The way is to model a curve segment of palm vein textures by a number of variable-length line segments through media value iteration and let distance criterion control the fitting error,under permitted error,using the included angles sequence between a pair of neighboring line segments to represent the curve segment.

An adaptive two-pass rank order filter based on iterative median filter;

In this paper,two low-pass filtering methods,the median-iteration filtering technique in space domain and the discrete-cosine-transform (DCT)filtering technique in frequency domain,are proposed.

Aiming at problems in current study of sonar image enhancement,a new enhancement method based iterative threshold was presented,the criterion function and frequency response were used to evaluate and compare current image enhancement arithmeti.

A modification to Linearly Decreasing Weight strategy in standard Particle Swarm Optimization is taken by introducing descending index and iterative threshold.

The identification card scanned image is seriously affected by laser restraining false shadow grid, several binarization methods of document image are studied according to this characteristic, an image binarization method is proposed , which is called iterative threshold methodbased on the neighborhood feature of the pixels .