# DEM file loading with MapWinGIS

**URL:** <https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634>\
**Category:** MapWinGIS\
**Created:** [September 13, 2023, 6:03am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634 "2023-09-13T06:03:52Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 13, 2023, 6:03am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/1 "2023-09-13T06:03:52Z")

</div>

Hellow. everyone!  
I’m new to GIS and MapWinGIS. So I need your help.  
I want to load a DEM file in winform.  
So, I get a DEM file(file’s extentions is \*.img) from [http://data.nsdi.go.kr](http://data.nsdi.go.kr)\>dataset…  
and I can see black and white image with QGIS desktop.

Please let me know what kind of libraries or variables are used to load \*.img file.  
Thanks…!!

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<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 13, 2023, 7:58am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/2 "2023-09-13T07:58:22Z")

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I use  
IGdalDataset dataset;  
IGdalDriver driver;  
and, file open…

```
        OpenFileDialog ofd = new OpenFileDialog
        {
            DefaultExt = "img",
            Filter = "ERDAS Image Files|*.img"
        };

        if (ofd.ShowDialog() == DialogResult.OK)
       {
            dataset = new GdalDataset();
            dataset.Open(ofd.FileName, true);
            driver = dataset.Driver;

            textBox1.AppendText("File Name : " + ofd.FileName + "\r\n");

            int subsetcnt = dataset.SubDatasetCount;
            textBox1.AppendText("SubDataSet Count : " + subsetcnt.ToString() + "\r\n");

            bool israster = driver.IsRaster;
            textBox1.AppendText("Is Raster? : " + israster.ToString() + "\r\n");

            bool isvector = driver.IsVector;
            textBox1.AppendText("Is Vector? : " + isvector.ToString() + "\r\n");

            int metedatacnt = driver.MetadataCount;
            textBox1.AppendText("Metadata Count " + metedatacnt.ToString() + "\r\n");

            string name = driver.Name;
            textBox1.AppendText("GDAL Driver Name : " + name + "\r\n");

            string mdata;
            for(int i = 0; i< driver.MetadataCount ; i++)
            {
                mdata = driver.MetadataItem[i];
                textBox1.AppendText(string.Format("Driver.MetadataItem[{0}] : ", i) + mdata + "\r\n");
            }
      }

```

So, I can read some data of \*.img file.

SubDataSet Count : 0  
Is Raster? : True  
Is Vector? : False  
Metadata Count 11  
GDAL Driver Name : HFA  
Driver.MetadataItem[0] : DCAP\_CREATE=YES  
Driver.MetadataItem[1] : DCAP\_CREATECOPY=YES  
Driver.MetadataItem[2] : DCAP\_OPEN=YES  
Driver.MetadataItem[3] : DCAP\_RASTER=YES  
Driver.MetadataItem[4] : DCAP\_VIRTUALIO=YES  
Driver.MetadataItem[5] : DMD\_CREATIONDATATYPES=Byte Int16 UInt16 Int32 UInt32 Float32 Float64 CFloat32 CFloat64  
Driver.MetadataItem[6] : DMD\_CREATIONOPTIONLIST=   
Driver.MetadataItem[7] : DMD\_EXTENSION=img  
Driver.MetadataItem[8] : DMD\_EXTENSIONS=img  
Driver.MetadataItem[9] : DMD\_HELPTOPIC=frmt\_hfa.html  
Driver.MetadataItem[10] : DMD\_LONGNAME=Erdas Imagine Images (.img)

Still, I don’t know where are DEM datas…

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<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 14, 2023, 2:33am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/3 "2023-09-14T02:33:23Z")

</div>

I tried others…  
GdalDriverManager manager = new GdalDriverManager();  
textBox1.AppendText(“GDAL Driver Count : " + manager.DriverCount.ToString() + “\r\n”);  
for (int i = 0; i \< manager.DriverCount; i++)  
{  
textBox1.AppendText(string.Format(”[{0}] : ", i) + manager.Driver[i].Name + “\r\n”);  
}

I found 214 drivers in 35913.img file

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<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 21, 2023, 2:42am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/4 "2023-09-21T02:42:28Z")

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I tried other one.

layerHandler = axMap1.AddLayerFromFilename(filename, tkFileOpenStrategy.fosAutoDetect, true);

then raster image is loaded to axMap1.

Let me know how to get height data(matrix) from loaded layer.  
So, I want to make a profile of path[point to point]

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<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 21, 2023, 5:27am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/5 "2023-09-21T05:27:53Z")

</div>

I tried other one…

demlayerHandler = axMap1.AddLayerFromFilename(filename, tkFileOpenStrategy.fosAutoDetect, true);  
object obj = axMap1.get\_GetObject(demlayerHandler);

Load the added layer to object.  
In Debugging, obj have dynamic views…

Please let me know, how to assign the obj’s values to float?

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<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 22, 2023, 8:22am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/6 "2023-09-22T08:22:32Z")

</div>

Finally, I get Digital Elevation datas from \*\*\*.img file.

1. Make a axMap1 at form

2. Load a file(in my case, get \*.img files from [수치표고모델(DEM)\_90M - 오픈마켓](http://data.nsdi.go.kr/dataset/20001))

3. Get Image from layer

4. Get rasterband

5. Read digital elevation values

6. Use the data to others…

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<div class="post-metadata">

**Author:** ![thesorus](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@thesorus](https://mapwindow.discourse.group/u/thesorus)\
**Post date:** [September 27, 2023, 12:59am UTC](https://mapwindow.discourse.group/t/dem-file-loading-with-mapwingis/1634/7 "2023-09-27T00:59:30Z")

</div>

![image](https://global.discourse-cdn.com/free1/uploads/mapwindow1/original/1X/1a5aa1d6e95edc180e0a717618fc229930d8f518.png)

Finally, I make a Geo-profile…

If someone knows other beautiful way, let me know.  
Thanks…