关于图框裁剪

[已解决] 关于图框裁剪

有若干不同图幅的JPG格式影像，为接边方便有重叠，现需要吧重复的外围部分裁剪掉，如何处理，谁做过的能不能给点代码或思路提示，谢过。

我参考 lsbocai 2008-5-28  影像数据裁切和保存 一文
但是在保存的时候 不管是直接保存成图像 还是保存到数据库 都有问题
请高手指点
//影像裁切
IGeometry clipGeo = axMapControl1.TrackPolygon();  //
ILayer layer = axMapControl1.get_Layer(i);   //要裁切的影像图层
IRasterLayer pRasterLayer = layer as IRasterLayer;
IRaster pRaster = pRasterLayer.Raster;
IRasterProps pProps = pRaster as IRasterProps;
object cellSizeProvider = pProps.MeanCellSize().X;
IGeoDataset pInputDataset = pRaster as IGeoDataset;
IExtractionOp pExtractionOp = new RasterExtractionOpClass();
IRasterAnalysisEnvironment pRasterAnaEnvir = pExtractionOp as IRasterAnalysisEnvironment;
pRasterAnaEnvir.SetCellSize(esriRasterEnvSettingEnum.esriRasterEnvValue, ref cellSizeProvider);
object extentProvider = clipGeo.Envelope;
object snapRasterData = Type.Missing;
pRasterAnaEnvir.SetExtent(esriRasterEnvSettingEnum.esriRasterEnvValue, ref extentProvider, ref snapRasterData);
IGeoDataset pOutputDataset = pExtractionOp.Polygon(pInputDataset, clipGeo as IPolygon, true);
IRaster clipRaster;  //裁切后得到的IRaster
if (pOutputDataset is IRasterLayer)
{
    IRasterLayer rasterLayer = pOutputDataset as IRasterLayer;
    clipRaster = rasterLayer.Raster;
}
else if (pOutputDataset is IRasterDataset)
{
    IRasterDataset rasterDataset = pOutputDataset as IRasterDataset;
    clipRaster = rasterDataset.CreateDefaultRaster();
}
else if (pOutputDataset is IRaster)
{
    clipRaster = pOutputDataset as IRaster;
}
else
{
    return;
}

//保存裁切后得到的clipRaster

//如果直接保存为img影像文件
IWorkspaceFactory pWKSF = new RasterWorkspaceFactoryClass();
IWorkspace pWorkspace = pWKSF.OpenFromFile(@"C:\temp", 0);
ISaveAs pSaveAs = clipRaster as ISaveAs;
pSaveAs.SaveAs("test.img", pWorkspace, "IMAGINE Image");

//如果保存在mdb中
IRasterStorageDef pRasterStorageDef = new RasterStorageDefClass();
pRasterStorageDef.CompressionType = esriRasterCompressionType.esriRasterCompressionJPEG2000;
pRasterStorageDef.CompressionQuality = 50;
pRasterStorageDef.TileHeight = 128;
pRasterStorageDef.TileWidth = 128;
IWorkspaceFactory pWKSF = new AccessWorkspaceFactoryClass();
IWorkspace pWorkspace = pWKSF.OpenFromFile(@"C:\temp\test.mdb", 0);
ISaveAs2 pSaveAs = clipRaster as ISaveAs2;
pSaveAs.SaveAsRasterDataset("test", pWorkspace, "gdb", pRasterStorageDef);

 我又换一种方法来裁剪，通过四角坐标创建多边形来裁剪，可以裁剪也可以保存但是过程中会出现错误提示 尝试读取或写入受保护的内存。这通常指示其他内存已损坏。
整个代码如下 ， 麻烦指点下
private void clipToolStripMenuItem_Click(object sender, EventArgs e)
        {
            BeginClip();
        }
        public IRaster ClipRasterByPolygon(IGeoDataset pInGeoDataset, IPolygon pPolygon)
        {

            IRaster pRaster =null;
            
            if (pInGeoDataset is IRasterLayer)
            {
                IRasterLayer rasterLayer = pInGeoDataset as IRasterLayer;
                pRaster = rasterLayer.Raster;

            }
            else if (pInGeoDataset is IRasterDataset)
            {
                IRasterDataset rasterDataset = pInGeoDataset as IRasterDataset;
                pRaster = rasterDataset.CreateDefaultRaster();
            }
            else if (pInGeoDataset is IRaster)
            {
                pRaster = pInGeoDataset as IRaster;
            }
            else
            {
                return null;
            }
            IGeoDataset pInputDataset = pRaster as IGeoDataset;
            IExtractionOp pExtractionOp = new RasterExtractionOpClass();
            IRasterAnalysisEnvironment pRasterAnalysisEnvironment = pExtractionOp as IRasterAnalysisEnvironment;
            object cellSizeProvider = GetRasterCellSize(pRaster);
            pRasterAnalysisEnvironment.SetCellSize(esriRasterEnvSettingEnum.esriRasterEnvValue, ref cellSizeProvider);
            object extentProvider = pPolygon.Envelope;
            object snapRasterData = Type.Missing;
            pRasterAnalysisEnvironment.SetExtent(esriRasterEnvSettingEnum.esriRasterEnvValue, ref extentProvider, ref snapRasterData);
            IGeoDataset pOutputDataset = pExtractionOp.Polygon(pInputDataset, pPolygon, true);
            IRaster clipRaster = pOutputDataset as IRaster;
            return clipRaster;

        }
        public double GetRasterCellSize(IRaster pRaster)//获取RasterCellSize
        {
            IRasterProps pProps = pRaster as IRasterProps;
            return pProps.MeanCellSize().X;
        }
        public void BeginClip()
        {
            try
            {
                ILayer layer = axMapControl1.get_Layer(0);   //要裁切的影像图层
                IRasterLayer pRasterLayer = layer as IRasterLayer;
                //IRaster pRaster = pRasterLayer.Raster;
                IGeoDataset pGeoDataSet;
                pGeoDataSet = layer as IGeoDataset;

                double StartX, StartY, dx, dy, Xmin, Ymin, Dx, Dy;
                //dx = 600; dy = 500; Dx = 3922; Dy = 2680;
                dx = 50; dy = 50; Dx = 600; Dy = 600;
                Xmin = pRasterLayer.VisibleExtent.XMin;
                Ymin = pRasterLayer.VisibleExtent.YMin;
                StartX = Xmin + dx;
                StartY = Ymin + dy;
                IRaster pRaster;
                IPolygon pPolygon = CreatePolygon(StartX, StartY, Dx, Dy);
                pRaster = ClipRasterByPolygon(pGeoDataSet, pPolygon);
                //pRasterLayer.CreateFromRaster(pRaster);

                //axMapControl1.AddLayer(pRasterLayer);

                //保存影像文件
                IWorkspaceFactory pWKSF = new RasterWorkspaceFactoryClass();//
                IWorkspace pWorkspace = pWKSF.OpenFromFile(@"E:\\work\\raster", 0);
                ISaveAs pSaveAs = pRaster as ISaveAs;
                pSaveAs.SaveAs("test02.jpg", pWorkspace, "JPG");

                pRasterLayer.CreateFromRaster(pRaster);

                axMapControl1.AddLayer(pRasterLayer);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            ////保存到mdb
            //IRasterStorageDef pRasterStorageDef = new RasterStorageDefClass();
            //pRasterStorageDef.CompressionType = esriRasterCompressionType.esriRasterCompressionJPEG2000;
            //pRasterStorageDef.CompressionQuality = 50;
            //pRasterStorageDef.TileHeight = 128;
            //pRasterStorageDef.TileWidth = 128;
            //IWorkspaceFactory pWKSF = new ESRI.ArcGIS.DataSourcesGDB.AccessWorkspaceFactoryClass();
            //IWorkspace pWorkspace = pWKSF.OpenFromFile(@"e:\work\db2.mdb", 0);
            ////IWorkspace pWorkspace = (IWorkspace)OpenFileGDBWorkspace(@"e:\work\db2.mdb");

            //ISaveAs2 pSaveAs = clipRaster as ISaveAs2;
            //pSaveAs.SaveAsRasterDataset("compressedRaster", pWorkspace, "GDB", pRasterStorageDef);
            

        }
        public IPolygon CreatePolygon(double StartX, double StartY, double dx, double dy)
        {
            IPointCollection4 pPntsCol;
            IPoint pLeftBottomPoint, pLeftTopPoint, pRightTopPoint, pRightBottomPoint;
            pPntsCol = new PolygonClass();

            pLeftBottomPoint = new PointClass();
            pLeftBottomPoint.X = StartX;
            pLeftBottomPoint.Y = StartY;
            object missing = Type.Missing;
            pPntsCol.AddPoint(pLeftBottomPoint, ref missing, ref missing);

            pLeftTopPoint = new PointClass();
            pLeftTopPoint.X = StartX;
            pLeftTopPoint.Y = StartY + dy;
            pPntsCol.AddPoint(pLeftTopPoint, ref missing, ref missing);

            pRightTopPoint = new PointClass();
            pRightTopPoint.X = StartX + dx;
            pRightTopPoint.Y = StartY + dy;
            pPntsCol.AddPoint(pRightTopPoint, ref missing, ref missing);


            pRightBottomPoint = new PointClass();
            pRightBottomPoint.X = StartX + dx;
            pRightBottomPoint.Y = StartY;
            pPntsCol.AddPoint(pRightBottomPoint, ref missing, ref missing);

            IPolygon4 pPoly = pPntsCol as IPolygon4;
            pPoly.Close();
            
            IMap pMap = axMapControl1.Map;
            ISpatialReference pSRMap = pMap.SpatialReference;// as ISpatialReference;
            pPoly.SpatialReference = pSRMap;
            
            IPolygon pReturnPolygon = pPoly as IPolygon;
            return pReturnPolygon;

        }