GetRowCompressed(IntPtr,IntPtr,Int32,Int32) Method

C#
Visual Basic
WinRT C#
Objective-C
Java
WinRT JavaScript
C++

public void GetRowCompressed( 
   IntPtr workBuffer,
   IntPtr runBuffer,
   int row,
   int lines
)

'Declaration
 
Public Overloads Sub GetRowCompressed( _
   ByVal workBuffer As IntPtr, _
   ByVal runBuffer As IntPtr, _
   ByVal row As Integer, _
   ByVal lines As Integer _
)

'Usage
 
Dim instance As RasterImage
Dim workBuffer As IntPtr
Dim runBuffer As IntPtr
Dim row As Integer
Dim lines As Integer
 
instance.GetRowCompressed(workBuffer, runBuffer, row, lines)

public void GetRowCompressed( 
   IntPtr workBuffer,
   IntPtr runBuffer,
   int row,
   int lines
)

public void getRowCompressed(
  byte[] workBuffer, 
  short[] runBuffer, 
  int row, 
  int lines
)

 function Leadtools.RasterImage.GetRowCompressed(IntPtr,IntPtr,Int32,Int32)( 
   workBuffer ,
   runBuffer ,
   row ,
   lines 
)

public:
void GetRowCompressed( 
   IntPtr workBuffer,
   IntPtr runBuffer,
   int row,
   int lines
)

Parameters

workBuffer: Pointer to optional work unmanaged memory buffer. Allocating the work buffer speeds processing if you call this method more than once, because if you do not allocate a work buffer, the method allocates and frees a temporary buffer each time it is called. bytes required = lines * ((Width + 3) * 2). Pass IntPtr.Zero for workBuffer if you do not want to use the work buffer
runBuffer: Pointer to the output unmanaged memory buffer, which will be filled with 1-bit compressed image data.
row: The number of the row to retrieve. The first row is 0, and the last row is 1 less than the image height.
lines: Number of rows to retrieve.

This method is available in the (Document/Medical only) Toolkits.

This method is useful for working with 1-bit images that are loaded in their compressed formats for faster loading and display.

For more information, refer to Speeding Up 1-Bit Documents.

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

Copy Code

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.WinForms
Imports Leadtools.Dicom
Imports Leadtools.Drawing

Public Sub GetRowCompressedExample()
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Load the bitmap, at 1 bit per pixel, compressed
   codecs.Options.Load.Compressed = True
   Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "OCR1.TIF"), 1, CodecsLoadByteOrder.Bgr, 1, 1)

   ' This example does not work with rotated view perspectives.
   If (image.ViewPerspective <> RasterViewPerspective.TopLeft) OrElse (image.ViewPerspective <> RasterViewPerspective.BottomLeft) Then
      image.ChangeViewPerspective(RasterViewPerspective.TopLeft)
   End If

   ' Adjust the YOffset if the view perspective is bottom left.
   Dim nRow As Integer = 500 ' first row to get.
   Dim nYSize As Integer = 500 ' number of rows to get.

   If image.ViewPerspective = RasterViewPerspective.BottomLeft Then
      nRow = image.Height - nRow - nYSize
   End If

   ' Allocate the buffers.
   Dim pBuffer As Byte() = New Byte(Convert.ToInt32((((image.Width + 31) And Not (31)) / 8)) * nYSize - 1) {} ' Buffer to hold the expanded row.
   Dim pRunBuffer As System.UInt16() = New System.UInt16(((image.Width + 3) * 2) * nYSize - 1) {} ' Buffer to hold the compressed row.

   If image.IsGlobalMemory Then
      image.Access()
   End If
   ' Get the top nRow lines.
   image.GetRowCompressed(Nothing, pRunBuffer, 0, nRow, nYSize)
   ' Expand the compressed data.
   RasterRleCompressor.ExpandRows(pRunBuffer, pBuffer, 0, image.Width, nYSize)
   ' Invert the data.

   Dim n As Integer = 0
   Do While n < (image.BytesPerLine * nYSize)
      pBuffer(n) = pBuffer(n) Xor Convert.ToByte(&HFF)
      n += 1
   Loop


   ' Compress the inverted data.
   RasterRleCompressor.CompressRows(pRunBuffer, pBuffer, 0, image.Width, nYSize)

   ' Put the inverted, compressed data back into the image.
   image.SetRowCompressed(Nothing, pRunBuffer, 0, nRow, nYSize)

   If image.IsGlobalMemory Then
      image.Release()
   End If

   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_getrowcompresed.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

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.WinForms;
using Leadtools.Dicom;
using Leadtools.Drawing;

      
public void GetRowCompressedExample()
{
   RasterCodecs codecs = new RasterCodecs();
   // Load the bitmap, at 1 bit per pixel, compressed
   codecs.Options.Load.Compressed = true;
   RasterImage image = codecs.Load(Path.Combine(ImagesPath.Path, "OCR1.TIF"), 1, Leadtools.Codecs.CodecsLoadByteOrder.Bgr, 1, 1);
   // This example does not work with rotated view perspectives.
   if((image.ViewPerspective != RasterViewPerspective.TopLeft) || (image.ViewPerspective != RasterViewPerspective.BottomLeft))
      image.ChangeViewPerspective(RasterViewPerspective.TopLeft);

   // Adjust the YOffset if the view perspective is bottom left.
   int nRow = 500; // first row to get.
   int nYSize = 500; // number of rows to get.

   if(image.ViewPerspective == RasterViewPerspective.BottomLeft)
      nRow = image.Height - nRow - nYSize;

   // Allocate the buffers.
   byte[] pBuffer = new byte[Convert.ToInt32((((image.Width + 31) & ~(31)) / 8)) * nYSize]; // Buffer to hold the expanded row.
   ushort[] pRunBuffer = new ushort[((image.Width + 3) * 2) * nYSize]; // Buffer to hold the compressed row.

   if(image.IsGlobalMemory)
      image.Access();
   // Get the top nRow lines.
   image.GetRowCompressed(null, pRunBuffer, 0, nRow, nYSize);
   // Expand the compressed data.
   RasterRleCompressor.ExpandRows(pRunBuffer, pBuffer, 0, image.Width, nYSize);
   // Invert the data.

   for(int n = 0; n < (image.BytesPerLine * nYSize); n++)
      pBuffer[n] ^= 0xff;


   // Compress the inverted data.
   RasterRleCompressor.CompressRows(pRunBuffer, pBuffer, 0, image.Width, nYSize);

   // Put the inverted, compressed data back into the image.
   image.SetRowCompressed(null, pRunBuffer, 0, nRow, nYSize);

   if(image.IsGlobalMemory)
      image.Release();

   codecs.Save(image,Path.Combine(ImagesPath.Path,"IMAGE1_getrowcompresed.BMP"), RasterImageFormat.Bmp, 0);

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

Target Platforms

Reference

RasterImage Class
RasterImage Members
Overload List