Automatic fingerprint recognition typically goes through a series of processes, including ridge orientation estimation, segmentation, enhancement, minutiae detection and matching.

And an area is set up as the filtering region to enhance a fingerprint image,which can be modulated automatically according to the change in local ridge orientation and frequency.

The friction and wear behaviour of nylon rubbing against different texture direction steel discs,such as parallel,helix and multidirectional texture steel discs were investigated.

After a simple analysis of the intra prediction,a new fast algorithm is proposed,which is based on estimating the image texture direction.

For the sake of reducing data process and improving matching speed,fingerprint texture is filtered and smoothed and texture direction information is extracted.

We estimate the fringe orientation firstly and use a special filter to depress orientation noises.

Because the contoured window is obtained from fringe orientation.

In this paper, a simple method for estimating fringe orientation is presented, and a method of picking up the fringe skeletons of speckle pattern from fringe orientation is discussed.

A fingerprint enhancement algorithm based on Gabor filter and its application is developed in this paper, and a method forridge orientation acquirement is improved, and the orientation map is more accurate.

A method for ridge orientation acquirement is improved and a new method for ridge frequency acquirement is brought out.

The paper proposes an algorithm for distilling fingerprint orientation in the multilevel block size, which adjusts the fingerprint orientation in the small bl.