←Select platform

RasterCommentMetadata Class

Extends the RasterMetadata class to provide functionality for dealing with comment metadata stored within various image file formats.
public class RasterCommentMetadata : RasterMetadata 
@interface LTRasterCommentMetadata : LTRasterMetadata 
public class RasterCommentMetadata 
    extends RasterMetadata 
    implements java.io.Serializable 
public ref class RasterCommentMetadata : public RasterMetadata  
class RasterCommentMetadata(RasterMetadata): 

The TIFF file formats support a number of comments that are saved and loaded using predefined tags.

If the comments do not meet your needs, you can define your own tag for saving additional non-raster data in a TIFF file. For example, you may want to define a tag to save annotations.

The TIFF 6.0 Specification sets aside a range of private tags that developers can define. To avoid conflicts with files created by other developers, you can register your tag by contacting Adobe Developer Relations. The E-Mail address posted on The Unofficial TIFF Home Page is gapdevsup@adobe.com.

Some restrictions apply to this function if you use an IFD to indicate to which page to write the metadata. See the Loading And Saving Large TIFF Files topic for more information.


This example will write comments of different data types to an existing tif file then read them as a test.

using Leadtools; 
using Leadtools.Codecs; 
public void RasterCommentMetadataExample() 
	RasterCodecs codecs = new RasterCodecs(); 
	codecs.ThrowExceptionsOnInvalidImages = true; 
	string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_comments.tif"); 
	// Load the image 
	RasterImage image = codecs.Load(srcFileName); 
	codecs.Save(image, destFileName, RasterImageFormat.Tif, 24); 
	// Write some comments to the existing tif file 
	RasterCommentMetadata comment = new RasterCommentMetadata(); 
	comment.Type = RasterCommentMetadataType.Artist; 
	string artistNameWrite = "Artist name"; 
	Console.WriteLine("Writing Artist"); 
	codecs.WriteComment(destFileName, 1, comment); 
	comment.Type = RasterCommentMetadataType.GpsLatitude; 
	RasterMetadataRational[] rationalsWrite = new RasterMetadataRational[3]; 
	for (int i = 0; i < rationalsWrite.Length; i++) 
		rationalsWrite[i] = new RasterMetadataRational(i + 3, i + 2); 
	Console.WriteLine("Writing GpsLatitude"); 
	codecs.WriteComment(destFileName, 1, comment); 
	// Now read the comments from the tif file 
	// read ASCII 
	comment = codecs.ReadComment(destFileName, 1, RasterCommentMetadataType.Artist); 
	string artistNameRead = comment.ToAscii(); 
	Console.WriteLine("Artist: {0}", artistNameRead); 
	Assert.IsTrue(artistNameRead == artistNameWrite); 
	// read rationals 
	comment = codecs.ReadComment(destFileName, 1, RasterCommentMetadataType.GpsLatitude); 
	RasterMetadataRational[] rationalsRead = comment.ToRational(); 
	int size = rationalsRead.Length; 
	Console.WriteLine("GpsLatitude: size = {0} ", size); 
	for (int i = 0; i < size; i++) 
		Console.WriteLine("{0}/{1}", rationalsRead[i].Numerator, rationalsRead[i].Denominator); 
	Assert.IsTrue(rationalsRead.Length == rationalsWrite.Length); 
	for (int i = 0; i < rationalsRead.Length; i++) 
		Assert.IsTrue(rationalsRead[i].Numerator == rationalsWrite[i].Numerator); 
		Assert.IsTrue(rationalsRead[i].Denominator == rationalsWrite[i].Denominator); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 

Target Platforms

Help Version 22.0.2023.5.16
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

Leadtools Assembly

Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.