A new method of enhancing fingerprint images is described, based upon nonstationary directional Fourier domain filtering. Fingerprints are first smoothed using a directional filter whose orientation… Expand

A simple mathematical model is developed which computes fingerprint local ridge orientation from core and delta positions and provides an intelligent tool for resolving ambiguities due to the periodic nature of orientation.Expand

This paper considers the generation of two-channel perfect reconstruction quadrature mirror filter banks corresponding to compactly supported orthonormal wavelets.Expand

A common approach to signal or image processing using the discrete Fourier transform (DFT) is to extract a portion of the signal by windowing, and then to form the DFT of the window contents. By… Expand

The authors present a strategy for generating optimal quantisation tables for use in JPEG image compression and its extension to general block sizes. Directly optimised quantisation tables were… Expand

An algorithm is developed to apply Hann, Hamming, Blackman and related windows directly in the transform domain for the discrete cosine transform and discrete sine transform.Expand

Presents a strategy for generating optimal JPEG quantization tables to approximate a target compression ratio. This uses a model to express the quantization coefficients as functions of compression… Expand