RasterDefaults Class

Summary

Specifies the default extra values used when creating RasterImage objects.

Syntax

Objective-C

C++/CLI

Java

Python

public static class RasterDefaults

@interface LTRasterDefaults : NSObject

public class RasterDefaults

public ref class RasterDefaults abstract sealed

class RasterDefaults:

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); 
}

Requirements

Target Platforms

Reference

RasterDefaults Members

Leadtools Namespace

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Help Version 22.0.2023.5.16

Leadtools Assembly

Introduction

Getting Started

Namespaces

Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies