利用GDAL库读取GeoTIFF文件

来源：互联网发布：釜山行影评知乎编辑：程序博客网时间：2024/05/18 20:31

经过一天的学习，终于对gdal库有所了解，下面是利用GDAL读取TIFF文件程序。

void CTestView::OnFileOpen()
{
// TODO: Add your command handler code here

     char szFilter[] = "GeoTiff (*.tif)|*.tif|All Files (*.*)|*.*||";
     CString filePath("");
     CFileDialog fileOpenDlg(TRUE, "tif", NULL,OFN_HIDEREADONLY,szFilter);
     if (fileOpenDlg.DoModal() == IDOK)
     {
          VERIFY(filePath = fileOpenDlg.GetPathName());
     }

     CString strFilePath(filePath);
    GDALDataset *poDataset;   //GDAL数据集
     GDALAllRegister();
    poDataset = (GDALDataset *) GDALOpen(strFilePath, GA_ReadOnly );
    if( poDataset == NULL )
     {
        AfxMessageBox("文件打开失败!!!");
        return;
     }

   GDALRasterBand *poBand1;   //遥感的一个波段
    GDALRasterBand *poBand2;
   GDALRasterBand *poBand3;
    int nBandCount;
   nBandCount=poDataset->GetRasterCount();
    poBand1=poDataset->GetRasterBand(1);
    poBand2=poDataset->GetRasterBand(2);
   poBand3=poDataset->GetRasterBand(3);

//获取图像的尺寸
//获取图像窗口尺寸
CRect rect;
GetClientRect(rect);

int nImgSizeX=poDataset->GetRasterXSize();
int nImgSizeY=poDataset->GetRasterYSize();
int nBufferSizeX,nBufferSizeY;
nBufferSizeY=rect.Height();
float m_fXYRation;
m_fXYRation = (float)nImgSizeY/(float)nImgSizeX;
nBufferSizeX = (int)(m_fXYRation*(float)nBufferSizeY);

BYTE *pafScanblock1;
BYTE *pafScanblock2;
BYTE *pafScanblock3;
pafScanblock1 = (BYTE *) CPLMalloc(sizeof(BYTE)*(nBufferSizeX)*(nBufferSizeY));
pafScanblock2 = (BYTE *) CPLMalloc(sizeof(BYTE)*(nBufferSizeX)*(nBufferSizeY));
   pafScanblock3 = (BYTE *) CPLMalloc(sizeof(BYTE)*(nBufferSizeX)*(nBufferSizeY));
poBand1->RasterIO( GF_Read, 0, 0,nBufferSizeX,nBufferSizeY,
   pafScanblock1,nBufferSizeX,nBufferSizeY, GDT_Byte,0, 0 );
poBand2->RasterIO( GF_Read, 0, 0,nBufferSizeX,nBufferSizeY,
   pafScanblock2,nBufferSizeX,nBufferSizeY, GDT_Byte,0, 0 );
poBand3->RasterIO( GF_Read, 0, 0,nBufferSizeX,nBufferSizeY,
   pafScanblock3,nBufferSizeX,nBufferSizeY, GDT_Byte,0, 0 );

   //在View逐点显示图像
for (int i=0;i<nBufferSizeY;i++)
for (int j=0;j<nBufferSizeX;j++)
  {
      BYTE dn1=*pafScanblock1;
      BYTE dn2=*pafScanblock2;
       BYTE dn3=*pafScanblock3;
       CClientDC dc(this);
      dc.SetPixel(j,i,RGB(dn1,dn2,dn3));

       pafScanblock1++;
   pafScanblock2++;
      pafScanblock3++;
  }

}