GRID和一般raster,柵格數(shù)據(jù)與矢量數(shù)據(jù)的區(qū)別

1、GRID和一般raster的區(qū)別如下：The term raster data structure refers to a matrix composed of distinct units called pixels or cells. Each pixel or cell stores a numeric value. The pixels in a raster image usually consist of continuous brightness values represented as digital numbers. A raster image may be conver

2、ted into a raster map by using image processing techniques to label each pixel with a numeric value indicating its category or surface type. Raster maps can also be created by rasterizing existing digital vector maps.GRID is an implementation of the generic raster data structure. It uses blocks and

3、tiles for spatial indexing and an adaptive run-length compression technique for reducing storage. The values associated with the cells in a grid may be continuous or discrete. Hence, both raster images and raster maps can be stored in GRID. The operators that are part of the GRID system are designed

4、 for the analysis and overlay of raster maps. However, they may also be usefully employed for a variety of image-processing and analysis tasks.柵格數(shù)據(jù)與矢量數(shù)據(jù)柵格數(shù)據(jù)結(jié)構(gòu)基于柵格模型的數(shù)據(jù)結(jié)構(gòu)簡(jiǎn)稱柵格數(shù)據(jù)結(jié)構(gòu)，是指將空間分割成有規(guī)則的網(wǎng)格， 稱為柵格單元，在各個(gè)柵格單元上給出出相應(yīng)的屬性值來(lái)表示地理實(shí)體的一種數(shù)據(jù) 組織形式。柵格數(shù)據(jù)結(jié)構(gòu)表示的是二維表面上的要素的離散化數(shù)值，每個(gè)網(wǎng)格對(duì)應(yīng)一種屬 性。網(wǎng)格邊長(zhǎng)決定了柵格數(shù)據(jù)的精度。矢量數(shù)據(jù)結(jié)構(gòu)矢量數(shù)據(jù)結(jié)構(gòu)

5、是利用歐幾里得幾何學(xué)中的點(diǎn)、線、面及其組合體來(lái)表示地理實(shí) 體的空間分布的一種數(shù)據(jù)組合方式。矢量與柵格數(shù)據(jù)結(jié)構(gòu)的比較矢量數(shù)據(jù)結(jié)構(gòu)的優(yōu)缺點(diǎn)：優(yōu)點(diǎn)為數(shù)據(jù)結(jié)構(gòu)緊湊、冗余度低，有利于網(wǎng)絡(luò)和檢索分析，圖形顯示質(zhì)量好、 精度高；缺點(diǎn)為數(shù)據(jù)結(jié)構(gòu)復(fù)雜，多邊形疊加分析比較困難。具體來(lái)說(shuō)優(yōu)點(diǎn)有：表達(dá)地理數(shù)據(jù)精度高嚴(yán)密的數(shù)據(jù)結(jié)構(gòu)，數(shù)據(jù)量小用網(wǎng)格鏈接法能完整地描述拓?fù)潢P(guān)系，有利于網(wǎng)絡(luò)分析、空間查詢圖形數(shù)據(jù)和屬性數(shù)據(jù)的恢復(fù)、更新、綜合都能實(shí)現(xiàn)圖形輸出美觀缺點(diǎn)有：數(shù)據(jù)結(jié)構(gòu)較復(fù)雜軟件實(shí)現(xiàn)技術(shù)要求比較高多邊形疊合等分析相對(duì)困難現(xiàn)實(shí)和繪圖費(fèi)用高柵格數(shù)據(jù)的優(yōu)缺點(diǎn)：優(yōu)點(diǎn)為數(shù)據(jù)結(jié)構(gòu)簡(jiǎn)單，便于空間分析和地表模擬，現(xiàn)勢(shì)性較強(qiáng)；缺點(diǎn)為數(shù)據(jù)量大，投影轉(zhuǎn)換比較復(fù)雜。具體來(lái)說(shuō)優(yōu)點(diǎn)有：數(shù)據(jù)結(jié)構(gòu)相對(duì)簡(jiǎn)單空間分析較容易實(shí)現(xiàn)有利于遙感數(shù)據(jù)的匹配應(yīng)用和分析空間數(shù)據(jù)的疊合和組合十分容易方便數(shù)學(xué)模擬方便技術(shù)開(kāi)發(fā)費(fèi)用低缺點(diǎn)有：數(shù)據(jù)量較大，冗余度高，需要壓縮處理定位精度比矢量的低3.4.5.6.拓?fù)潢P(guān)系難以表達(dá)難以建立網(wǎng)絡(luò)連接關(guān)系投影變形花時(shí)間地圖輸出不精美兩者比較:柵格數(shù)據(jù)操作總的來(lái)說(shuō)容易實(shí)現(xiàn)，矢量數(shù)據(jù)操作則比較復(fù)雜；柵格結(jié)構(gòu)是矢量結(jié)構(gòu)在某種程度上的一種近似，對(duì)于同一地物達(dá)到于矢量數(shù)據(jù)相 同的精度需要更大量的數(shù)據(jù)；在坐標(biāo)位置搜索、計(jì)算多邊形形狀面積等方面柵格 結(jié)構(gòu)更為有效，