一个GDAL的读写数据例子

//

#include "stdafx.h"
#include "fangshibo.h"

#include


#include
///gdal头文件
#include "..\\include\\gdal.h"
#include "..\\include\\gdal_priv.h"
#include "..\\include\\ogr_srs_api.h"
#include "..\\include\\cpl_string.h"
#include "..\\include\\cpl_conv.h"
#pragma comment (lib,"..\\lib\\gdal_i.lib")
/////////////////////////////////////////////////////////////////////////////


#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// The one and only application object

CWinApp theApp;
using namespace std;

///////////////////////
void MaxNDVI(vector files,CString maxNDVfile)
{
// GDALAllRegister();
vector datasets;
//打开文件
for(int i=0;i{
CString filename=files[i];
GDALDataset *tmpDataset = (GDALDataset *) GDALOpen( files[i], GA_ReadOnly);
if(tmpDataset!=NULL)
{
datasets.push_back(tmpDataset);
}
else
{
fprintf( stderr, "GDALOpen failed - %d\n%s\n", CPLGetLastErrorNo(), CPLGetLastErrorMsg() );
}
tmpDataset=NULL;//以后再释放
}
////读取数据咯，按行来读取
//GDALDir
if(datasets.size()==0)return;
GDALDataset *tmpDataset=datasets[0];
if(tmpDataset!=NULL)
{
GDALDriver * driver=NULL;
int index = maxNDVfile.ReverseFind('.');
if (index < 0)
return ;
if (index == maxNDVfile.GetLength()-1)
return ;
CString suffix = maxNDVfile.Right(maxNDVfile.GetLength()-1-index);
suffix.MakeLower();
if (suffix == "bmp")
driver = GetGDALDriverManager()->GetDriverByName("BMP");
else if (suffix == "jpg")
driver = GetGDALDriverManager()->GetDriverByName("JPEG");
else if (suffix == "tif")
driver = GetGDALDriverManager()->GetDriverByName("GTiff");
else if (suffix == "img")
driver = GetGDALDriverManager()->GetDriverByName("HFA");
else if (suffix == "bt")
driver = GetGDALDriverManager()->GetDriverByName("BT");
else if (suffix == "ecw")
driver = GetGDALDriverManager()->GetDriverByName("ECW");
else if (suffix == "fits")
driver = GetGDALDriverManager()->GetDriverByName("FITS");
else if (suffix == "gif")
driver = GetGDALDriverManager()->GetDriverByName("GIF");
else if (suffix == "hdf")
driver = GetGDALDriverManager()->GetDriverByName("HDF4");

else if (suffix == "hdr")
driver = GetGDALDriverManager()->GetDriverByName("EHdr");


int w=tmpDataset->GetRasterXSize();
int h=tmpDataset->GetRasterYSize();
GDALDataset *maxNDV=driver->Create(maxNDVfile,w,h,1,GDT_Float32,NULL);
int xOff=0;
int yOff=0;
int width=w;
int height=1;//一行一行地读取
vector bufs;
for(int i=0;i{
float *buf=new float[width*height];
bufs.push_back(buf);
buf=NULL;
}
float *newbuf=new float[width*height];
GDALRasterBand * newpoband=maxNDV->GetRasterBand(1);
for(int j=0;j{
for(int i=0;i{
GDALDataset *tmpDt=datasets[i];
GDALRasterBand * poband=tmpDt->GetRasterBand(1);
float *buf=bufs[i];
xOff=0;
yOff=j;
poband->RasterIO(GF_Read,xOff,yOff,width,height,buf,width,height,GDT_Float32,0,0);
buf=NULL;
tmpDt=NULL;//在后面再释放,因为很多个指针指向同一一段内存，不能随便释放内存哦
}
//////////
//在这可以开始运算咯
for(int k=0;k{
//下面这段代码以后要支持均值，极差，方差
for(int kk=0;kk{
float *buf=bufs[kk];
if(kk==0)//初始化
{
newbuf[k]=buf[k];
}
if(buf[k]>newbuf[k])//最大的,稍微改下就是最小值，
{
newbuf[k]=buf[k];
}
}
}
//////////写入数据
newpoband->RasterIO(GF_Write,xOff,yOff,width,height,newbuf,width,height,GDT_Float32,0,0);
}
delete newbuf;
newbuf=NULL;
for( i=0;i{
if(bufs[i]!=NULL)
delete bufs[i];
}
bufs.resize(0);
delete maxNDV;
maxNDV=NULL;
delete driver;
driver=NULL;
}
tmpDataset=NULL;
//释放掉内存
for( i=0;i{
if(datasets[i]!=NULL)
{
delete datasets[i];
datasets[i]=NULL;

}
}
datasets.resize(0);
}