Moving cube algorithm (Marching cubes algorithm)

Baidu Encyclopedia:

There are two main kinds of methods for three-dimensional reconstruction of medical images: one is three-dimensional surface rendering and the other is three-dimensional body drawing. Volume rendering can reflect the structure of the object more realistically, but because of its large computational capacity, even the use of high-performance computers can not meet the needs of interactive operation in practical applications. So Polygon Drawingis the main algorithm of three-dimensional reconstruction of medical image. • Marchingcubes (MC) algorithm is a classical algorithm in polygon rendering algorithm, it is a voxel-level reconstruction method, which was proposed by W.lorensen and others in 1987. Because its principle is simple and easy to realize, it has been widely used. The MC algorithm is actually a Divide and conquerThe method, because it distributes the extract of the contour in each individual (voxel)。 For each treated voxel, a triangular patch is approximated to its inner contour. Each voxel is a small cube (cube) that "scans" each voxel during the process of constructing triangular patches, as if it were a processor moving on these voxel, and hence its name. • In the process of contour extraction, a series of two-dimensional slicing data is considered as a three-dimensional data field, from which a substance with certain thresholds is extracted and connected into triangular patches in some topological form, so The MC algorithm is also known as the "Contour Extraction" (isosurfaceextraction) algorithm。·· In medical applications, the use of MC algorithm can reconstruct the external contour of human body, internal tissue organs, so that doctors can directly in the three-dimensional image of the organs of interest and the surrounding tissues of the spatial relationship. • In MC Algorithms, assume that the original data is a discrete three-dimensional spatial rule data field for medical diagnostic tomography (CT) The image belongs to this type. • The basic idea of MC algorithm is to deal with the cube in the data field, find the cube intersecting with the equivalent plane, and use linear interpolation to calculate the intersection of the contour and the cube edge. According to the relative position of each vertex and contour of the cube, the contour is connected with the intersection of the cube edge in a certain way, as an approximation representation of the equivalent plane within the cube. • Thus, the equivalent surface of each unit in MC algorithm is extracted two main calculations: (1) The equivalent surface of the voxel is approximated by the triangular plane, and (2) the vertex method of triangular patches is calculated.

Moving cube algorithm (Marching cubes algorithm)