Gdal remote sensing image reading and display-VC Environment

Gdal is a database for reading, writing, and reading data from grids and vectors. It has a huge application in the GIS industry. Remote sensing images are an important type of our spatial data, the following code reads and displays remote sensing data:

Char * szfilename = "K: \ provincial/municipal map \ new folder (2) \ fuzhoucity. TIF "; gdaldataset * podataset; // gdalallregister (); podataset = (gdaldataset *) gdalopen (szfilename, ga_readonly); If (podataset = NULL) {afxmessagebox (_ T ("file opening failed !!! "); Return;} gdalrasterband * poband1; // a remote sensing band gdalrasterband * poband2; gdalrasterband * poband3; int nbandcount = podataset-> getrastercount (); poband1 = podataset-> getrasterband (1); poband2 = podataset-> getrasterband (2); poband3 = podataset-> getrasterband (3 ); // obtain the size of the image display window getclientrect (& m_viewrect); int nimgsizex = podataset-> getrasterxsize (); int nimgsizey = podataset-> getrasterysize (); // obtain the coefficient of the affine transformation. Double adfgeotransform [6]; podataset-> getgeotransform (adfgeotransform); double right = adfgeotransform [0] + nimgsizex * adfgeotransform [1]; double Bottom = adfgeotransform [3] + nimgsizey * adfgeotransform [5]; int encrypted, encrypted; encrypted = nimgsizex; nbuffersizey = nimgsizey; int nscrrenwidth = m_viewrect.width (); int nscrrenheight = bytes (); // allocate memory byte * pafscanblock1, * pafscanblock2, * pafscanblock3, * templock1, * templock2, * templock3; pafscanblock1 = (byte *) for the data buffer zone *) cplmalloc (nscrrenwidth) * (nscrrenheight); pafscanblock2 = (byte *) cplmalloc (nscrrenwidth) * (nscrrenheight); substring = (byte *) cplmalloc (nscrrenwidth) * (nscrrenheight); templock1 = pafscanblock1; templock2 = pafscanblock2; templock3 = pafscanblock3; // read data poband1-> rasterio (gf_read, 0, 0, latency, latency, pafscanblock1, nscrrenwidth, nscrrenheight, gdt_byte, 0, 0); poband2-> rasterio (gf_read, 0, 0, average, average, pafscanblock2, nscrrenwidth, nscrrenheight, gdt_byte, 0, 0 ); poband3-> rasterio (gf_read, 0, 0, nbuffersizex, nbuffersizey, pafscanblock3, nscrrenwidth, nscrrenheight, gdt_byte, 0, 0 ); // display the image DWORD dwbytes = (nscrrenwidth * 24)/8 point by point in view; while (DWORD) dwbytes) % 4) {dwbytes ++ ;} byte * szbuffer = new byte [nscrrenheight * dwbytes]; memset (szbuffer, 0, nscrrenheight * dwbytes); byte * ptemp = szbuffer; cclientdc DC (this); int nindex = 0; for (INT I = 0; I <nscrrenheight; I ++) {for (Int J = 0; j <nscrrenwidth; j ++) {byte dn1 = * pafscanblock1; byte dn2 = * pafscanblock2; byte dn3 = * pafscanblock3; // It is first drawn to the memory DC and then to the DC dcmem of the device. setpixel (J, I, RGB (dn1, dn2, dn3); // display the pixel value pafscanblock1 ++; pafscanblock2 ++; pafscanblock3 ++ ;} szbuffer = ptemp + dwbytes * I;} PDC-> bitblt (0, 0, m_viewrect.width (), m_viewrect.height (), & dcmem, 0, 0, srccopy); cplfree (templock1 ); cplfree (templock2); cplfree (templock3 );

 

The following figure shows the effects of remote sensing images:

In this way, the display effect is the same as that opened by ArcGIS.