使用GDAL进行栅格数据读取示例

当然,使用GDAL可以对其支持的数据进行操作,不局限在栅格数据。但目前主要解决的问题是栅格数据,更具体一点是针对ENVI的标准数据格式。
以下程序仅作为一个简单的应用示例,主要参考了http://www.gdal.org/gdal_tutorial.html中的内容。使用时需要用到一下头文件:
cpl_config.h
cpl_conv.h
cpl_error.h
cpl_minixml.h
cpl_port.h
cpl_string.h
cpl_vsi.h
gdal.h
gdal_frmts.h
gdal_priv.h
gdal_version.h
另外需要连接gdal.lib(静态链接)或者gdal_i.lib(动态链接)。程序没有特别的功能,仅作示例而已。
gdal_sample.cpp
///
#include "./gdal/gdal_priv.h"
int main(int argc, char **argv)
{
if(argc != 2)
{
printf( "Usage: gdal_sample /n" );
return 0;
}
char *pszFilename;
pszFilename = argv[1];

// Opening the File
GDALDataset*poDataset;
GDALAllRegister();
poDataset = (GDALDataset *) GDALOpen( pszFilename, GA_ReadOnly );
if( poDataset != NULL )
{
// Getting Dataset Information
doubleadfGeoTransform[6];
printf( "Driver: %s/%s/n",
poDataset->GetDriver()->GetDescription(),
poDataset->GetDriver()->GetMetadataItem( GDAL_DMD_LONGNAME ) );
printf( "Size is %dx%dx%d/n",
poDataset->GetRasterXSize(), poDataset->GetRasterYSize(),
poDataset->GetRasterCount() );
if( poDataset->GetProjectionRef()!= NULL )
printf( "Projection is `%s'/n", poDataset->GetProjectionRef() );
if( poDataset->GetGeoTransform( adfGeoTransform ) == CE_None )
{
printf( "Origin = (%.6f,%.6f)/n",
adfGeoTransform[0], adfGeoTransform[3] );
printf( "Pixel Size = (%.6f,%.6f)/n",
adfGeoTransform[1], adfGeoTransform[5] );
}
// Fetching a Raster Band
GDALRasterBand*poBand;
intnBlockXSize, nBlockYSize;
intbGotMin, bGotMax;
doubleadfMinMax[2];

poBand = poDataset->GetRasterBand( 1 );
poBand->GetBlockSize( &nBlockXSize, &nBlockYSize );
printf( "Block=%dx%d Type=%s, ColorInterp=%s/n",
nBlockXSize, nBlockYSize,
GDALGetDataTypeName(poBand->GetRasterDataType()),
GDALGetColorInterpretationName(
poBand->GetColorInterpretation()) );
adfMinMax[0] = poBand->GetMinimum( &bGotMin );
adfMinMax[1] = poBand->GetMaximum( &bGotMax );
if( ! (bGotMin && bGotMax) )
GDALComputeRasterMinMax((GDALRasterBandH)poBand, TRUE, adfMinMax);
printf( "Min=%.3fd, Max=%.3f/n", adfMinMax[0], adfMinMax[1] );

if( poBand->GetOverviewCount() > 0 )
printf( "Band has %d overviews./n", poBand->GetOverviewCount() );
if( poBand->GetColorTable() != NULL )
printf( "Band has a color table with %d entries./n",
poBand->GetColorTable()->GetColorEntryCount() );
// Reading Raster Data
float *pafScanline;
intnXSize = poBand->GetXSize();
pafScanline = (float *) CPLMalloc(sizeof(float)*nXSize);
poBand->RasterIO( GF_Read, 0, 0, nXSize, 1,
pafScanline, nXSize, 1, GDT_Float32,
0, 0 );
// Closing the Dataset
GDALClose(poDataset);
}
【使用GDAL进行栅格数据读取示例】return 0;
}

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