GDAL学习
GDAL is a C++ translator library for more than 200 raster and vector geospatial data formats. It is released under an X/MIT style Open Source license by the Open Source Geospatial Foundation. As a library, it presents a single raster abstract data model and single vector abstract data model to the calling application for all supported formats. It also comes with a variety of useful command line utilities for data translation and processing. It offers an API for a variety of languages such as C, C++, Python, Perl, C# and Java
The related OGR library (OGR Simple Features Library), which is part of the GDAL source tree, provides a similar ability for simple features vector graphics data.
GDAL 是 Geospatial Data Abstraction Library 的缩写, 最开始的时候是一个用来处理栅格空间数据的类库,OGR 则是则是来处 理矢量数据的。 后来,这两个库合并成为合并成为一个,在下载安装的时候,都是使用GDAL 这一个名字。
由于 GDAL 对多种栅格数据格式都提供了支持,很多软件都使用它作为底层数据处理的库。 这其中比较有名的有:ArcGIS、Google Earth、OpenEV、GRASS GIS、OSSIM、Quantum GIS、MapServer、World Wind.
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Core features
- Reading and writing of raster and vector geospatial formats 读写矢量和栅格地理空间数据
- Data format translation 数据格式转换
- Geospatial processing: subsetting, image warping, reprojection, mosaicing, tiling, DEM processing 地理空间数据处理：裁剪 投影 镶嵌 等
Implemented Standards
- Catalogue Service for the Web (CSW)
- Geographic JSON (GeoJSON)
- Georeferenced Tagged Image File Format (GeoTIFF)
- Geography Markup Language (GML)
- Keyhole Markup Language (KML)
- OpenStreetMap (OSM)
- Simple Features for SQL (SFSQL)
- Web Coverage Service (WCS)
- Web Feature Service (WFS)
- Well-Known Binary (WKB)
- Well-Known Text (WKT)
- Web Map Service (WMS)
- Web Map Tile Service (WMTS)
读取矢量shp案例：
import sys
try:
from osgeo import ogr, osr, gdal
except:
sys.exit('ERROR: cannot find GDAL/OGR modules')
# try:
# from osgeo import ogr
# except:
# import ogr
driver = ogr.GetDriverByName('ESRI Shapefile')
filename='D:/ArcGIS Data/Chinacity.shp'
dataSource = driver.Open(filename,0)
if dataSource is None:
print('could not open')
sys.exit(1)
print('done')
layer = dataSource.GetLayer(0)
n = layer.GetFeatureCount()
print(n)
extent = layer.GetExtent()
print('extent:', extent)
print('ul:', extent[0], extent[3])
print('lr:', extent[1], extent[2])
参考：
https://gdal.org/ GDAL documentation
https://www.osgeo.cn/pygis/gdal-gdalintro.html 中文教程
https://www.osgeo.cn/python_gdal_utah_tutorial/ch02.html?from=groupmessage
https://pcjericks.github.io/py-gdalogr-cookbook/ Python GDAL/OGR Cookbook!
https://pypi.org/project/GDAL/ python 包
