CodecsOverlayCallback Delegate

Summary

Provides a callback method that gets called when loading a file containing an overlay.

Syntax

Objective-C

C++/CLI

Java

Python

public delegate void CodecsOverlayCallback( 
   CodecsOverlayData data 
)

typedef void (^LTCodecsOverlayCallback)(LTCodecsOverlayData *data)

public void onOverlay(CodecsOverlayData data)

public delegate void CodecsOverlayCallback(  
   CodecsOverlayData^ data 
)

def CodecsOverlayCallback(self,data): 
# data : CodecsOverlayData

Parameters

data
A CodecsOverlayData object that contains information about the callback. Some members of this object are for input, some are for output. For more information, refer to CodecsOverlayData.

Remarks

The CodecsOverlayCallback delegate is passed to RasterCodecs.StartOverlay to get the overlay image and other information from the user when loading a file containing an overlay.

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
void PtokaOverlayExample(string ptokaFileName, string ptokaFilesPath) 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Set up the private variables used in the callback 
   myCodecs = codecs; 
   myPtokaFilesPath = ptokaFilesPath; 
 
   // Set the overlay callback 
   codecs.StartOverlay(CodecsOverlayCallback, CodecsOverlayCallbackMode.CallLoad); 
 
   // Load the PTOKA file 
   RasterImage image = codecs.Load(ptokaFileName); 
 
   // Stop the overlay by resetting the old callback. 
   codecs.StopOverlay(); 
 
   // Save the image as TIFF 
   string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "PtokaOverlay.tif"); 
   codecs.Save(image, destFileName, RasterImageFormat.Tif, 1); 
   image.Dispose(); 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
RasterCodecs myCodecs; 
string myPtokaFilesPath; 
 
void CodecsOverlayCallback(CodecsOverlayData data) 
{ 
   // Show overlay information 
   Debug.WriteLine("File: {0}", data.FileName); 
   Debug.WriteLine("Page Number: {0}", data.PageNumber); 
   Debug.WriteLine("Info: {0}", data.Info); 
 
   // Construct the overlay file name 
   string overlayFileName = Path.Combine(myPtokaFilesPath, data.FileName); 
 
   if (data.Info) 
   { 
      // Info, we only need to fill in the .InfoXXX members of the data 
      CodecsImageInfo imageInfo = myCodecs.GetInformation(overlayFileName, false); 
      data.InfoWidth = imageInfo.Width; 
      data.InfoHeight = imageInfo.Height; 
      data.InfoXResolution = imageInfo.XResolution; 
      data.InfoYResolution = imageInfo.YResolution; 
   } 
   else 
   { 
      // We need to load the overlay image into the .Image member 
      data.Image = myCodecs.Load(overlayFileName); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.*; 
import java.net.*; 
import java.nio.file.Paths; 
import java.util.*; 
import java.time.Instant; 
import java.time.Duration; 
 
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.codecs.RasterCodecs.FeedCallbackThunk; 
import leadtools.drawing.internal.*; 
import leadtools.imageprocessing.*; 
import leadtools.imageprocessing.color.ChangeIntensityCommand; 
import leadtools.svg.*; 
 
 
public void ptokaOverlayExample() { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String ptokaFileName = combine(LEAD_VARS_IMAGES_DIR, "jbig.jbg"); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Set up the private variables used in the callback 
   myCodecs = codecs; 
   myPtokaFilesPath = LEAD_VARS_IMAGES_DIR; 
 
   // Set the overlay callback 
   codecs.startOverlay(codecsOverlayCallback, CodecsOverlayCallbackMode.CALL_LOAD); 
 
   // Load the PTOKA file 
   RasterImage image = codecs.load(ptokaFileName); 
 
   // Stop the overlay by resetting the old callback. 
   codecs.stopOverlay(); 
 
   // Save the image as TIFF 
   String destFileName = combine(LEAD_VARS_IMAGES_DIR, "PtokaOverlay.tif"); 
   codecs.save(image, destFileName, RasterImageFormat.TIF, 1); 
   image.dispose(); 
 
   // Clean up 
   codecs.dispose(); 
} 
 
RasterCodecs myCodecs; 
String myPtokaFilesPath; 
CodecsOverlayListener codecsOverlayCallback = new CodecsOverlayListener() { 
 
   @Override 
   public void onOverlay(CodecsOverlayData data) { 
      // Show overlay information 
      System.out.println("File: " + data.getFileName()); 
      System.out.println("Page Number: " + data.getPageNumber()); 
      System.out.println("Info: " + data.getInfo()); 
 
      // Construct the overlay file name 
      String overlayFileName = combine(myPtokaFilesPath, data.getFileName()); 
 
      if (data.getInfo()) { 
         // Info, we only need to fill in the .InfoXXX members of the data 
         CodecsImageInfo imageInfo = myCodecs.getInformation(overlayFileName, false); 
         data.setInfoWidth(imageInfo.getWidth()); 
         data.setInfoHeight(imageInfo.getHeight()); 
         data.setInfoXResolution(imageInfo.getXResolution()); 
         data.setInfoYResolution(imageInfo.getYResolution()); 
      } else { 
         // We need to load the overlay image into the .Image member 
         data.setImage(myCodecs.load(overlayFileName)); 
      } 
   } 
 
};

Requirements

Target Platforms

Reference

Leadtools.Codecs Namespace

Download our FREE evaluation

Help Version 23.0.2024.2.29