Terrain modeling using dominant points

Digital representation of terrain surface is an important research area. A number of techniques have been proposed to represent the terrain surface in a realistic manner. They have been broadly categorized as 2D or 3D terrain models. Each of these models has its own merits and demerits. An ideal model will capture the minute details of the terrain, thus requiring more sample points of the terrain, whereas an optimum model will require the dominant features to represent the terrain effectively. Hence there is a debate amongst researchers on which are the ¿appropriate level of detail of the terrain which captures the terrain features without compromising the signature of the terrain¿. The Very Important Point (VIP) algorithm captures the essential terrain samples which encode the dominant physical characteristics of the terrain surface so that the properties such as height, slope, aspect of the terrain can be preserved accurately. The level of details or the dominant points captured through VIP algorithm is decided through a major of significance of the sample point with respect to its surroundings. The major of significance is empirically being decided through a threshold value in most of the techniques which select the sample points. This paper attempts to investigate and understand the optimum threshold value of the undulating terrain for sampling the dominant points. The threshold value of VIP algorithms which filters the dominant points is investigated for different types of terrain. The range of the threshold value which filters the optimum number of terrain points so that the important physical characteristic of the terrain is preserved is derived from the experiment.