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GetRow(Int32,Byte[],Int32,Int32) Method
See Also 
Leadtools Namespace > RasterImage Class > GetRow Method : GetRow(Int32,Byte[],Int32,Int32) Method



row
The number of the row to retrieve. The first row is 0, and the last row is 1 less than the image height.
buffer
Buffer to hold the image data that this method gets. The size of this buffer must be large enough to hold the image data.
bufferIndex
The zero-based index into the buffer where the get operation should start.
bufferCount

The number of bytes in the row to retrieve. To get a full row, use the value in the BytesPerLine property

When getting less than full row, you must consider the bits per pixel. For a 1-bit image, each byte represents 8 pixels. For a 4-bit image, each byte represents 2 pixels. For an 8-bit image, each byte represents 1 pixel. For a 16-bit image, every 2 bytes represents one pixel. For 24-bit images, every three bytes represents one pixel. For a 32-bit image, every four bytes represents one pixel. For 48-bit images, every six bytes represents one pixel. For 64-bit images, every eight bytes represents one pixel.

You can use the BitsPerPixel property with integer math to calculate the number of bytes needed for a particular number of pixels. For example:

            NumberOfBytes = (Image.BitsPerPixel * NumberOfPixels) / 8;
            if((Image.BitsPerPixel * NumberOfPixels) % 8)
               NumberOfBytes = NumberOfBytes + 1; // Round up if necessary for a 1- or 4-bit image

row
The number of the row to retrieve. The first row is 0, and the last row is 1 less than the image height.
buffer
Buffer to hold the image data that this method gets. The size of this buffer must be large enough to hold the image data.
bufferIndex
The zero-based index into the buffer where the get operation should start.
bufferCount

The number of bytes in the row to retrieve. To get a full row, use the value in the BytesPerLine property

When getting less than full row, you must consider the bits per pixel. For a 1-bit image, each byte represents 8 pixels. For a 4-bit image, each byte represents 2 pixels. For an 8-bit image, each byte represents 1 pixel. For a 16-bit image, every 2 bytes represents one pixel. For 24-bit images, every three bytes represents one pixel. For a 32-bit image, every four bytes represents one pixel. For 48-bit images, every six bytes represents one pixel. For 64-bit images, every eight bytes represents one pixel.

You can use the BitsPerPixel property with integer math to calculate the number of bytes needed for a particular number of pixels. For example:

            NumberOfBytes = (Image.BitsPerPixel * NumberOfPixels) / 8;
            if((Image.BitsPerPixel * NumberOfPixels) % 8)
               NumberOfBytes = NumberOfBytes + 1; // Round up if necessary for a 1- or 4-bit image

Retrieves a row or more of image data from this RasterImage into a managed memory buffer. Supported in Silverlight, Windows Phone 7

Syntax

Visual Basic (Declaration) 
Overloads Public Function GetRow( _
   ByVal row As Integer, _
   ByVal buffer() As Byte, _
   ByVal bufferIndex As Integer, _
   ByVal bufferCount As Integer _
) As Integer
Visual Basic (Usage)Copy Code
Dim instance As RasterImage
Dim row As Integer
Dim buffer() As Byte
Dim bufferIndex As Integer
Dim bufferCount As Integer
Dim value As Integer
 
value = instance.GetRow(row, buffer, bufferIndex, bufferCount)
C# 
public int GetRow( 
   int row,
   byte[] buffer,
   int bufferIndex,
   int bufferCount
)
C++/CLI 
public:
int GetRow( 
   int row,
   array<byte>^ buffer,
   int bufferIndex,
   int bufferCount
)

Parameters

row
The number of the row to retrieve. The first row is 0, and the last row is 1 less than the image height.
buffer
Buffer to hold the image data that this method gets. The size of this buffer must be large enough to hold the image data.
bufferIndex
The zero-based index into the buffer where the get operation should start.
bufferCount

The number of bytes in the row to retrieve. To get a full row, use the value in the BytesPerLine property

When getting less than full row, you must consider the bits per pixel. For a 1-bit image, each byte represents 8 pixels. For a 4-bit image, each byte represents 2 pixels. For an 8-bit image, each byte represents 1 pixel. For a 16-bit image, every 2 bytes represents one pixel. For 24-bit images, every three bytes represents one pixel. For a 32-bit image, every four bytes represents one pixel. For 48-bit images, every six bytes represents one pixel. For 64-bit images, every eight bytes represents one pixel.

You can use the BitsPerPixel property with integer math to calculate the number of bytes needed for a particular number of pixels. For example:

            NumberOfBytes = (Image.BitsPerPixel * NumberOfPixels) / 8;
            if((Image.BitsPerPixel * NumberOfPixels) % 8)
               NumberOfBytes = NumberOfBytes + 1; // Round up if necessary for a 1- or 4-bit image

Return Value

The number of bytes copied.

Example

This example uses Get/SetRow to flip the image data.

Visual BasicCopy Code
Public Sub GetRowTest()
      Dim codecs As RasterCodecs = New RasterCodecs()
      Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"))

      Dim row1 As Byte() = New Byte(image.BytesPerLine - 1) {}
      Dim row2 As Byte() = New Byte(image.BytesPerLine - 1) {}

      If image.IsGlobalMemory Then
         image.Access()
      End If
      Dim y As Integer = 0
      Do While y < image.Height \ 2
         image.GetRow(y, row1, 0, row1.Length)
         image.GetRow(image.Height - y - 1, row2, 0, row2.Length)

         image.SetRow(y, row2, 0, row2.Length)
         image.SetRow(image.Height - y - 1, row1, 0, row1.Length)
         y += 1
      Loop
      If image.IsGlobalMemory Then
         image.Release()
      End If

      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_getrow.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
C#Copy Code
public void GetRowTest()
   {
      RasterCodecs codecs = new RasterCodecs();
      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"));

      byte[] row1 = new byte[image.BytesPerLine];
      byte[] row2 = new byte[image.BytesPerLine];

      if(image.IsGlobalMemory)
         image.Access();
      for(int y = 0; y < image.Height / 2; y++)
      {
         image.GetRow(y, row1, 0, row1.Length);
         image.GetRow(image.Height - y - 1, row2, 0, row2.Length);

         image.SetRow(y, row2, 0, row2.Length);
         image.SetRow(image.Height - y - 1, row1, 0, row1.Length);
      }
      if(image.IsGlobalMemory)
         image.Release();

      codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_getrow.BMP"), RasterImageFormat.Bmp, 0);

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

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
SilverlightCSharpCopy Code
public void GetRowTest(RasterImage image, Stream destStream)
{
   byte[] row1 = new byte[image.BytesPerLine];
   byte[] row2 = new byte[image.BytesPerLine];
   if (image.IsGlobalMemory)
      image.Access();
   for (int y = 0; y < image.Height / 2; y++)
   {
      image.GetRow(y, row1, 0, row1.Length);
      image.GetRow(image.Height - y - 1, row2, 0, row2.Length);

      image.SetRow(y, row2, 0, row2.Length);
      image.SetRow(image.Height - y - 1, row1, 0, row1.Length);
   }
   if (image.IsGlobalMemory)
      image.Release();

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

   image.Dispose();
}
SilverlightVBCopy Code
Public Sub GetRowTest(ByVal image As RasterImage, ByVal destStream As Stream)
   Dim row1 As Byte() = New Byte(image.BytesPerLine - 1){}
   Dim row2 As Byte() = New Byte(image.BytesPerLine - 1){}
   If image.IsGlobalMemory Then
      image.Access()
   End If
   Dim y As Integer = 0
   Do While y < image.Height / 2
      image.GetRow(y, row1, 0, row1.Length)
      image.GetRow(image.Height - y - 1, row2, 0, row2.Length)

      image.SetRow(y, row2, 0, row2.Length)
      image.SetRow(image.Height - y - 1, row1, 0, row1.Length)
      y += 1
   Loop
   If image.IsGlobalMemory Then
      image.Release()
   End If

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

   image.Dispose()
End Sub

Remarks

This method copies image data from the RasterImage object to a buffer that you specify. The data is copied exactly as it is stored in the image. The image memory must be locked when you use this method. Normally, you can call Access to lock the memory before starting an operation that uses this method, then call Release when the operation is finished.

Use the BytesPerLine property of the RasterImage object to determine the byte count of each line. Color order is determined by the Order property. This value can be RasterByteOrder.Rgb, RasterByteOrder.Bgr, RasterByteOrder.Gray or RasterByteOrder.RommRasterByteOrder.Gray is only valid for 12 and 16-bit grayscale images. Support for 12 and 16-bit grayscale images is only available in the Document/Medical Imaging editions.

Requirements

Target Platforms: Silverlight, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only), Windows Phone 7

See Also