RasterImageResize Class

Summary

Provides support for resizing images.

Syntax

C++

public class RasterImageResize

Public Class RasterImageResize

public ref class RasterImageResize

Remarks

This class supports changing the color order, bits per pixel and/or palette, during the resize operation.

Example

This sample loads an image and uses the RasterImageResize class to resize it to half its size.

using Leadtools; 
using Leadtools.Codecs; 
 
 
public void RasterImageResizeExample() 
{ 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_RasterImageResize.bmp"); 
 
	using (RasterCodecs codecs = new RasterCodecs()) 
	{ 
		// Load the source image 
		using (RasterImage srcImage = codecs.Load(srcFileName)) 
		{ 
			// We will resize to half the original size 
			int destWidth = srcImage.Width / 2; 
			int destHeight = srcImage.Height / 2; 
 
			// Create the destination image 
			using (RasterImage destImage = new RasterImage( 
			   RasterMemoryFlags.Conventional, 
			   destWidth, 
			   destHeight, 
			   srcImage.BitsPerPixel, 
			   srcImage.Order, 
			   srcImage.ViewPerspective, 
			   srcImage.GetPalette(), 
			   IntPtr.Zero, 
			   0)) 
			{ 
				RasterImageResize resize = new RasterImageResize(); 
 
				// Add Event Handler 
				resize.Resize += new EventHandler<RasterImageResizeEventArgs>(resize_Resize); 
 
				byte[] buffer = new byte[destImage.BytesPerLine]; 
 
				// Start the resize process 
				resize.Start( 
				   srcImage, 
				   destWidth, 
				   destHeight, 
				   srcImage.BitsPerPixel, 
				   srcImage.Order, 
				   srcImage.DitheringMethod, 
				   RasterSizeFlags.None, 
				   srcImage.GetPalette()); 
 
				destImage.Access(); 
				// get the rows for the resized image, one by one 
				for (int row = 0; row < destImage.Height; row++) 
				{ 
					resize.ResizeBuffer(row, 0, buffer, 0, destImage.BytesPerLine); 
					destImage.SetRow(row, buffer, 0, destImage.BytesPerLine); 
				} 
				destImage.Release(); 
				resize.Stop(); 
 
				// Save the destination image 
				codecs.Save(destImage, destFileName, RasterImageFormat.Bmp, 24); 
			} 
		} 
	} 
} 
 
private void resize_Resize(object sender, RasterImageResizeEventArgs e) 
{ 
	// e.Row should ALWAYS be less than e.Image.Height 
	if (e.Row >= e.Image.Height) 
	{ 
		e.Cancel = true; // abort the resize 
		return; 
	} 
 
	byte[] buffer = new byte[e.Bytes]; 
	e.Image.Access(); 
	e.Image.GetRowColumn(e.Row, e.Column, buffer, 0, e.Bytes); 
	e.Image.Release(); 
	Marshal.Copy(buffer, 0, e.Buffer, e.Bytes); 
	Console.WriteLine("{0}, {1}", e.Row, e.Column); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
 
Public Sub RasterImageResizeExample() 
   Dim codecs As RasterCodecs = New RasterCodecs() 
   codecs.ThrowExceptionsOnInvalidImages = True 
 
   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_RasterImageResize.bmp") 
 
   ' Load the source image 
   Dim srcImage As RasterImage = codecs.Load(srcFileName) 
 
   Dim resize As RasterImageResize = New RasterImageResize() 
 
   ' Add Handler 
   AddHandler resize.Resize, AddressOf resize_Resize 
 
   ' We will resize to half the original size 
   Dim destWidth As Integer = srcImage.Width \ 2 
   Dim destHeight As Integer = srcImage.Height \ 2 
 
   ' Start the resize process 
   resize.Start(srcImage, destWidth, destHeight, srcImage.BitsPerPixel, srcImage.Order, 
                srcImage.DitheringMethod, RasterSizeFlags.None, srcImage.GetPalette()) 
 
   ' Create the destination image 
 
   Dim destImage As RasterImage = New RasterImage( 
                                  RasterMemoryFlags.Conventional, destWidth, destHeight, 
                                  srcImage.BitsPerPixel, srcImage.Order, srcImage.ViewPerspective, srcImage.GetPalette(), IntPtr.Zero, 0) 
 
   Dim buffer As Byte() = New Byte(destImage.BytesPerLine - 1) {} 
 
   ' get the rows for the resized image, one by one 
   Dim row As Integer = 0 
   srcImage.Access() 
   destImage.Access() 
   Do While row < destImage.Height 
      resize.ResizeBuffer(row, 0, buffer, 0, destImage.BytesPerLine) 
      destImage.SetRow(row, buffer, 0, destImage.BytesPerLine) 
      row += 1 
   Loop 
   srcImage.Release() 
   destImage.Release() 
 
   resize.Stop() 
 
   ' save the destination image 
   codecs.Save(destImage, destFileName, RasterImageFormat.Bmp, 24) 
 
   ' clean up 
   srcImage.Dispose() 
   destImage.Dispose() 
End Sub 
 
Private Sub resize_Resize(ByVal sender As Object, ByVal e As RasterImageResizeEventArgs) 
   ' e.Row should ALWAYS be less than e.Image.Height 
   If e.Row >= e.Image.Height Then 
      e.Cancel = True ' abort the resize 
      Return 
   End If 
 
   Dim buffer As Byte() = New Byte(e.Bytes - 1) {} 
   e.Image.Access() 
   e.Image.GetRowColumn(e.Row, e.Column, buffer, 0, e.Bytes) 
   e.Image.Release() 
   Marshal.Copy(buffer, 0, e.Buffer, e.Bytes) 
   Console.WriteLine("{0}, {1}", e.Row, e.Column) 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class

Requirements

Target Platforms

Reference

RasterImageResize Members

Leadtools Namespace

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Help Version 21.0.2021.7.2

Leadtools Assembly

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Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies