人脸识别论文文献翻译中英文

人脸识别论文文献翻译中英文

人脸识别论文中英文

附录(原文及译文)

翻译原文来自

Thomas David Heseltine BSc. Hons. The University of York

Department of Computer Science

For the Qualification of PhD. -- September 2005 -

《Face Recognition: Two-Dimensional and Three-Dimensional Techniques》

4 Two-dimensional Face Recognition

4.1 Feature Localization

Before discussing the methods of comparing two facial images we now take a brief look at some at the preliminary processes of facial feature alignment. This process typically consists of two stages: face detection and eye localisation. Depending on the application, if the position of the face within the image is known beforehand (for a cooperative subject in a door access system for example) then the face detection stage can often be skipped, as the region of interest is already known. Therefore, we discuss eye localisation here, with a brief discussion of face detection in the literature review(section 3.1.1).

The eye localisation method is used to align the 2D face images of the various test sets used throughout this section. However, to ensure that all results presented are

representative of the face recognition accuracy and not a product of the performance of the eye localisation routine, all image alignments are manually checked and any errors corrected, prior to testing and evaluation.

We detect the position of the eyes within an image using a simple template based method. A training set of manually pre-aligned images of faces is taken, and each image cropped to an area around both eyes. The average image is calculated and used as a template.

Figure 4-1 - The average eyes. Used as a template for eye detection.

Both eyes are included in a single template, rather than

individually searching for each eye in turn, as the characteristic symmetry of the eyes either side of the nose, provides a useful feature that helps distinguish between the eyes and other false positives that may be picked up in the background. Although this method is highly susceptible to scale(i.e. subject distance from the

camera) and also introduces the assumption that eyes in the image appear near horizontal. Some preliminary experimentation also reveals that it is advantageous to include the area of skin just beneath the eyes. The reason being that in some cases the eyebrows can closely match the template, particularly if there are shadows in the eye-sockets, but the area of skin below the eyes helps to distinguish the eyes from eyebrows (the area just below the eyebrows contain eyes, whereas the area below the eyes contains only plain skin).