Availability of ‘biometrics’ technology provides controls for verifying true identity of an individual. These controls are automated processes that recognize physiological characteristics such as fingerprints, face, eyes, DNA etc. of a living person which are not easy to forge as they are attributes of an individual gifted by nature. There are also automated processes that recognize individual behaviors such as handwriting style, key stroke patterns etc. (Lin, 2000)
Physiological controls are more stable when compared with behavioral controls. The main reason is that the features of physiological controls are non-alterable unless some serious injury is inflicted on a living being. On the other hand the patterns of behavior controls fluctuate with the mood and activities of an individual. In real-life, it is found that verification of physiological attributes is although very accurate, yet it is far more intrusive than the behavior attributes (Lin, 2000)
One of the few biometrics controls that have the merits of both low intrusiveness and high accuracy is the Face Recognition technology. Researches in the field of image processing, security and psychology were attracted towards the concepts of computer vision which led to the designing of face recognition technology. (Lin, 2000)
The real-world image has only size in inches or centimeters. The capturing device such as camera or scanners uses digitization process through which it stores the number of pixels that contains in an image. It is called Resolution which is of two types; Spatial Resolution and Colour Resolution (JISC Digital Media, 2006)
The capturing device in Spatial Resolution is concerned with the frequency at which samples are taken from the real-world object or art-work. Frequency is mostly expressed as samples per inch (spi) when scanning and pixels per inch (ppi) when processing the digital image. The resolution to use for capturing an image is dependent mostly on its ‘end-use’.