in question belonged to them.

Three-Dimensional Anthropometric Database of Attractive Caucasian Women: Standards and Comparisons.

The aim of this paper is to develop a database to determine a new biomorphometric standard of attractiveness. Sampling was carried out using noninvasive three-dimensional relief methods to measure the soft tissues of the face. These anthropometric measurements were analyzed to verify the existence of any canons with respect to shape, size, and measurement proportions which proved to be significant with regard to the aesthetics of the face.

Is principal component analysis an effective tool to predict face attractiveness? A contribution based on real 3D faces of highly selected attractive women, scanned with stereophotogrammetry.

In the literature, several papers report studies on mathematical models used to describe facial features and to predict female facial beauty based on 3D human face data. Many authors have proposed the principal component analysis (PCA) method that permits modeling of the entire human face using a limited number of parameters. In some cases, these models have been correlated with beauty classifications, obtaining good attractiveness predictability using wrapped 2D or 3D models.

Three-dimensional methodology for photogrammetric acquisition of the soft tissues of the face: a new clinical-instrumental protocol.

Background: The objective of this study is to define an acquisition protocol that is clear, precise, repeatable, simple, fast and that is useful for analysis of the anthropometric characteristics of the soft tissue of the face.

Methods: The analysis was carried out according to a new clinical-instrumental protocol that comprises four distinct phases: (1) setup of portable equipment in the space in which field analysis will be performed, (2) preparation of the subject and spatial positioning, (3) scanning of the subject with different facial expressions, and (4) treatment and processing of data. The protocol was tested on a sample comprising 66 female subjects (64 Caucasian, 1 Ethiopian, and 1 Brazilian) who were the finalists of an Italian national beauty contest in 2010.

Noninvasive computerized scanning method for the correlation between the facial soft and hard tissues for an integrated three-dimensional anthropometry and cephalometry.

Objectives: The article describes a new methodology to scan and integrate facial soft tissue surface with dental hard tissue models in a three-dimensional (3D) virtual environment, for a novel diagnostic approach.The facial and the dental scans can be acquired using any optical scanning systems: the models are then aligned and integrated to obtain a full virtual navigable representation of the head of the patient.

Methods: In this article, we report in detail and further implemented a method for integrating 3D digital cast models into a 3D facial image, to visualize the anatomic position of the dentition.