RasterDefaults Class

Summary

Specifies the default extra values used when creating RasterImage objects.

Syntax

Objective-C

C++

Java

public static class RasterDefaults

Public MustInherit NotInheritable Class RasterDefaults

@interface LTRasterDefaults : NSObject

public class RasterDefaults

public ref class RasterDefaults abstract sealed

Remarks

You can use the RasterDefaults class to specify extra attributes used when creating a RasterImage object.

For example, you can use XResolution and YResolution to set the physical resolution (DPI) of all the RasterImage objects created afterwards.

You can use DitheringMethod to specify the default dithering method to use when converting an image from 64, 48, 32, 24, or 16 bits per pixel to 8 bits per pixel or fewer.

MemoryFlags and MemoryThreshold controls how newly created images use the system memory. The TemporaryDirectory controls where disk-based images are stored.

Use GetGlobalMemoryThresholds and SetGlobalMemoryThresholds to modify the conventional memory restrictions used when allocating new RasterImage objects.

Example

using Leadtools; 
using Leadtools.Codecs; 
 
 
public void RasterDefaultsExample() 
{ 
	// Set the limit for RasterImage object allocations 
	RasterMemoryThreshold threshold = RasterDefaults.MemoryThreshold; 
	threshold.MaximumGlobalRasterImageMemory = 20 * 1000 * 1024; 
	RasterDefaults.MemoryThreshold = threshold; 
 
	ShowValues(); 
 
	// Create a raster image with current DPI 
	RasterImage image1 = new RasterImage( 
	   RasterMemoryFlags.Conventional, 
	   100, 
	   100, 
	   24, 
	   RasterByteOrder.Bgr, 
	   RasterViewPerspective.TopLeft, 
	   null, 
	   IntPtr.Zero, 
	   0); 
	Console.WriteLine("Resolution of created image is {0} by {1} DPI", image1.XResolution, image1.YResolution); 
 
	// Change the resolution 
	int xOldResolution = RasterDefaults.XResolution; 
	int yOldResolution = RasterDefaults.YResolution; 
	int xNewResolution = 196; 
	int yNewResolution = 196; 
	RasterDefaults.XResolution = xNewResolution; 
	RasterDefaults.YResolution = yNewResolution; 
	ShowValues(); 
 
	// Create another raster image 
	// Create a raster image with current DPI 
	RasterImage image2 = new RasterImage( 
	   RasterMemoryFlags.Conventional, 
	   100, 
	   100, 
	   24, 
	   RasterByteOrder.Bgr, 
	   RasterViewPerspective.TopLeft, 
	   null, 
	   IntPtr.Zero, 
	   0); 
	Console.WriteLine("Resolution of created image is {0} by {1} DPI", image2.XResolution, image2.YResolution); 
	Debug.Assert(image2.XResolution == xNewResolution); 
	Debug.Assert(image2.YResolution == yNewResolution); 
 
	// Reset old values 
	RasterDefaults.XResolution = xOldResolution; 
	RasterDefaults.YResolution = yOldResolution; 
 
	image1.Dispose(); 
	image2.Dispose(); 
} 
 
void ShowValues() 
{ 
	Console.WriteLine("Current defaults:"); 
	Console.WriteLine("MaximumThreadCount: {0}", RasterDefaults.MaximumThreadCount); 
	Console.WriteLine("XResolution: {0}", RasterDefaults.XResolution); 
	Console.WriteLine("YResolution: {0}", RasterDefaults.YResolution); 
	Console.WriteLine("DitheringMethod: {0}", RasterDefaults.DitheringMethod); 
	Console.WriteLine("MemoryFlags: {0}", RasterDefaults.MemoryFlags); 
 
	RasterMemoryThreshold threshold = RasterDefaults.MemoryThreshold; 
	Console.WriteLine("MemoryThreshold.TiledThreshold: {0}", threshold.TiledThreshold); 
	Console.WriteLine("MemoryThreshold.MaximumConventionalSize: {0}", threshold.MaximumConventionalSize); 
	Console.WriteLine("MemoryThreshold.TileSize: {0}", threshold.TileSize); 
	Console.WriteLine("MemoryThreshold.ConventionalTiles: {0}", threshold.ConventionalTiles); 
	Console.WriteLine("MemoryThreshold.ConventionalBuffers: {0}", threshold.ConventionalBuffers); 
	Console.WriteLine("MemoryThreshold.MaximumGlobalRasterImageMemory: {0}", threshold.MaximumGlobalRasterImageMemory); 
 
	Console.WriteLine("TemporaryDirectory: {0}", RasterDefaults.TemporaryDirectory); 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
 
Public Sub RasterDefaultsExample() 
   ' Set the limit for RasterImage object allocations 
   Dim threshold As RasterMemoryThreshold = RasterDefaults.MemoryThreshold 
   threshold.MaximumGlobalRasterImageMemory = 20 * 1000 * 1024 
   RasterDefaults.MemoryThreshold = threshold 
 
   ShowValues() 
 
   ' Create a raster image with current DPI 
   Dim image1 As RasterImage = New RasterImage(RasterMemoryFlags.Conventional, 100, 100, 24, RasterByteOrder.Bgr, RasterViewPerspective.TopLeft, Nothing, IntPtr.Zero, 0) 
   Console.WriteLine("Resolution of created image is {0} by {1} DPI", image1.XResolution, image1.YResolution) 
 
   ' Change the resolution 
   Dim xOldResolution As Integer = RasterDefaults.XResolution 
   Dim yOldResolution As Integer = RasterDefaults.YResolution 
   Dim xNewResolution As Integer = 196 
   Dim yNewResolution As Integer = 196 
   RasterDefaults.XResolution = xNewResolution 
   RasterDefaults.YResolution = yNewResolution 
   ShowValues() 
 
   ' Create another raster image 
   ' Create a raster image with current DPI 
   Dim image2 As RasterImage = New RasterImage(RasterMemoryFlags.Conventional, 100, 100, 24, RasterByteOrder.Bgr, RasterViewPerspective.TopLeft, Nothing, IntPtr.Zero, 0) 
   Console.WriteLine("Resolution of created image is {0} by {1} DPI", image2.XResolution, image2.YResolution) 
   Debug.Assert(image2.XResolution = xNewResolution) 
   Debug.Assert(image2.YResolution = yNewResolution) 
 
   ' Reset old values 
   RasterDefaults.XResolution = xOldResolution 
   RasterDefaults.YResolution = yOldResolution 
 
   image1.Dispose() 
   image2.Dispose() 
End Sub 
 
Private Sub ShowValues() 
   Console.WriteLine("Current defaults:") 
   Console.WriteLine("MaximumThreadCount: {0}", RasterDefaults.MaximumThreadCount) 
   Console.WriteLine("XResolution: {0}", RasterDefaults.XResolution) 
   Console.WriteLine("YResolution: {0}", RasterDefaults.YResolution) 
   Console.WriteLine("DitheringMethod: {0}", RasterDefaults.DitheringMethod) 
   Console.WriteLine("MemoryFlags: {0}", RasterDefaults.MemoryFlags) 
 
   Dim threshold As RasterMemoryThreshold = RasterDefaults.MemoryThreshold 
   Console.WriteLine("MemoryThreshold.TiledThreshold: {0}", threshold.TiledThreshold) 
   Console.WriteLine("MemoryThreshold.MaximumConventionalSize: {0}", threshold.MaximumConventionalSize) 
   Console.WriteLine("MemoryThreshold.TileSize: {0}", threshold.TileSize) 
   Console.WriteLine("MemoryThreshold.ConventionalTiles: {0}", threshold.ConventionalTiles) 
   Console.WriteLine("MemoryThreshold.ConventionalBuffers: {0}", threshold.ConventionalBuffers) 
   Console.WriteLine("MemoryThreshold.MaximumGlobalRasterImageMemory: {0}", threshold.MaximumGlobalRasterImageMemory) 
 
   Console.WriteLine("TemporaryDirectory: {0}", RasterDefaults.TemporaryDirectory) 
End Sub

Requirements

Target Platforms

Reference

RasterDefaults Members

Leadtools Namespace

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Leadtools Assembly

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Leadtools Namespace

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