使用GDAL从tif文件创建shapefile

时间:2014-07-30 14:33:32

标签: python tiff shapefile gdal

我使用库gdal加载tiff文件并创建shapefile。

当我使用QGIS GUI加载shapefile时,高程上没有信息。

我希望在改造时保持高程。

import os
from osgeo import gdal,ogr,osr,gdalnumeric
import numpy as np

# this allows GDAL to throw Python Exceptions
gdal.UseExceptions()


print "reading tif file..."
try:
    ds = gdal.Open( "file.tif" )
except RuntimeError, e:
    print 'Unable to open file'
    print e
    sys.exit(1)

try:
    srcband = ds.GetRasterBand(1)
except RuntimeError, e:
    # for example, try GetRasterBand(10)
    print 'Band ( %i ) not found' % band_num
    print e
    sys.exit(1)


band = ds.GetRasterBand(1)
# elevation 2D numpy array
elevation = band.ReadAsArray()

# create shapefile datasource from geotiff file
#
print "creating shapefile..."
dst_layername = "Shape"
drv = ogr.GetDriverByName("ESRI Shapefile")
dst_ds = drv.CreateDataSource( dst_layername + ".shp" )
dst_layer = dst_ds.CreateLayer(dst_layername, srs = None )
gdal.Polygonize( srcband, None, dst_layer, -1, [], callback=None 

的问候,

1 个答案:

答案 0 :(得分:1)

这是你的脚本,它被更新以创建一个名为" elevation"的字段。并将带1中的栅格值提取到该字段中。

import os
from osgeo import gdal,ogr
import sys 

# mapping between gdal type and ogr field type
type_mapping = { gdal.GDT_Byte: ogr.OFTInteger,
                 gdal.GDT_UInt16: ogr.OFTInteger,   
                 gdal.GDT_Int16: ogr.OFTInteger,    
                 gdal.GDT_UInt32: ogr.OFTInteger,
                 gdal.GDT_Int32: ogr.OFTInteger,
                 gdal.GDT_Float32: ogr.OFTReal,
                 gdal.GDT_Float64: ogr.OFTReal,
                 gdal.GDT_CInt16: ogr.OFTInteger,
                 gdal.GDT_CInt32: ogr.OFTInteger,
                 gdal.GDT_CFloat32: ogr.OFTReal,
                 gdal.GDT_CFloat64: ogr.OFTReal}

# this allows GDAL to throw Python Exceptions
gdal.UseExceptions()


print "reading tif file..."
try:
    ds = gdal.Open(sys.argv[1])
except RuntimeError, e:
    print 'Unable to open file'
    print e
    sys.exit(1)

try:
    srcband = ds.GetRasterBand(1)
except RuntimeError, e:
    # for example, try GetRasterBand(10)
    print 'Band ( %i ) not found' % 1
    print e
    sys.exit(1)

# create shapefile datasource from geotiff file
print "creating shapefile..."
dst_layername = "Shape"
drv = ogr.GetDriverByName("ESRI Shapefile")
dst_ds = drv.CreateDataSource( "poly_out.shp" )
dst_layer = dst_ds.CreateLayer(dst_layername, srs = None )
raster_field = ogr.FieldDefn('elevation', type_mapping[srcband.DataType])
dst_layer.CreateField(raster_field)
gdal.Polygonize( srcband, None, dst_layer, 0, [], callback=None)