使用gdal.打开打开内存中的GDAL数据

Question

我有一个GDAL数据集，它只存在于内存中（inmem\ds）：

In: gdal.Info(inmem_ds)
Out:
('Driver: NUMPY/Numeric Python Array\n'
 'Files: none associated\n'
 'Size is 500, 500\n'
 'Coordinate System is:\n'
 'PROJCS["WGS 84 / UTM zone 19N",\n'
 '    GEOGCS["WGS 84",\n'
 '        DATUM["WGS_1984",\n'
 '            SPHEROID["WGS 84",6378137,298.257223563,\n'
 '                AUTHORITY["EPSG","7030"]],\n'
 '            AUTHORITY["EPSG","6326"]],\n'
 '        PRIMEM["Greenwich",0,\n'
 '            AUTHORITY["EPSG","8901"]],\n'
 '        UNIT["degree",0.0174532925199433,\n'
 '            AUTHORITY["EPSG","9122"]],\n'
 '        AUTHORITY["EPSG","4326"]],\n'
 '    PROJECTION["Transverse_Mercator"],\n'
 '    PARAMETER["latitude_of_origin",0],\n'
 '    PARAMETER["central_meridian",-69],\n'
 '    PARAMETER["scale_factor",0.9996],\n'
 '    PARAMETER["false_easting",500000],\n'
 '    PARAMETER["false_northing",0],\n'
 '    UNIT["metre",1,\n'
 '        AUTHORITY["EPSG","9001"]],\n'
 '    AXIS["Easting",EAST],\n'
 '    AXIS["Northing",NORTH],\n'
 '    AUTHORITY["EPSG","32619"]]\n'
 'Origin = (617085.000000000000000,-1512585.000000000000000)\n'
 'Pixel Size = (30.000000000000000,-30.000000000000000)\n'
 'Corner Coordinates:\n'
 'Upper Left  (  617085.000,-1512585.000) ( 67d55\' 2.38"W, 13d40\'47.58"S)\n'
 'Lower Left  (  617085.000,-1527585.000) ( 67d55\' 0.13"W, 13d48\'55.77"S)\n'
 'Upper Right (  632085.000,-1512585.000) ( 67d46\'43.12"W, 13d40\'45.26"S)\n'
 'Lower Right (  632085.000,-1527585.000) ( 67d46\'40.59"W, 13d48\'53.42"S)\n'
 'Center      (  624585.000,-1520085.000) ( 67d50\'51.55"W, 13d44\'50.54"S)\n'
 'Band 1 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 2 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 3 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 4 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 5 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 6 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 7 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n'
 'Band 8 Block=500x1 Type=Int16, ColorInterp=Undefined\n'
 '  NoData Value=-9999\n')

现在我想把这个数据集直接传递给一个使用gdal.打开（）打开其输入数据集。所以我需要一个可以传递到的物理文件路径gdal.打开(). 但我不想为了节省IO时间而把内存中的GDAL数据集写到磁盘上。在

是否有方法将内存中的数据集传递给gdal.打开()?

我尝试使用VRT数据集，但不起作用：

^{pr2}$

保存的VRT文件（mypath/测试.vrt)看起来像这样：

<VRTdataset rasterXSize="500" rasterYSize="500">
  <SRS>PROJCS["WGS 84 / UTM zone 19N",GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-69],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","32619"]]</SRS>
  <GeoTransform>  6.1708500000000000e+05,  3.0000000000000000e+01,  0.0000000000000000e+00, -1.5125850000000000e+06,  0.0000000000000000e+00, -3.0000000000000000e+01</GeoTransform>
  <VRTRasterBand dataType="Int16" band="1">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>1</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="2">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>2</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="3">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>3</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="4">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>4</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="5">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>5</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="6">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>6</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="7">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>7</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
  <VRTRasterBand dataType="Int16" band="8">
    <NoDataValue>-9999</NoDataValue>
    <SimpleSource>
      <SourceFilename relativeToVRT="0"></SourceFilename>
      <SourceBand>8</SourceBand>
      <SourceProperties RasterXSize="500" RasterYSize="500" DataType="Int16" BlockXSize="500" BlockYSize="1" />
      <SrcRect xOff="0" yOff="0" xSize="500" ySize="500" />
      <DstRect xOff="0" yOff="0" xSize="500" ySize="500" />
    </SimpleSource>
  </VRTRasterBand>
</VRTDataset>

Answer 1

您可以使用vsimem前缀将VRT写入内存，请注意数据实际上是写入内存的，因此除VRT之外的任何格式都可以显著增加内存，具体取决于实际的文件大小。在

还要注意，内存中的文件仍然存在，即使在关闭数据集句柄之后也是如此。所以当你使用完它之后，你需要自己取消链接，否则它会留下记忆。在

因此，请跟踪正在使用的内存中的位置，以便正确地取消它们的链接。在“未链接”之前写入现有的vsimem位置将不起作用，并保留原始文件。这可能有点难理解。在

要将磁盘上的文件或已打开的数据集输出到内存VRT：

ds = gdal.Translate('/vsimem/inmem.vrt', some_file_or_dataset, format='VRT')
print(ds.ReadAsArray().shape)
ds = None

再次打开：

^{pr2}$

从内存中释放文件：

gdal.Unlink('/vsimem/inmem.vrt')

我不能完全确定vsimem的作用域，所以如果你说的是“external”的另一个Python解释器，它可能无法工作。在

Answer 2

如您所见，gdal.Open采用文件路径，而内存中的数据集没有文件路径。像VRT这样的数据强制技术仍然需要文件路径（<SourceFilename>）。根据我的经验和对这个问题的研究，我认为没有一种方法可以将数据集（在内存中或基于文件的）传递到gdal.Open。您可能需要写入磁盘或尝试修改外部库。。。在