GetPixelData(Int32,Int32,IntPtr,Int32) Method

Copies the pixel data of the specified pixel into an unmanaged memory buffer.

Syntax

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public void GetPixelData( 
   int row,
   int column,
   IntPtr data,
   int dataSize
)

'Declaration
 
Public Overloads Sub GetPixelData( _
   ByVal row As Integer, _
   ByVal column As Integer, _
   ByVal data As IntPtr, _
   ByVal dataSize As Integer _
)

'Usage
 
Dim instance As RasterImage
Dim row As Integer
Dim column As Integer
Dim data As IntPtr
Dim dataSize As Integer
 
instance.GetPixelData(row, column, data, dataSize)

public void GetPixelData( 
   int row,
   int column,
   IntPtr data,
   int dataSize
)

 function Leadtools.RasterImage.GetPixelData(Int32,Int32,IntPtr,Int32)( 
   row ,
   column ,
   data ,
   dataSize 
)

public:
void GetPixelData( 
   int row,
   int column,
   IntPtr data,
   int dataSize
)

Parameters

row: The zero-based row number of the pixel.
column: The zero-based column number of the pixel
data: Pointer to unmanaged memory buffer to copy the pixel data to.
dataSize: Size of bytes the buffer in data.

Remarks

No transformations are performed on the pixel data.

The pixel data copied may represent an index into an images's palette, a grayscale value ((Document/Medical only), or red, green, and blue color values.

This method should be called only for 8, 16, 24, 32, 48 and 64-bit images. It works as follows:

For 8-bit images, this method will retrieve the palette index for the specified pixel.
For 16-bit images, this method will retrieve the 2-byte value that forms the pixel.
For 24-bit images, this method will retrieve the 3 bytes containing the pixel color. The Order determines whether the data is RGB or BGR.
For 32-bit images, this method will retrieve the 4 bytes containing the pixel color and alpha information. The first 3 bytes contain the pixel color. The The Order determines whether the data in the first 3 bytes is RGB or BGR. The 4th byte is the alpha channel information.
For 48-bit images, this method will retrieve the 6 bytes containing the pixel color. The Order determines whether the data is RGB or BGR. Each color component is stored as a 16-bit value, where 0 corresponds to black and 0xFFFF corresponds to full white.
For 64-bit images, this method will retrieve the 8 bytes containing the pixel color and alpha information. The Order determines whether the data in the first 6 bytes is RGB or BGR. Each color component is stored as a 16-bit value, where 0 corresponds to black and 0xFFFF corresponds to full white. The last two bytes contain the alpha information (also stored as a short value).

The minimum size of the returned byte array is calculated:

(BitsPerPixel + 7) / 8

You can use the SetPixelData(Int32,Int32,IntPtr,Int32) method to assign the returned value to another pixel.

This method uses image coordinates to specify the pixel. Therefore, you must account for the view perspective of the image. If you specify a pixel that is outside the image or outside the region (if the image has one), this method throws an exception.

The SetPixelData(Int32,Int32,IntPtr,Int32) method changes the data of the specified pixel.

For more information, refer to Introduction to Image Processing With LEADTOOLS.

For more information refer to Accounting for View Perspective.

Example

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Public Sub GetPixelDataExample()
      Dim codecs As RasterCodecs = New RasterCodecs()
      ' Load the image
      Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"))

      If image.BitsPerPixel = 24 Then
         Dim Data As Byte()
         Dim Value As Byte
         Dim Row As Integer = 10, Column As Integer = 20

         Data = image.GetPixelData(Row, Column)
         ' swap the R and B values
         Value = Data(0)
         Data(0) = Data(2)
         Data(2) = Value

         ' put back the transformed pixel
         image.SetPixelData(Row, Column, Data)
      End If

      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_GetPixelData.BMP"), RasterImageFormat.Bmp, 0)

      image.Dispose()
      codecs.Dispose()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

public void GetPixelDataExample()
   {
      RasterCodecs codecs = new RasterCodecs();
      // Load the image
      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"));

      if(image.BitsPerPixel == 24)
      {
         byte[] Data;
         byte Value;
         int Row = 10, Column = 20;

         Data = image.GetPixelData(Row, Column);
         // swap the R and B values
         Value = Data[0]; Data[0] = Data[2]; Data[2] = Value;

         // put back the transformed pixel
         image.SetPixelData(Row, Column, Data);
      }

      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_GetPixelData.BMP"), RasterImageFormat.Bmp, 0);

      image.Dispose();
      codecs.Dispose();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

RasterImageExamples.prototype.GetPixelDataExample = function () {
   Tools.SetLicense();
   with (Leadtools) {
      with (Leadtools.Codecs) {
         var codecs = new RasterCodecs();
         // Load the image
         var srcFileName = "Assets\\Image1.cmp";
         var image;

         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile))
         })
            .then(function (img) {
               image = img;

               if (image.bitsPerPixel === 24) {
                  var Data;
                  var Value;
                  var Row = 10, Column = 20;

                  Data = image.getPixelData(Row, Column);
                  // swap the R and B values
                  Value = Data[0]; Data[0] = Data[2]; Data[2] = Value;

                  // put back the transformed pixel
                  image.setPixelData(Row, Column, Data);
               }

               return Tools.AppLocalFolder().createFileAsync("IMAGE1_GetPixelData.BMP")
            })
            .then(function (saveFile) {
               var saveStream = LeadStreamFactory.create(saveFile);
               return codecs.saveAsync(image, saveStream, RasterImageFormat.bmp, 24)
            })
            .then(function () {

               image.close();
               codecs.close();
            });
      }
   }
}

[TestMethod]
public async Task GetPixelDataExample()
{
   RasterCodecs codecs = new RasterCodecs();
   // Load the image
   string srcFileName = @"Assets\Image1.cmp";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));
   if (image.BitsPerPixel == 24)
   {
      byte[] Data;
      byte Value;
      int Row = 10, Column = 20;

      Data = image.GetPixelData(Row, Column);
      // swap the R and B values
      Value = Data[0]; Data[0] = Data[2]; Data[2] = Value;

      // put back the transformed pixel
      image.SetPixelData(Row, Column, Data);
   }

   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync("IMAGE1_GetPixelData.BMP");
   ILeadStream saveStream = LeadStreamFactory.Create(saveFile);
   await codecs.SaveAsync(image, saveStream, RasterImageFormat.Bmp, 24);

   image.Dispose();
   codecs.Dispose();
}

public void GetPixelDataExample(RasterImage image, Stream destStream)
{
   if (image.BitsPerPixel == 24)
   {
      byte[] Data;
      byte Value;
      int Row = 10, Column = 20;
      Data = image.GetPixelData(Row, Column);
      // swap the R and B values
      Value = Data[0]; Data[0] = Data[2]; Data[2] = Value;

      // put back the transformed pixel
      image.SetPixelData(Row, Column, Data);
   }

   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, destStream, RasterImageFormat.Bmp, 0);

   image.Dispose();
}

Public Sub GetPixelDataExample(ByVal image As RasterImage, ByVal destStream As Stream)
   If image.BitsPerPixel = 24 Then
      Dim Data As Byte()
      Dim Value As Byte
      Dim Row As Integer = 10, Column As Integer = 20
      Data = image.GetPixelData(Row, Column)
      ' swap the R and B values
      Value = Data(0)
      Data(0) = Data(2)
      Data(2) = Value

      ' put back the transformed pixel
      image.SetPixelData(Row, Column, Data)
   End If

   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, destStream, RasterImageFormat.Bmp, 0)

   image.Dispose()
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

RasterImage Class
RasterImage Members
Overload List