A dimensional face refers to a representation of a face using a specific number of dimensions. This can be two-dimensional (2D), three-dimensional (3D), or even one-dimensional (1D) depending on the context and application.
2D Face:
A 2D face is simply a digitized picture of a face, showing it from a single viewpoint. Think of a standard photograph or a digital image of a face. It captures height and width information but lacks depth. [Reference: Engineering definition provided]
3D Face:
A 3D face, on the other hand, provides a three-dimensional representation, capturing height, width, and depth. This allows for a more complete and accurate representation of the face's structure. This is often used in applications like:
- Sleep apnea prediction: Studies have shown that 3D facial photography can help predict sleep apnea [Reference: Predicting sleep apnea from three-dimensional face photography].
- Face recognition: 3D face recognition systems are more robust to changes in lighting and facial expressions than 2D systems [Reference: Three-Dimensional Face Recognition].
- Medical imaging: 3D face scans can be useful for various medical applications. [Reference: Validation of a low-cost portable 3-dimensional face scanner]
- Engineering simulations: 3D models of faces are used in simulations involving shock interaction with arrays of particles [Reference: Shock interaction with three-dimensional face centered cubic array].
The use of 3D face scanning technology is becoming increasingly common, with devices like the Vectra H1 using stereophotogrammetry to create detailed 3D models [Reference: Validation of a low-cost portable 3-dimensional face scanner]. The term "three-dimensional face" also appears in contexts such as analyzing the stability of pressurized tunnels [Reference: Three-dimensional face stability analysis of pressurized tunnels]. Furthermore, makeup products are sometimes described as creating a "three-dimensional face" by highlighting and contouring [Reference: Glitter Powder Highlighter Makeup, Body Brightens].
1D Face:
The term "1D face" is less common and used in a more abstract sense. One example comes from a blog discussing the concept of a "one-dimensional face" in a social context, referring to a limited or superficial representation of a person [Reference: One dimensional face – The Real Beauty Edit]. Another instance uses "1D" in the chemical context of a one-dimensional material's structure [Reference: Highly efficient self-trapped exciton emission in a one-dimensional].
Dimensionality of Facial Features:
The dimensionality of facial features can be described using 2D (height and width) and 3D (height, width, and depth) attributes. [Reference: Dimensional Face - an overview | ScienceDirect Topics] There are also discussions of 2D presentation attack detection in security applications [Reference: A Novel Active Solution for Two-Dimensional Face Presentation].
