AccessData Method

Summary

Provides exclusive access to the image data contained in this RasterImage.

Syntax

Objective-C

- (BOOL)accessData:(NSError **)error

Remarks

If the image data of this RasterImage object is stored in a global Windows handle, then use the AccessData method to lock the memory. If you do not call this method before accessing the data with a low-level method like GetRow or SetRow the application might fail.

To make the most of available system resources, you should only keep a RasterImage object locked when you need to access the image data. Call Release to unlock the image data for more efficient use of system memory resources.

If the image data of this RasterImage is not stored in a global Windows handle, then this method will do nothing and calling it will not have any effect on the RasterImage.

Use IsGlobalMemory to determine whether the image data of this RasterImage is stored in a global Windows handle.

Example

Java

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:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.util.ArrayList; 
import java.util.List; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.imageprocessing.core.*; 
import leadtools.svg.*; 
import leadtools.imageprocessing.CloneCommand; 
import leadtools.imageprocessing.FillCommand; 
import leadtools.imageprocessing.FlipCommand; 
import leadtools.imageprocessing.GrayscaleCommand; 
import leadtools.imageprocessing.color.InvertCommand; 
import leadtools.imageprocessing.color.PosterizeCommand; 
 
 
public void getRowExample() { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   RasterCodecs codecs = new RasterCodecs(); 
   String destFileName = combine(LEAD_VARS_IMAGES_DIR, "Image1_getrow.BMP"); 
   RasterImage image = codecs.load(combine(LEAD_VARS_IMAGES_DIR, "IMAGE1.CMP")); 
   byte[] row1 = new byte[image.getBytesPerLine()]; 
   byte[] row2 = new byte[image.getBytesPerLine()]; 
 
   image.access(); 
 
   for (int y = 0; y < image.getHeight() / 2; y++) { 
      image.getRow(y, row1, 0, row1.length); 
      image.getRow(image.getHeight() - y - 1, row2, 0, row2.length); 
 
      image.setRow(y, row2, 0, row2.length); 
      image.setRow(image.getHeight() - y - 1, row1, 0, row1.length); 
   } 
 
   image.release(); 
 
   // Save it 
   codecs.save(image, destFileName, RasterImageFormat.BMP, 0); 
 
   // Clean up 
   image.dispose(); 
   codecs.dispose(); 
 
   assertTrue("file unsuccessfully saved to " + destFileName, (new File(destFileName)).exists()); 
   System.out.printf("File saved successfully to %s%n", destFileName); 
}

Requirements

Target Platforms

Reference

RasterImage Class

RasterImage Members

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Help Version 23.0.2024.5.22

Leadtools Assembly

Introduction

Getting Started

Namespaces

Leadtools Namespace

Leadtools.ImageProcessing Namespace

Assemblies