Types of File Comments

LEAD supports reading and writing of image file comments.

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

Image Metadata, Comments, and Tags

Some file formats can contain comments, and some cannot, and each file format has its own set of comment types.

Exif files contain either uncompressed TIFF images or compressed JPEG images. These files can contain many comment fields of various types called metadata.

Metadata

Metadata refers to extra information stored with the image file that is not necessary for decoding the image. Metadata can contain comments describing the contents in the file format.

Comments

A comment in the context of TIFF file formats, refer to metadata that can be read from the file or saved to it. For example, a TIFF comment to describe the file is saved using the RasterCommentMetadataType.Description tag.

Tags

A tag identifies data that describes content in a file format, such as TIFF. Tags is a collection contained in the file format (e.g., tags to read\write TIFF metadata ).

Resources

Below is a table providing reference material related to Exif (TIFF and JPEG) metadata:

Resource Description
File Formats: Exif Formats (TIFF and JPG) LEADTOOLS reads and writes Exif formats: TIFF and JPG.
Implementing TIFF Comments and Tags TIFF file formats support a number of comments that are saved and loaded using predefined tags . To specify the comments or tags set them directly in the image. Define a custom tag for saving additional non-raster data in a TIFF file (e.g., define a tag to save annotations).
TIFF File Comments TIFF file formats comment type have predefined fields in LEADTOOLS and available to read and save them. Size restrictions apply, refer to this topic for further details.
RasterMetadata Leadtools assembly class to support read/write metadata stored in various image file formats. Code example is provided.
RasterCommentMetadata Leadtools assembly class that extends RasterMetadata to support read/write metadata stored in various image file formats. Code example is provided.
RasterTagMetadata Leadtools aseembly class that extends RasterMetadata to support tag metadata stored within various image file formats. Code example is provided.
Working With Private TIFF Tags LEADTOOLS allows private tags when creating them inside an IFD (Image File Directory). Code example is provided.
RasterCodecs.WriteTag Leadtools.Codecs assembly class to support read/write TIFF tags to a file or stream.
Loading and Saving Large TIFF/BigTIFF Files TIFF and BigTIFF file formats comparison and LEADTOOLS support. TIFF files are limited to 4GB, BigTIFF, however, can create larger files.
CodecsTiffOptions Leadtools.Codecs assembly class that provides extra options for loading and saving TIFF images (e.g., defining Tile height and width). Code example is provided.

Related Topics

DICOM File Comments
Exif File Comments
Exif File Extensions
GIF File Comments
Heif/Heic File Comments
IPTC Comments
JPEG 2000 File Comments
JPEG and LEAD File Comments
PNG File Comments
TIFF File Comments
WebP File Comments
Notes on Exif Data
Non-Image Data
Working with Markers
Help Version 22.0.2023.7.17
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LEADTOOLS Imaging, Medical, and Document
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.