4.[GDAL]4.影像的读取和显示2012-12-31

5.[GDAL]3.影像金字塔构建2012-12-22 6.[GDAL]2.读取栅格和矢量数据2012-12-21 7.[GDAL]读取HDF格式的calipso数据2015-04-15 8.[GDAL]写入shp2015-04-02 9.ArcEngine和GDAL读写栅格数据机制对比（二）—— IPixelBlock读写栅格2014-11-11 10.[GDAL]GEOS和Proj4编译2014-03-29 11.[GDAL]在三维场景中显示DEM2014-02-16 12.[转载]C#下使用GDAL将dem转换为灰度图2014-02-16 13.[GDAL]编译64位GDAL1.102014-02-15 14.C#+GDAL读写文件2013-11-11

RasterIO的用法参考：

在MFC项目中添加一个对话框DlgFastShow，添加一个按钮，在头文件中添加如下代码：

1 public:
2     GDALDataset* m_pDataset; 
3     double m_dScale;            //现有图框与图像的比值
4 
5     int m_iMinx;
6     int m_iMiny;
7     int m_iMaxx;
8     int m_iMaxy;
9     void ShowRaster();

在实现文件中添加如下代码：

  1 void DlgFastShow::OnBnClickedBtnOpenimage()
  2 {
  3     CFileDialog dlg(TRUE,NULL,NULL,OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT,_T("IMG影像文件(*.img)|*.img|TIFF影像文件(*.tif)|*.tif||"),AfxGetMainWnd());
  4     CString str;
  5     if (dlg.DoModal()==IDOK)
  6     {
  7         str=dlg.GetPathName();
  8         GDALAllRegister();  
  9         CPLSetConfigOption("GDAL_FILENAME_IS_UTF8","NO");
 10         const char* pszFile =(LPCTSTR)str;
 11          
 12         //使用只读方式打开图像   
 13         m_pDataset = (GDALDataset*)GDALOpen(pszFile,GA_ReadOnly); 
 14         if( m_pDataset == NULL )  
 15         {  
 16             CString ex;
 17             ex.AppendFormat("File: %s不能打开！\n",str);        
 18         }  
 19         double padfTransform[6] = {0.0};
 20         m_pDataset->GetGeoTransform(padfTransform);
 21         ShowRaster();
 22     }
 23 }
 24     void DlgFastShow::ShowRaster()
 25     {
 26         int iStartCol = 0;  
 27         int iStartRow = 0;      
 28         int dataWidth = m_pDataset->GetRasterXSize();//spinEndCol->value() - iStartCol;  
 29         int dataHeight =m_pDataset->GetRasterYSize();// spinEndRow->value() - iStartRow;  
 30         int dataBands =  m_pDataset->GetRasterCount(); 
 31         CString ex;
 32         ex.AppendFormat("行列数目: %d %d %d",dataWidth,dataHeight,dataBands);    
 33         int band_list[3] = {3,2,1};  
 34 
 35         m_dScale = dataHeight > dataWidth ? dataHeight : dataWidth;  
 36         int iViewHeight = 478;  
 37         m_dScale = iViewHeight/m_dScale;  
 38 
 39         int iSize = GDALGetDataTypeSize(GDT_Byte) / 8;//以字节为单位
 40         int iScaleWidth = static_cast<int>(dataWidth*m_dScale+0.5);  
 41         int iScaleHeight = static_cast<int>(dataHeight*m_dScale+0.5);  
 42         ex.AppendFormat("缓存数目: %d %d",iScaleWidth,iScaleHeight);    
 43         iScaleWidth = (iScaleWidth*8+31)/32*4;
 44         ex.AppendFormat("取整数目: %d ",iScaleWidth);    
 45         AfxMessageBox(ex);
 46         unsigned char* pBuffer = new unsigned char[iScaleWidth*iScaleHeight*3];  
 47         CPLErr err = m_pDataset->RasterIO(GF_Read, 0, 0,dataWidth, dataHeight, pBuffer, iScaleWidth, iScaleHeight,GDT_Byte, 3, band_list, iSize*3, iSize*iScaleWidth*3, iSize);   //读取3个波段的数据   
 48 
 49         unsigned char* pDataBuffer = NULL;  
 50         if (dataBands >=3 )  
 51         {  
 52             pDataBuffer = pBuffer;  
 53         }  
 54         else  
 55         {  
 56             pDataBuffer = new unsigned char[iScaleWidth*iScaleHeight*3];  
 57             for (int i=0; i<iScaleWidth*iScaleHeight*3; i++)  
 58                 pDataBuffer[i] = pBuffer[i/3];  
 59             delete []pBuffer;  
 60         }  
 61 
 62         /*CBitmap bitmap;            
 63         int flag=bitmap.CreateBitmap(iScaleWidth, iScaleHeight,1,24,pDataBuffer );*/
 64 //int flag=bitmap.CreateCompatibleBitmap(iScaleWidth, iScaleHeight,1,32,pDataBuffer );
 65         /*if (flag==0)
 66         {
 67             AfxMessageBox("创建位图失败！");
 68         }*/
 69         //HBITMAP hBmp;    // 保存CBitmap加载的位图的句柄      
 70         //hBmp = (HBITMAP)bitmap.GetSafeHandle();  // 获取bitmap加载位图的句柄            
 71          
 72         //picImage.SetBitmap(hBmp);  
 73         //CClientDC dc(this);
 74         //BITMAP bm;
 75         //bitmap.GetObject(sizeof    (BITMAP),&bm);
 76         //CDC dcMem;
 77         //dcMem.CreateCompatibleDC(&dc);
 78         //CBitmap *pOldbmp=dcMem.SelectObject(&bitmap);
 79         //CDC *pDC=&dc;
 80         //pDC->BitBlt(0,0,bm.bmWidth,bm.bmHeight,&dcMem,0,0,SRCCOPY);
 81         //dcMem.SelectObject(pOldbmp);
 82 
 83 
 84         CDC dc;
 85         CClientDC cdc(this);
 86 
 87         dc.Attach(cdc.m_hDC);
 88 
 89         CDC memDC;
 90         memDC.CreateCompatibleDC(&dc);
 91 
 92         CBitmap bmp;
 93         bmp.CreateCompatibleBitmap(&dc,500,500);
 94         memDC.SelectObject(&bmp);
 95 
 96         BITMAPINFO bmpInfo;
 97         bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
 98         bmpInfo.bmiHeader.biWidth = iScaleWidth;
 99         bmpInfo.bmiHeader.biHeight = -iScaleHeight;
100         //bmpInfo.bmiHeader.biWidth = 487;
101         //bmpInfo.bmiHeader.biHeight = -500;
102         bmpInfo.bmiHeader.biPlanes = 1;
103         bmpInfo.bmiHeader.biBitCount = 24;//24位色
104         bmpInfo.bmiHeader.biCompression = BI_RGB;
105         bmpInfo.bmiHeader.biSizeImage = 0;
106         bmpInfo.bmiHeader.biXPelsPerMeter = 3000;
107         bmpInfo.bmiHeader.biYPelsPerMeter = 3000;
108         bmpInfo.bmiHeader.biClrUsed = 0;
109         bmpInfo.bmiHeader.biClrImportant = 0;
110 
111         //每行字节数，4字节对齐
112         /*long nLnBytes = (487+3)/4*4*3;
113 
114         BYTE *pData = new BYTE[nLnBytes*500];
115         memset(pData,0,nLnBytes*500);
116         for(int i=10; i<90; i++)
117         {
118             pData[50*nLnBytes+i*3]=255;
119             pData[i*nLnBytes+50*3+2]=255;
120         }*/
121 
122         SetDIBits(dc.m_hDC,bmp,0,iScaleHeight,pDataBuffer,&bmpInfo,DIB_RGB_COLORS);
123         //delete []pData;
124         cdc.BitBlt(0,0,500,500,&memDC,0,0,SRCCOPY);
125         delete []pDataBuffer; 
126         
127     }