Public Overloads 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)

public int GetRow( 
   int row,
   byte[] buffer,
   int bufferIndex,
   int bufferCount
)

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

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

Visual Basic

Copy Code

Public Sub GetRowTest()    RasterCodecs.Startup()    Dim codecs As RasterCodecs = New RasterCodecs()    Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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, LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_getrow.BMP", RasterImageFormat.Bmp, 0)    image.Dispose()    codecs.Dispose()    RasterCodecs.Shutdown() End Sub

C#

Copy Code

public void GetRowTest()  {     RasterCodecs.Startup();     RasterCodecs codecs = new RasterCodecs();     RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "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, LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_getrow.BMP", RasterImageFormat.Bmp, 0);       image.Dispose();     codecs.Dispose();     RasterCodecs.Shutdown();  }

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.

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

Reference