The remarkable characteristics of raster structure are obvious attributes, implicit location, that is, data directly records the attributes of the pointer or attributes themselves, and the location is converted to corresponding coordinates according to row and column numbers, that is to say, location is based on the location of data in the data set. Remote sensing image is a typical raster structure, and the number of each pixel represents the gray level of the image. A surface or region is represented by a set of adjacent grid cells with regional attributes, and each grid cell can have more than two adjacent cells belonging to the same region. A group of adjacent grid cells along the line of linear objects are represented by a maximum of two adjacent cells on the line. As shown in Figure 7-4, in a grid structure, points are represented by a grid cell. Therefore, the raster structure is a data organization that represents the distribution of spatial objects or phenomena by regular arrays, and each data in the organization represents the non-geometric attributes of objects or phenomena. Each grid is defined as a pixel or a pixel by rows and columns, and contains a code to represent the attribute type or magnitude of the pixel, or only a pointer to its attribute record. It refers to dividing the earth’s surface into uniform and closely adjacent grid arrays. Grid structure is the simplest and most direct spatial data structure.

Raster data structure