The emergence of a more comprehensive standard has grown out of an amalgamation of two existing standards. The ANSI/NIST standard and the FBI standard referred to as EFTS. Both standards contribute different specifications to the proposed standard. Obviously, the crux of biometric measurement is the ability to increase confidence in identification. Therefore precision is a vital aspect in development. This standard has two key components, message format and image quality.
Any system claiming to be in conformance with the new standard must be in conformance with the ANSI standard record files. At a minimum, each message must have a Type 1, a Type 2, and one other record type. Type 1 is called the Transaction Record. This record provides information describing type and use of transaction involved, a listing by type of the logical records included in the file, the originator or the source of the physical record, and other useful information items. Type 2 records provide details about an individual or an error message. There are seven other types of records that can be sent. These are all image records based on different resolution and grayscale levels.
The new standard requires conformance to the image quality specifications established in both the ANSI and the EFTS standards. The ANSI standard covers the minimum scan rate in picture elements, also known as pixels per inch. Also covered is the pixel depth, which is the number of gray levels possible per pixel. Acceptable transmission rates of these images are dictated by Section 5 of the ANSI standard.
EFTS image quality standards specify the data acquisition standards, such as the modulation transfer function (MTF) and the signal-to-noise ratio. The MTF measures how much of the fingerprint data can be acquired. Thus it is a combination of the quality of the optics, the scanner, the scanner detectors, and the analog-to-digital converters. The EFTS also specifies the threshold for display devices such as printers and CRT's for the fingerprint data.
One area yet to be decided but well researched is what compression algorithms to use. Currently the FBI uses the Wavelet Scalar Quantization (WFQ) specification. However most vendors have been their using their own algorithms. Currently no compression technique is accepted by the FBI other than the WSQ. Therefore it is likely that the standard will adopted. his as its solution. The FBI has already developed a test methodology for certifying WSQ software solution.