Ridge detection in digital imagery, unlike edge detection, is an area that has received relatively little attention. Ridges are long, narrow structures that are perceptibly brighter than the background. Examples of ridges include roads in aerial images and vessels in medical images. The ability to rapidly and accurately label ridge pixels in a digital image is an important first step in many co...

Ridges and ravines are the main components constituting a "ngerprint. Traditional automatic "ngerprint identi"cation systems (AFIS) are based on minutiaematching techniques. The minutiae for "ngerprint identi"cation are de"ned by ridge termination and ridge bifurcation. Most AFIS perform ridge line following process to automatically detect minutiae based on binary or skeleton "ngerprint image. ...

A novel method for detecting altered fingerprints using scars, minutiae density and ridge discontinuity is proposed here.This paper mainly focuses on FFT enhancement for ridge discontinuity analysis and use of scars along with ridge discontinuity and minutiae density for alteration detection. The scar is detected by adaptive average filtering and thresholding. This method is found suitable for ...

In this paper we propose a new ridge/valley detection method in images based on the difference of rotating Gaussian semi filters. The novelty of this approach resides in the mixing of ideas coming both from directional filters and DoG method. We obtain a new ridge/valley anisotropic DoG detector enabling very precise detection of ridge/valley points. Moreover, this detector performs correctly a...

The problem of reconstructing the 3D face using one image captured from a viewpoint arises in many fields of science and engineering, this paper propose the novel approach for reconstructing the 3D face by using ellipse fitting technique from only one 2.5D image. The 2.5D face image is captured from any viewpoint between -45 degree and +45 degree. The cross section across the head is fitted by ...

Generally the ridge crests spread in the dinaridic direction that is NW-SE what is mainly the characteristic of the older tectonic phase. The turn point in morphogenesis of the External Dinarides and thus of the Velebit Mt. occurs with the change in the shift of the Adriatic microplate toward N and NNW what is reflected on the orientation and morphology of the ridge crests as well as on the oth...

In this paper an existing ridge detector based on the Hessian tensor and a new one based on the structure tensor are evaluated for use in portal/simulator imaging. Tensor smoothing is introduced as a scaling parameter. By changing this scale (as opposed to the image scale) the detectors can be tuned to suppress spurious ridges without moving them. Desirable ridge detector properties for portal/...

Due to the undulating terrain, earthwork estimation was very difficult in the planning and design of land consolidation projects in the hilly areas. A new approach was proposed to estimate the earthwork of sloped terraces according to map features of planning and design of land consolidation in this paper. It was achieved by applying digital elevation model (DEM) theory and statistical function...

This paper presents a novel texture boundary detector called the standard deviation ridge detector. At 43.29 frames per second, it is one of the few texture boundary detectors that can run in realtime. With its Berkeley segmentation benchmark F-statistic of 0.62, the algorithm outperforms all existing realtime texture boundary detectors. The use of the boundary detector would induce noticable i...