Difference between revisions of "EXIF"

From PanoTools.org Wiki
Jump to: navigation, search
m (categorised)
Line 1: Line 1:
EXIF stands for Exchangeable Image File Format.  It allows camera, lens, exposure information, image description, copyright, etc. to be embedded in an image file (typically a [[JPEG]] image).
+
EXIF stands for Exchangeable Image File Format.  It allows camera, lens, exposure information, image description, copyright, etc. to be embedded in standardized fields within JFIF ([[JPEG]]) or TIFF image files. EXIF is a de facto standard promoted by the camera industry as a means to store metadata recorded by a digital camera, and is not intended as a general-purpose metadata storage mechanism. [[XMP]] is a more generalized format for storing arbitrary metadata in a variety of media file formats.
  
 
For more detailed information, see the home page for [http://www.sno.phy.queensu.ca/~phil/exiftool/ ExifTool], especially the tables of [http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/index.html ExifTool Tag Names] and [http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html EXIF Tags].
 
For more detailed information, see the home page for [http://www.sno.phy.queensu.ca/~phil/exiftool/ ExifTool], especially the tables of [http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/index.html ExifTool Tag Names] and [http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/EXIF.html EXIF Tags].
  
[http://www.sno.phy.queensu.ca/~phil/exiftool/ ExifTool] is free software that allows manipulation of EXIF and related data in many different kinds of files.
+
As you'll note from the ExifTool pages above, there are many redundant fields due to different manufacturers defining unique fields for semantically identical information, as well as fields which are intended to store manufacturer-specific metadata. Many of these fields are undocumented, at least as far as the public is concerned, and so there is much energy in the industry devoted to decoding these unique fields, their semantics and their constraints.
  
A caution: at [http://groups.yahoo.com/group/PanoTools/message/16780], it is written that
+
While EXIF is not generally intended to be user editable, there are a large number of tools that are capable of editing EXIF metadata with varying degrees of support for the huge variety of fields found in real-world EXIF files.
  
  when editing camera data in Photoshop it doesn't edit EXIF fields -
+
[http://www.sno.phy.queensu.ca/~phil/exiftool/ ExifTool] is free software that allows manipulation of EXIF and related data in many different kinds of files. ExifTool is one of the most comprehensive EXIF editors available, and continues to grow the number and depth of support for undocumented EXIF metadata, as well as adding support for other (non-EXIF) file formats and metadata structures.
  it stores any changes in XMP, which would explain why other tools
+
  aren't reading the EXIF properly (it's not actually there!).
+
 
+
  The best solution is to use ExifTool to copy your camera data
+
  from a source file into any files that need it... it's a very
+
  simple operation to batch in either EXIFUtils or ExifTool.
+
  
 
[[photomolo]] is a free tool for lossless rotation of [[JPEG]] images and updating the '''EXIF''' tag appropriately.
 
[[photomolo]] is a free tool for lossless rotation of [[JPEG]] images and updating the '''EXIF''' tag appropriately.
 
[[Category:Glossary]]
 
[[Category:Glossary]]

Revision as of 20:35, 19 June 2006

EXIF stands for Exchangeable Image File Format. It allows camera, lens, exposure information, image description, copyright, etc. to be embedded in standardized fields within JFIF (JPEG) or TIFF image files. EXIF is a de facto standard promoted by the camera industry as a means to store metadata recorded by a digital camera, and is not intended as a general-purpose metadata storage mechanism. XMP is a more generalized format for storing arbitrary metadata in a variety of media file formats.

For more detailed information, see the home page for ExifTool, especially the tables of ExifTool Tag Names and EXIF Tags.

As you'll note from the ExifTool pages above, there are many redundant fields due to different manufacturers defining unique fields for semantically identical information, as well as fields which are intended to store manufacturer-specific metadata. Many of these fields are undocumented, at least as far as the public is concerned, and so there is much energy in the industry devoted to decoding these unique fields, their semantics and their constraints.

While EXIF is not generally intended to be user editable, there are a large number of tools that are capable of editing EXIF metadata with varying degrees of support for the huge variety of fields found in real-world EXIF files.

ExifTool is free software that allows manipulation of EXIF and related data in many different kinds of files. ExifTool is one of the most comprehensive EXIF editors available, and continues to grow the number and depth of support for undocumented EXIF metadata, as well as adding support for other (non-EXIF) file formats and metadata structures.

photomolo is a free tool for lossless rotation of JPEG images and updating the EXIF tag appropriately.