CodecsTransformMarkerCallback Delegate

Summary

Handles the processing of every JPEG marker present in the file transformed by RasterCodecs.Transform.

Syntax

Objective-C

C++/CLI

Java

Python

public delegate CodecsTransformMarkerAction CodecsTransformMarkerCallback( 
   int id, 
   RasterNativeBuffer buffer, 
   CodecsTransformFlags transform 
)

typedef LTCodecsTransformMarkerAction (^LTCodecsTransformMarkerCallback)(NSInteger markerId, unsigned char *buffer, NSUInteger length, LTCodecsTransformFlags transform)

public CodecsTransformMarkerAction OnCodecsTransformMarkerCallback(int id, RasterNativeBuffer buffer, CodecsTransformFlags transform)

public delegate CodecsTransformMarkerAction CodecsTransformMarkerCallback(  
   int id, 
   RasterNativeBuffer buffer, 
   CodecsTransformFlags transform 
)

def CodecsTransformMarkerCallback(self,id,buffer,transform): 
# id : Int32, buffer : RasterNativeBuffer, transform : CodecsTransformFlags

Parameters

id
ID of the JPEG marker. The JPEG markers are uniquely identified by a byte value. Possible values are 1 to 254. (0 and 255 are not allowed.)

buffer
A pointer to the memory buffer containing the marker data. RasterNativeBuffer.Length contains the size in bytes of the JPEG marker. The size will be less than 65535. If this value is 0, then the marker does not have any extra data and buffer should be ignored.

transform
Flags that indicate the transform to be performed. These are the same flags passed to the RasterCodecs.Transform method.

Return Value

A CodecsTransformMarkerAction enumeration member that determines the action taken by the RasterCodecs after the callback is called. Possible values are:

Value	Description
CodecsTransformMarkerAction.Default	Successful. The default processing for this marker can be performed
CodecsTransformMarkerAction.Ignore	Successful. Do not process this marker and do not write it to the file
CodecsTransformMarkerAction.Abort	Abort the process and do not transform anymore markers

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
public void TransformExample() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
 
   string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_Transform.cmp"); 
 
 
   // Load the source image with markers 
   Debug.WriteLine("Loading the source image with all markers"); 
   codecs.Options.Load.Markers = true; 
   RasterImage srcImage = codecs.Load(srcFileName); 
 
   // Show the markers loaded, if any 
   Debug.WriteLine("These markers were loaded:"); 
   foreach (RasterMarkerMetadata marker in srcImage.Markers) 
   { 
      byte[] data = marker.GetData(); 
      codecs.WriteMarker(srcFileName, 1, marker); 
      // codecs.WriteMarker(stream, 1, marker); 
      codecs.WriteTransformMarker(marker.Id, data, 0, 1); 
      Debug.WriteLine(" {0}, DataSize:{1}", marker.Id, data.Length); 
   } 
 
   codecs.Transform( 
      srcFileName, 
      destFileName, 
      CodecsTransformFlags.Rotate90, 
      1, 
      CodecsTransformMarkerCallback); 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
CodecsTransformMarkerAction CodecsTransformMarkerCallback(int id, RasterNativeBuffer buffer, CodecsTransformFlags transform) 
{ 
   Debug.WriteLine("Transforming: id: {0}, Data Length: {1}, transform: {2}", id, buffer.Length, transform); 
   return CodecsTransformMarkerAction.Default; 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 
}

Requirements

Target Platforms

Reference

Leadtools.Codecs Namespace

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Help Version 22.0.2023.5.5

Leadtools.Codecs Assembly

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