GetRow(int,byte[],int,int) Method

Summary

Retrieves one or more rows of image data from this RasterImage into a managed memory buffer.

Syntax

Objective-C

C++

Java

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

Public Overloads Function GetRow( _ 
   ByVal row As Integer, _ 
   ByVal buffer() As Byte, _ 
   ByVal bufferIndex As Integer, _ 
   ByVal bufferCount As Integer _ 
) As Integer

- (NSInteger)getRow:(NSInteger)row  
             buffer:(unsigned char *)buffer  
        bufferCount:(unsigned long)count  
              error:(NSError **)error

public long getRow( 
  int row,  
  byte[] buffer,  
  int bufferIndex,  
  long 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 * (Image.Width * Image.Height + 7) / 8;

Return Value

The number of bytes copied.

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.

Note: The data in the buffer will be padded to BytesPerLine.

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.Romm. RasterByteOrder.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.

Example

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

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Core; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Dicom; 
using Leadtools.Drawing; 
using Leadtools.Controls; 
using Leadtools.Svg; 
 
 
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]; 
 
	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); 
	} 
	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:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Core 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Controls 
Imports Leadtools.Dicom 
Imports Leadtools.Drawing 
Imports Leadtools.Svg 
 
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) {} 
 
   image.Access() 
   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 
   image.Release() 
 
   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:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

RasterImage Class

RasterImage Members

Overload List

Download our FREE evaluation

Help Version 21.0.2021.7.2