Exif Formats (TIFF and JPG)

Exif is a standard for image files created with digital cameras and other input devices. The standard is set by the Japan Electronic Industry Development Association, and formally it is called the Digital Still Camera Image File Format Standard.

Exif files contain either uncompressed TIFF images or compressed JPEG images. In addition, these files can contain many comment fields of various types. You can use the ReadComment method to read comments in an existing file. Before writing a file, you can use the Comment property to create an array of comments to be saved in the file.

LEADTOOLS reads and writes the following Exif formats:

TIFF. This is a tag-based file format designed to promote universal interchanges of digital image data. You can save any image size.

JPG. This is the JPEG format with YUV 4:2:2 sampling. You can save any image size.

For more information, refer to Compression Using LEAD and JPEG Formats.

If you are working with compressed (JPEG) Exif  files, the stamp size has been restricted to 160x120x24. When you call the  SaveWithStamp method and specify that you want to save a compressed Exif file, the StampWidth, StampHeight and StampBits parameters are ignored. They are assumed to be 160 (StampWidth), 120 (StampHeight) and 24 (StampBits). That limitation has been imposed in order to conform with the ExifR98 interoperability rules imposed by Japanese digital camera manufacturers.

If you are working with uncompressed (TIFF) Exif files, the stamp size is (width x height x 24 bpp), with no limitations on width and height.

The stamp image can be retrieved by calling the LoadStamp method.

File constants associated with these file formats are:

Required DLL: LFTIF, LFCMP. For a listing of the exact DLLs needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Related Formats: JPG - JPEG Compressed, TIFF - Tagged Image File Format.