<DIV>Thk u&nbsp; for your answer.</DIV>

<DIV>1.I have change the following code:</DIV>

<DIV>for(int i=1;i&lt;=nY;i++)</DIV>

<DIV>to</DIV>

<DIV>for(int i=0;i&lt;nY;i++)</DIV>

<DIV>but the problem still exists(CPU is very busy).</DIV>

<DIV>2.the function GDALDatasetCopyWholeRaster can not satisfy me,for I want&nbsp;to do the&nbsp;follow things:</DIV>

<DIV>read Srcband1,Srcband2,</DIV>

<DIV>Dstband1=Srcband1&nbsp;+Srcband2;</DIV>

<DIV>that is,I want to do some computing after readding data.</DIV>

<DIV>Kind regards.<BR></DIV>

<DIV></DIV><BR><PRE><BR>&gt;The&nbsp;RasterIO&nbsp;parameters&nbsp;are&nbsp;not&nbsp;correct.

&gt;

&gt;Try&nbsp;instead&nbsp;:

&gt;&nbsp;poSrcBand-&gt;RasterIO(GF_Read,0,i,nX,1,pafScanline,nX,1,GDT_Float32,0,0);

&gt;&nbsp;poDstBand-&gt;RasterIO(GF_Write,0,i,nX,1,pafScanline,nX,1,GDT_Float32,0,0);

&gt;

&gt;The&nbsp;'for(int&nbsp;i=1;i&lt;nY;i++)'&nbsp;loop&nbsp;is&nbsp;not&nbsp;correct.&nbsp;The&nbsp;starting&nbsp;value&nbsp;of&nbsp;i&nbsp;

&gt;should&nbsp;be&nbsp;0.

&gt;

&gt;Ther's&nbsp;also&nbsp;a&nbsp;leak&nbsp;of&nbsp;the&nbsp;*pafScanline&nbsp;buffer.

&gt;

&gt;But&nbsp;if&nbsp;I&nbsp;were&nbsp;you,&nbsp;I'd&nbsp;use&nbsp;the&nbsp;following&nbsp;function&nbsp;to&nbsp;do&nbsp;the&nbsp;copy&nbsp;of&nbsp;the&nbsp;

&gt;imagery&nbsp;:

&gt;

&gt;CPLErr&nbsp;CPL_DLL&nbsp;CPL_STDCALL&nbsp;GDALDatasetCopyWholeRaster(

&gt;&nbsp;&nbsp;&nbsp;&nbsp;GDALDatasetH&nbsp;hSrcDS,&nbsp;GDALDatasetH&nbsp;hDstDS,&nbsp;char&nbsp;**papszOptions,&nbsp;

&gt;&nbsp;&nbsp;&nbsp;&nbsp;GDALProgressFunc&nbsp;pfnProgress,&nbsp;void&nbsp;*pProgressData&nbsp;);

&gt;

&gt;Le&nbsp;Sunday&nbsp;11&nbsp;April&nbsp;2010&nbsp;08:32:51&nbsp;weixj2003ld,&nbsp;vous&nbsp;avez&nbsp;écrit&nbsp;:

&gt;&gt;&nbsp;I&nbsp;use&nbsp;the&nbsp;following&nbsp;code&nbsp;to&nbsp;read&nbsp;data&nbsp;from&nbsp;a&nbsp;geotiff&nbsp;file&nbsp;and&nbsp;write&nbsp;it&nbsp;into

&gt;&gt;&nbsp;a&nbsp;new&nbsp;one.the&nbsp;bands&nbsp;number&nbsp;is&nbsp;6;&nbsp;...

&gt;&gt;&nbsp;GDALDataset&nbsp;*poSrcDS,*poDstDS;//poSrcDs:the&nbsp;source&nbsp;file,poDstDS:the&nbsp;goal

&gt;&gt;&nbsp;source&nbsp;GDALRasterBand&nbsp;*poSrcBand,*poDstBand;//poSrcBand:the&nbsp;source

&gt;&gt;&nbsp;band,poDstBand:the&nbsp;goal&nbsp;band&nbsp;GDALDriver&nbsp;*poDstDriver;

&gt;&gt;&nbsp;double&nbsp;*m_AdGeoTransform=new&nbsp;double[6];

&gt;&gt;

&gt;&gt;&nbsp;...

&gt;&gt;&nbsp;poDstDriver=GetGDALDriverManager()-&gt;GetDriverByName(poSrcDS-&gt;GetDriver()-&gt;G

&gt;&gt;etDescrition());

&gt;&gt;&nbsp;poDstDS=poDstDriver-&gt;create(DstFilename,nX,nY,6,GDT_Float32,NULL);

&gt;&gt;&nbsp;poSrcDS-&gt;GetGeoTransform(m_AdGeoTransform)

&gt;&gt;&nbsp;poDstDS-&gt;SetGeoTransform(m_AdGeoTransform);

&gt;&gt;&nbsp;poDstDS-&gt;SetProjection(poSrcDS-&gt;GetProjectionRef());

&gt;&gt;

&gt;&gt;&nbsp;for(int&nbsp;iBand=0;iBand&lt;6;iBand++)

&gt;&gt;&nbsp;{

&gt;&gt;&nbsp;&nbsp;&nbsp;&nbsp;poSrcBand=poSrcDS-&gt;GetRaserBand(iBand+1);

&gt;&gt;&nbsp;&nbsp;&nbsp;poDstBand=poDstDS-&gt;GetRaserBand(iBand+1);

&gt;&gt;&nbsp;&nbsp;&nbsp;float&nbsp;*pafScanline;

&gt;&gt;&nbsp;&nbsp;&nbsp;pafScanline=(float&nbsp;*)CPLMalloc(sizeof(float)*nX;

&gt;&gt;&nbsp;&nbsp;&nbsp;for(int&nbsp;i=1;i&lt;nY;i++)

&gt;&gt;&nbsp;&nbsp;&nbsp;{

&gt;&gt;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

&gt;&gt;&nbsp;poSrcBand-&gt;RasterIO(GF_Read,0,0,nX,i,pafScanline,nX,1,GDT_Float32,0,0);

&gt;&gt;&nbsp;poDstBand-&gt;RasterIO(GF_Write,0,0,nX,i,pafScanline,nX,1,GDT_Float32,0,0);//I

&gt;&gt;f&nbsp;I&nbsp;comment&nbsp;this&nbsp;code,the&nbsp;program&nbsp;will&nbsp;be&nbsp;ok.&nbsp;}

&gt;&gt;&nbsp;}

&gt;&gt;&nbsp;GDALClose((GDALDatasetH)poDstDS);

&gt;&gt;

&gt;&gt;&nbsp;When&nbsp;I&nbsp;run&nbsp;my&nbsp;program,CPU&nbsp;is&nbsp;very&nbsp;alway&nbsp;busy,and&nbsp;the&nbsp;program&nbsp;is

&gt;&gt;&nbsp;blocked,why?

&gt;

&gt;

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