utils.py 文件源码

def dump_raster(rast, rast_path, xoff=0, yoff=0, driver='GTiff', nodata=None):
    '''
    Creates a raster file from a given GDAL dataset (raster). Arguments:
        rast        A gdal.Dataset; does NOT accept NumPy array
        rast_path   The path of the output raster file
        xoff        Offset in the x-direction; should be provided when clipped
        yoff        Offset in the y-direction; should be provided when clipped
        driver      The name of the GDAL driver to use (determines file type)
        nodata      The NoData value; defaults to -9999.
    '''
    driver = gdal.GetDriverByName(driver)
    sink = driver.Create(rast_path, rast.RasterXSize, rast.RasterYSize,
        rast.RasterCount, rast.GetRasterBand(1).DataType)
    assert sink is not None, 'Cannot create dataset; there may be a problem with the output path you specified'
    sink.SetGeoTransform(rast.GetGeoTransform())
    sink.SetProjection(rast.GetProjection())

    for b in range(1, rast.RasterCount + 1):
        dat = rast.GetRasterBand(b).ReadAsArray()
        sink.GetRasterBand(b).WriteArray(dat)
        sink.GetRasterBand(b).SetStatistics(*map(np.float64,
            [dat.min(), dat.max(), dat.mean(), dat.std()]))

        if nodata is None:
            nodata = rast.GetRasterBand(b).GetNoDataValue()

            if nodata is None:
                nodata = -9999

        sink.GetRasterBand(b).SetNoDataValue(np.float64(nodata))

    sink.FlushCache()