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.

LEADTOOLS writes the following Exif formats:

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

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

For more information, refer to Compression Quality Factors.

An Exif JPG file can also contain a stamp (thumbnail) image, which is a small copy of the main image. The stamp size has been restricted to 160x120x24. When saving Exif files, the nStampWidth, nStampHeight, and nStampBits members of the EPNRASTEROPTIONS structure will be ignored and 160 (StampWidth), 120 (StampHeight) and 24 (StampBits) will be used instead. 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.

File constants associated with these file formats are:

Constant	Write Support	Description
FILE_EXIF	24 BPP	[96] Exif file containing a TIFF image, with no compression and with RGB color space.
FILE_EXIF_YCC	24 BPP	[97] Exif file containing a TIFF image, with no compression and with YCbCr color space.
FILE_EXIF_JPEG_422	24 BPP	[98] Exif file containing a JPEG compressed image and YUV 4:2:2 color space.
FILE_EXIF_JPEG_411	24 BPP	[101] Exif file containing a JPEG compressed image and YUV 4:1:1 color space.

Required DLL: LFTIF, LFCMP. For a listing of the exact DLLs needed, refer to ePrint Files.