Distance transform

About: Distance transform is a research topic. Over the lifetime, 2886 publications have been published within this topic receiving 59481 citations.

Multiresolution distance volumes for progressive surface compression

Abstract: We present a surface compression method that stores surfaces as wavelet-compressed signed-distance volumes. Our approach enables the representation of surfaces with complex topology and arbitrary numbers of components within a single multiresolution data structure. This data structure elegantly handles topological modification at high compression rates. Our method does not require the costly and sometimes infeasible base mesh construction step required by subdivision surface approaches. We present several improvements over previous attempts at compressing signed-distance functions, including an O(n) distance transform, a zero set initialization method for triangle meshes, and a specialized thresholding algorithm. We demonstrate the potential of sampled distance volumes for surface compression and progressive reconstruction for complex high genus surfaces.

Moving object detection system

Abstract: In a moving object detection system, an edge image is generated from captured images taken by CCD cameras and a moving object distance image indicative of a distance to a moving object (such as a human being) is generated by extracting pixel corresponding thereto. Then, pixels in the moving object distance image are summed to generate a histogram and a profile extraction region is set in the moving object distance image with its center line focusing on a position whose histogram is greatest, while the edge image is superposed on the moving object distance image to correct the center line of the profile extraction region such that the moving object is detected by extracting its profile in the region. With this, it becomes possible to detect the moving objects respectively even when the two or more objects are present in neighborhood.

Underwater Single Image Restoration Using Dark Channel Prior

Abstract: The underwater vision is highly spoiled by the underwater degradation effects. As light propagates in the water or other participative mediums, it suffers from a substantial scattering effect that produces poor image quality. Based on a physical model that describes this phenomenon it is possible to recover an haze-free image. But, for this procedure to succeed, it is necessary to obtain certain parameters from the model. With an adaptation of the Dark Channel Prior, proposed by this paper, we are able to obtain a rough distance map estimative. With this, and some model simplifications, we are able to successfully obtain the restoration of the image.

Weighted digital distance transforms in four dimensions

Abstract: A digital distance transformation converts a binary image in Zn to a distance transform, where each picture element in the foreground (background) has a value measuring the closest distance to the background (foreground). In a weighted distance transform, the distance between two points is defined by a minimal path consisting of a number of steps between neighbouring picture elements, where each type of possible step is given a length-value, or a weight. In 4D, using 3i?3i?3i?3 neighbourhoods, there are four different weights. In this paper, optimal real and integer weights are computed for one type of 4D weighted distance transforms. The most useful integer transform is probably {3,4,5,6}, but there are a number of other ones listed. Two integer distance transforms are illustrated by their associated balls.

Filling Holes in Complex Surfaces using Oriented Voxel Diffusion

Abstract: Range scanning devices often yield imperfect surface sampling for real-world models with complex features. These holes in the surface are commonly filled with smooth patches conforming to the boundaries. We introduce an oriented voxel diffusion method to fill holes in complex surfaces. First, an initial field of oriented distance is measured according to the existing surface. The implicit surface of the oriented distance field coincides with the existing surface. Second, the oriented distance field diffuses inward the hole until the implicit surface converges. Particularly, the orientation information in the distance field is used to control the diffusion direction accurately. Therefore this method is able to restore the sharp features.