TIFF File Comments

When reading or updating TIFF comments, you must specify the comment type using the following constants.

For TIFF files: Each comment field can contain a character string. The maximum field size is 32K, except for the date-time field, which are always 20.

Note that LEADTOOLS also supports IPTC Comments, which can be saved inside TIFF files. For more information, refer to IPTC Comments.

Initially, only TIFF files supported TIFF tags. But the TIFF tags are so flexible and well documented that other formats added mechanisms for including TIFF tags:

As a result, the file formats listed above also support TIFF and Exif comments.

Value Meaning
RasterCommentMetadataType.Artist Person who created the image.
RasterCommentMetadataType.Copyright Copyright notice.
RasterCommentMetadataType.DateTime Date and time (YYYY:MM:DD HH:MM:SS). The field length is 20, counting the NULL terminator.
RasterCommentMetadataType.Description Description of the image.
RasterCommentMetadataType.HostComputer Computer and operating system in use.
RasterCommentMetadataType.Make Manufacturer of the equipment used to create the image.
RasterCommentMetadataType.Model Model name and number of the equipment.
RasterCommentMetadataType.NameOfDocument Name of the document from which the image was scanned.
RasterCommentMetadataType.NameOfPage Page name from which the image was scanned.
RasterCommentMetadataType.Software Name and version of the software package used to create the image.

Note

If you are using the Nag version of Leadtools.dll, this comment is fixed and cannot be changed. | |

To obtain specified tagged data from a TIFF file or stream, use one of the RasterCodecs.ReadTag methods. To write or change a tag to an existing file, use one of the RasterCodecs.WriteTag or RasterCodecs.WriteTags methods.

For more information about file comments, refer to RasterCodecs.ReadComment and RasterCodecs.WriteComment.

For technical reasons, the following restrictions apply when you pass an IFD offset by setting the RasterCodecs.Options.Tiff.Load.ImageFileDirectoryOffset property if you set PageNumber to 1:

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LEADTOOLS Imaging, Medical, and Document
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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.