How to set some rgb transparent

Anonymous User

Original User: 674438511

Hi!

I'm looking for a code in c# that take a rasterlayer (.tif) and display it in my globecontrol with transparency where is some specific rgb,such as R0 G0 B0. I know i can add it to my globecontrol with this code

//////////
IRasterDataset pRasterdataset = pRasterworkspace.OpenRasterDataset(filename);   

IRaster pRaster = pRasterdataset.CreateDefaultRaster();
IRasterLayer pRasterlayer = new RasterLayerClass();
pRasterlayer.CreateFromRaster(pRaster);
ILayer pLayer = pRasterlayer as ILayer;
axGlobeControl1.Globe.AddLayerType(pLayer, esriGlobeLayerTypeFloating, false);
//////////

But how can i change some specific rgb(such as R0 G0 B0) of raster to transparency?

My guess:
///////
IRasterDataset pRasterdataset = pRasterworkspace.OpenRasterDataset(filename);
IRasterBandCollection rasterBands = (IRasterBandCollection)pRasterdataset;
IRasterBand rasterBand;
IRasterProps rasterProps;
           
rasterBand = rasterBands.Item(0);//band R
rasterProps = (IRasterProps)rasterBand;//now�?NoDataValue = 256 default value
rasterProps.NoDataValue = 0;
rasterBand = rasterBands.Item(1);//band G
rasterProps = (IRasterProps)rasterBand;//now�?NoDataValue = 256 default value
rasterProps.NoDataValue = 0;
rasterBand = rasterBands.Item(2);//band B
rasterProps = (IRasterProps)rasterBand;//now�?NoDataValue = 256 default value
rasterProps.NoDataValue = 0;

IRaster pRaster = pRasterdataset.CreateDefaultRaster();
IRasterProps propt = (IRasterProps)pRaster;//now�?NoDataValue = 0
IRasterLayer pRasterlayer = new RasterLayerClass();
pRasterlayer.CreateFromRaster(pRaster);
ILayer pLayer = pRasterlayer as ILayer;
axGlobeControl1.Globe.AddLayerType(pLayer, esriGlobeLayerTypeFloating, false);
///////

But, it doesn�??t work!

Now display�?(have black region)
[ATTACH=CONFIG]30108[/ATTACH]

I want�?(do not show black region)(yellow region is earth map)
[ATTACH=CONFIG]30109[/ATTACH]


Thanks

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YY

This old thread may help? http://forums.esri.com/Thread.asp?c=93&f=993&t=77571

Looks like it was figured out here... http://forums.esri.com/Thread.asp?c=93&f=992&t=77921

This is old code, not my code, I have not tested it, it's from the old forum post above... hope that helps...

'----------------change to stretched layer-------------------------
    Dim pStretchedRenderer As IRasterStretchColorRampRenderer
    Dim pRasterRendereer As IRasterRenderer
    Dim pRasterStretch As IRasterStretch
        Set pStretchedRenderer = New RasterStretchColorRampRenderer
        Set pRasterRendereer = pStretchedRenderer
        Set pRasterRendereer.Raster = pRLyr.Raster
        Set pRasterStretch = pStretchedRenderer
        pRasterStretch.BackgroundValues = 0
        pRasterStretch.Background = True
        Set pRLyr.Renderer = pStretchedRenderer
       
  pRLyr.Renderer.Update

  Set pStretchedRenderer = Nothing
  Set pRasterRendereer = Nothing
'----------------END change to stretched layer---------------------

Thanks!

I have tried your method and other methods in those URL. It does work when the tif image has only one band. But if the tif image has three bands(RGB), there will be some problem.

one band image original:
[ATTACH=CONFIG]30308[/ATTACH]

one band image after processing: (It works.)
[ATTACH=CONFIG]30309[/ATTACH]

three bands image original:
[ATTACH=CONFIG]30310[/ATTACH]

three bands image after processing: (It has problem. The RGB color is missing. Why?)
[ATTACH=CONFIG]30311[/ATTACH]

My code: (c#)
                    IRasterDataset pRasterdataset = pRasterworkspace.OpenRasterDataset(filename);
                    IRaster pRaster = pRasterdataset.CreateDefaultRaster();
                    IRasterLayer pRasterlayer = new RasterLayerClass();
                    pRasterlayer.CreateFromRaster(pRaster);

                    IRasterStretchColorRampRenderer pSR = new RasterStretchColorRampRenderer();
                    IRasterRenderer pRR = (IRasterRenderer)pSR;
                    pRR.Raster = pRasterlayer.Raster;
                    IRasterStretch pRS = (IRasterStretch)pSR;
                    //double[] bv = new double[3];
                    //bv[0] = 0.0;
                    //bv[1] = 0.0;
                    //bv[2] = 0.0;
                    //RgbColor c = new RgbColor();
                    //c.Red = 0;
                    //c.Green = 0;
                    //c.Blue = 0;
                    //c.Transparency = 0;
                    //c.NullColor = true;
                    //pRS.BackgroundColor = c;
                  
                    //pRS.StretchType = esriRasterStretchTypesEnum.esriRasterStretch_StandardDeviations;
                    //pRS.StandardDeviationsParam = 3;
                    pRS.set_BackgroundValues(0.0);
                    pRS.Background = true;
                    pRasterlayer.Renderer = (IRasterRenderer)pSR;
                    pRasterlayer.Renderer.Update();

                    ILayer pLayer = pRasterlayer as ILayer;
                    axGlobeControl1.Globe.AddLayerType(pLayer, esriGlobeLayerTypeFloating, false);


Thanks for your help~

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