Koichi Anada

Ridge Detection with the Steepest Ascent Method

We propose a new method to detect ridges from digital elevation map (DEM) data. We call it “the steepest ascent method” which is based on steepest ascent lines obtained by selecting the maximum inclined direction from eight neighbors. Then ridge lines are extracted by their steepest ascent lines on a surface. In this paper it is shown that our method is able to detect ridge lines sharply. Besides we claim that our algorithm is simple and suitable for huge area such as the entire area of Japan. Finally, we give the ridge detected terrain map of the entire area of Japan and Korea by applying “the steepest ascent method”.

A resolution reduction method for multi-resolution terrain maps

Raster images such as raster terrain maps are commonly used in computer graphics. For rapid processing such as rendering and rapid feature extraction, rapid resolution reduction methods are required that keep the quality of huge images. This study deals with the resolution reduction methods.

Contraction of surfaces by harmonic mean curvature flows and nonuniqueness of their self similar solutions

Abstract. We consider the evolution equations

8k-ary Grid graph models of tabular forms

F_t=-(H_{-1})^{\alpha}\nu

Tabular form editing with a hexadecimal grid graph model

, where

A data structure for triangular dissection of multi-resolution images

0<\alpha<1

Reduction of resolution for binary images by an octal grid graph representation model

,

A Method of Ridge Detection in Triangular Dissections Generated by Homogeneous Rectangular Dissections

\nu

A Comparison of Ridge Detection Methods for DEM Data

is the unit outer normal vector and

Row manipulation in the heterogeneous tabular forms with a hexadecimal grid graph model

H_{-1}