mirror of https://github.com/GNOME/gimp.git
98 lines
2.2 KiB
Plaintext
98 lines
2.2 KiB
Plaintext
|
How GIMP should handle EXIF data
|
||
|
|
|
||
|
|
Bill Skaggs 1/2/05
|
||
|
|
|
||
|
|
This is a summary of how an image editing program is supposed to
|
||
|
|
handle each of the EXIF fields, according to the EXIF specs. Note
|
||
|
|
that this expresses my understanding based on a quick reading, and
|
||
|
|
should not be taken as gospel. For details on the contents of each of
|
||
|
|
these fields, consult the formal EXIF specifications, available from
|
||
|
|
http://www.exif.org/specifications.html.
|
||
|
|
|
||
|
|
(Note: according to the EXIF specs, an EXIF jpeg file must have a name
|
||
|
|
that is ASCII, in 8.3 format, with extension .JPG, but of course we
|
||
|
|
are not going to enforce this.)
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Fields that should be used to set up the GIMP image when an EXIF file
|
||
|
|
is loaded, either by using them to configure the image (e.g.,
|
||
|
|
orientation), or by placing them in parasites that can be accessed by
|
||
|
|
non-exif-aware functions.
|
||
|
|
|
||
|
|
Orientation
|
||
|
|
XResolution
|
||
|
|
YResolution
|
||
|
|
ResolutionUnit
|
||
|
|
ImageDescription
|
||
|
|
Artist
|
||
|
|
Copyright
|
||
|
|
Colorspace
|
||
|
|
ComponentsConfiguration
|
||
|
|
UserComment
|
||
|
|
SubjectArea
|
||
|
|
SubjectLocation
|
||
|
|
ImageUniqueID
|
||
|
|
PixelXDimension
|
||
|
|
PixelYDimension
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Fields that should be modified by GIMP when an EXIF jpeg file is
|
||
|
|
saved. A letter "M" indicates fields whose presence is mandatory
|
||
|
|
according to the spec.
|
||
|
|
|
||
|
|
Orientation
|
||
|
|
XResolution (M)
|
||
|
|
YResolution (M)
|
||
|
|
ResolutionUnit (M)
|
||
|
|
Software
|
||
|
|
DateTime
|
||
|
|
ImageDescription
|
||
|
|
Artist
|
||
|
|
Colorspace (M)
|
||
|
|
PixelXDimension (M)
|
||
|
|
PixelYDimension (M)
|
||
|
|
ComponentsConfiguration (M)
|
||
|
|
UserComment
|
||
|
|
SubsecTime
|
||
|
|
SubjectArea
|
||
|
|
SubjectLocation
|
||
|
|
FileSource
|
||
|
|
ImageUniqueID
|
||
|
|
thumbnail Compression (M)
|
||
|
|
thumbnail XResolution (M)
|
||
|
|
thumbnail YResolution (M)
|
||
|
|
thumbnail JPEGInterchangeFormat (M)
|
||
|
|
thumbnail JPEGInterchangeFormatLength (M)
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Fields that should be used and saved related to color management:
|
||
|
|
|
||
|
|
TransferFunction
|
||
|
|
WhitePoint
|
||
|
|
PrimaryChromaticity
|
||
|
|
YCbCrCoefficients
|
||
|
|
ReferenceBlackWhite
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Fields that should be deleted if they exist when saving a file as
|
||
|
|
jpeg, because they only apply to uncompressed (TIFF) data. This
|
||
|
|
applies both to the main image and to the thumbnail, if there is one.
|
||
|
|
|
||
|
|
ImageWidth
|
||
|
|
ImageLength
|
||
|
|
BitsPerSample
|
||
|
|
Compression
|
||
|
|
SamplesPerPixel
|
||
|
|
PhotometricInterpretation
|
||
|
|
StripOffsets
|
||
|
|
PlanarConfiguration
|
||
|
|
YCbCrSubSampling
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Any field not mentioned here should be passed through unchanged.
|