Tag Image File Format/Electronic Photography (TIFF/EP) is a digital imagefile format standard – ISO 12234-2, titled "Electronic still-picture imaging – Removable memory – Part 2: TIFF/EP image data format". This is different from the Tagged Image File Format, which is a standard administered by Adobe currently called "TIFF, Revision 6.0 Final – June 3, 1992".
The TIFF/EP standard is based on a subset of the AdobeTIFF standard, and a subset of the JEITAExif standard, with some differences and extensions.
One of the uses of TIFF/EP is as a raw image format. A characteristic of most digital cameras (but excluding those using the Foveon X3 sensor or similar, hence especially Sigma cameras) is that they use a color filter array (CFA). Software processing a raw image format for such a camera needs information about the configuration of the color filter array, so that the raw image can identify separate data from the individual sites of the sensor. Ideally this information is held within the raw image file itself, and TIFF/EP uses the tags that begin "CFA", CFARepeatPatternDim and CFAPattern, which are only relevant for raw images.
This standard has not been adopted by most camera manufacturers – Exif/DCF is the current industry standard file organisation system which uses the Exchangeable image file format. However, TIFF/EP provided a basis for the raw image formats of a number of cameras. One example is Nikon's NEF raw file format, which uses the tag TIFF/EPStandardID (with value 1.0.0.0).[1] Adobe's DNG (Digital Negative) raw file format was based on TIFF/EP, and the DNG specification states "DNG... is compatible with the TIFF-EP standard".[2] Several cameras use DNG as their raw file format, so in that limited sense they use TIFF/EP too.[3]
There are no major departures by the TIFF/EP standard from the TIFF standard, except that many of the TIFF tags are ignored.
The TIFF/EP standard does however have a few notable differences from the Exif standards:
All tags used by TIFF/EP which are defined by the Exif standard to reside within the Exif Sub-IFD now reside directly under the first (main) TIFF IFD.
The Exif IFD Sub-IFD, Interoperability Sub-IFD and the MakerNote Tag have all been omitted.
Unlike the TIFF 6.0 standard, the TIFF/EP standard defines a method of dealing with thumbnail images. This however is different from the method that is used in the Exif standard.
Several tags defined by the Exif standard have been re-defined in the TIFF/EP standard – see table below.
TIFF/EP Tag#
Exif Tag#
Tag Name
920B16
A20B16
FlashEnergy
920C16
A20C16
SpatialFrequencyResponse
920E16
A20E16
FocalPlaneXResolution
920F16
A20F16
FocalPlaneYResolution
921016
A21016
FocalPlaneResolutionUnit
921416
A21416
SubjectLocation
921516
A21516
ExposureIndex
921716
A21716
SensingMethod
828E16
A30216
CFAPattern
Compression
Images in TIFF/EP files may be stored in uncompressed form, or using JPEG baseline DCT-based lossy compression. TIFF/EP also allows usage of other compression methods, but TIFF/EP readers are not required to decompress these images. All TIFF/EP readers shall support the DCT (lossy) baseline version of the TIFF/JPEG compression method described in TIFF 6.0 Technical note #2. The JPEG compression is indicated using a value of 000716 in the Compression tag-field as a binary value.[4]
There may be more than one image (subfile) in a TIFF 6.0 file. Each subfile is defined by Image File Directory (IFD). If an image compression method is used in TIFF/EP, an uncompressed Baseline TIFF-readable "thumbnail" image (with a reduced-resolution) should also be stored in the 0th IFD of TIFF/EP, to allow the images to be viewed and identified using a Baseline TIFF 6.0 reader. (Note: JPEG compression is not required for Baseline TIFF 6.0 readers.)[4]
TIFF/EP files may optionally use lossless JPEG compression and other JPEG compressions, but TIFF/EP readers are not required to decompress these images. If the lossless JPEG compression is used, the recommended form is lossless sequential DPCM using Huffman coding. TIFF/EP files may also optionally support vendor unique compression, but TIFF/EP readers are only required to open the uncompressed "thumbnail" image that may be present in IFD0. Proprietary compression methods can be used by obtaining a private compression tag value from the TIFF administrator (Adobe).[4]
TIFF/EP complies with the TIFF 6.0 specification. The reason is to maintain compatibility with existing TIFF readers, and to make the adoption of TIFF/EP as easy as possible.
The TIFF Tag 259 (010316) stores the information about the Compression method. Its use is mandatory in TIFF/EP. There is no default value in TIFF/EP, but the tag value shall equal "000116" for the thumbnail IFD. The following is a list of defined TIFF/EP compression schemes:[4]
Shall be supported by TIFF/EP readers; shall be used for the thumbnail IFD; may be used for images
000716
TIFF/JPEG compression ('new-style' JPEG)
TIFF/EP readers are only required to support Baseline DCT JPEG method
Other values > 7FFF16
Vendor unique compression methods
TIFF/EP readers are not required to support these compressions
Timeline for development and revision
Dates limited to publicly available sources:
Date
Event
1998
A DIS (Draft International Standard) of TIFF/EP was available from ISO.[5][6]
2001
TIFF/EP was ratified and published by ISO as an International Standard.[7]
2006
TIFF/EP began its 5-year revision cycle by ISO Working Group WG18.[8]
2007 (March)
An email from WG18 stated "The Adobe DNG format was derived from this standard and the group has Adobe's permission to incorporate modifications and developments made for DNG in the new standard".[9]
2008 (May)
There was further confirmation that Adobe had offered the DNG specification to ISO as part of ISO's TIFF/EP standard.[10]
2008 (September)
Minutes of ISO/TC 130/WG2 — Prepress Data Exchange, 37th Meeting: "WG 18 is revising the two-part standard (ISO 12234), which addresses digital camera removable memory. The revision of Part 1 will add JPEG2000; the revision of Part 2 will add DNG into TIFF/EP."[11]
2009 (September)
Minutes of ISO/TC 130/WG2 — Prepress Data Exchange, 39th Meeting: the revision "is comprehensive to support many different use cases, including backward compatibility with current TIFF readers and support of Adobe DNG. There are two interoperability profiles defined: Profile 1 (proposed extension .tif) will provide an intended output-referred interpretation (reproduction color appearance), supporting any color encoding that can be supported using an ICC profile, including output-referred, scene-referred, and demosaiced camera raw... Profile 2 (proposed extension .dng, if Adobe is in agreement) is intended for camera raw images, including un-demosaiced images... This format will be similar to DNG 1.3, which serves as the starting point for development."[12]
^I3A (International Imaging Industry Association):
^Web archive of widely distributed email: Forwarded Message from a member of the ISO TC42 (technical committee for photography) working group 18 (electronic imaging) standards group
^DPReview: Adobe seeks International recognition for DNG
^NPES: Minutes of ISO/TC 130/WG2, 37th Meeting, see 14f
^NPES: Minutes of ISO/TC 130/WG2, 39th Meeting, see 14f
External links
ISO 12234-2:2001 Electronic still-picture imaging – Removable memory – Part 2: TIFF/EP image data format
Link to a copy of the 1998 draft standard
March 05, 2023
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For the standard TIFF file format see Tagged Image File Format Tag Image File Format Electronic Photography TIFF EP is a digital image file format standard ISO 12234 2 titled Electronic still picture imaging Removable memory Part 2 TIFF EP image data format This is different from the Tagged Image File Format which is a standard administered by Adobe currently called TIFF Revision 6 0 Final June 3 1992 TIFF EPFilename extension tiff tifInternet media typeimage tiffDeveloped byInternational Organization for StandardizationInitial release2001 2001 Latest releaseISO 12234 2 20012001 22 years ago 2001 Type of formatImage file formatsContainer forMetadataExtended fromTIFF and ExifExtended toDigital Negative SpecificationStandardISO 12234 2The TIFF EP standard is based on a subset of the Adobe TIFF standard and a subset of the JEITA Exif standard with some differences and extensions One of the uses of TIFF EP is as a raw image format A characteristic of most digital cameras but excluding those using the Foveon X3 sensor or similar hence especially Sigma cameras is that they use a color filter array CFA Software processing a raw image format for such a camera needs information about the configuration of the color filter array so that the raw image can identify separate data from the individual sites of the sensor Ideally this information is held within the raw image file itself and TIFF EP uses the tags that begin CFA CFARepeatPatternDim and CFAPattern which are only relevant for raw images This standard has not been adopted by most camera manufacturers Exif DCF is the current industry standard file organisation system which uses the Exchangeable image file format However TIFF EP provided a basis for the raw image formats of a number of cameras One example is Nikon s NEF raw file format which uses the tag TIFF EPStandardID with value 1 0 0 0 1 Adobe s DNG Digital Negative raw file format was based on TIFF EP and the DNG specification states DNG is compatible with the TIFF EP standard 2 Several cameras use DNG as their raw file format so in that limited sense they use TIFF EP too 3 Contents 1 New Tags 2 Differences from TIFF and Exif 3 Compression 4 Timeline for development and revision 5 See also 6 References 7 External linksNew Tags EditThe following new tags are defined in the TIFF EP standard all to be placed in the first TIFF Image File Directory IFD TIFF EP Tag Tag Name014A16 SubIFDs015B16 JPEGTables828D16 CFARepeatPatternDim828F16 BatteryLevel83BB16 IPTC NAA877316 InterColorProfile882916 Interlace882A16 TimeZoneOffset882B16 SelfTimerMode920D16 Noise921116 ImageNumber921216 SecurityClassification921316 ImageHistory921616 TIFF EPStandardIDDifferences from TIFF and Exif EditThere are no major departures by the TIFF EP standard from the TIFF standard except that many of the TIFF tags are ignored The TIFF EP standard does however have a few notable differences from the Exif standards All tags used by TIFF EP which are defined by the Exif standard to reside within the Exif Sub IFD now reside directly under the first main TIFF IFD The Exif IFD Sub IFD Interoperability Sub IFD and the MakerNote Tag have all been omitted Unlike the TIFF 6 0 standard the TIFF EP standard defines a method of dealing with thumbnail images This however is different from the method that is used in the Exif standard Several tags defined by the Exif standard have been re defined in the TIFF EP standard see table below TIFF EP Tag Exif Tag Tag Name920B16 A20B16 FlashEnergy920C16 A20C16 SpatialFrequencyResponse920E16 A20E16 FocalPlaneXResolution920F16 A20F16 FocalPlaneYResolution921016 A21016 FocalPlaneResolutionUnit921416 A21416 SubjectLocation921516 A21516 ExposureIndex921716 A21716 SensingMethod828E16 A30216 CFAPatternCompression EditImages in TIFF EP files may be stored in uncompressed form or using JPEG baseline DCT based lossy compression TIFF EP also allows usage of other compression methods but TIFF EP readers are not required to decompress these images All TIFF EP readers shall support the DCT lossy baseline version of the TIFF JPEG compression method described in TIFF 6 0 Technical note 2 The JPEG compression is indicated using a value of 000716 in the Compression tag field as a binary value 4 There may be more than one image subfile in a TIFF 6 0 file Each subfile is defined by Image File Directory IFD If an image compression method is used in TIFF EP an uncompressed Baseline TIFF readable thumbnail image with a reduced resolution should also be stored in the 0th IFD of TIFF EP to allow the images to be viewed and identified using a Baseline TIFF 6 0 reader Note JPEG compression is not required for Baseline TIFF 6 0 readers 4 TIFF EP files may optionally use lossless JPEG compression and other JPEG compressions but TIFF EP readers are not required to decompress these images If the lossless JPEG compression is used the recommended form is lossless sequential DPCM using Huffman coding TIFF EP files may also optionally support vendor unique compression but TIFF EP readers are only required to open the uncompressed thumbnail image that may be present in IFD0 Proprietary compression methods can be used by obtaining a private compression tag value from the TIFF administrator Adobe 4 TIFF EP complies with the TIFF 6 0 specification The reason is to maintain compatibility with existing TIFF readers and to make the adoption of TIFF EP as easy as possible The TIFF Tag 259 010316 stores the information about the Compression method Its use is mandatory in TIFF EP There is no default value in TIFF EP but the tag value shall equal 000116 for the thumbnail IFD The following is a list of defined TIFF EP compression schemes 4 See also TIFF TIFF Compression Tag TIFF EP Compression Tag values Tag value Compression scheme Description000116 Uncompressed Shall be supported by TIFF EP readers shall be used for the thumbnail IFD may be used for images000716 TIFF JPEG compression new style JPEG TIFF EP readers are only required to support Baseline DCT JPEG methodOther values gt 7FFF16 Vendor unique compression methods TIFF EP readers are not required to support these compressionsTimeline for development and revision EditDates limited to publicly available sources Date Event1998 A DIS Draft International Standard of TIFF EP was available from ISO 5 6 2001 TIFF EP was ratified and published by ISO as an International Standard 7 2006 TIFF EP began its 5 year revision cycle by ISO Working Group WG18 8 2007 March An email from WG18 stated The Adobe DNG format was derived from this standard and the group has Adobe s permission to incorporate modifications and developments made for DNG in the new standard 9 2008 May There was further confirmation that Adobe had offered the DNG specification to ISO as part of ISO s TIFF EP standard 10 2008 September Minutes of ISO TC 130 WG2 Prepress Data Exchange 37th Meeting WG 18 is revising the two part standard ISO 12234 which addresses digital camera removable memory The revision of Part 1 will add JPEG2000 the revision of Part 2 will add DNG into TIFF EP 11 2009 September Minutes of ISO TC 130 WG2 Prepress Data Exchange 39th Meeting the revision is comprehensive to support many different use cases including backward compatibility with current TIFF readers and support of Adobe DNG There are two interoperability profiles defined Profile 1 proposed extension tif will provide an intended output referred interpretation reproduction color appearance supporting any color encoding that can be supported using an ICC profile including output referred scene referred and demosaiced camera raw Profile 2 proposed extension dng if Adobe is in agreement is intended for camera raw images including un demosaiced images This format will be similar to DNG 1 3 which serves as the starting point for development 12 See also EditTagged Image File Format TIFF Exchangeable image file format Exif Design rule for Camera File system International Organization for Standardization List of ISO standardsReferences Edit Pearson Barry What is in a raw file UK Adobe DNG 1 3 0 0 Specification June 2009 scroll down a bit Pearson Barry Products from camera manufacturers that use DNG in some way UK a b c d ISO DIS 12234 2 Photography Electronic still picture imaging Removable memory Part 2 Image data format TIFF EP PDF 1998 archived from the original on February 12 2006 retrieved 2011 03 08 a href Template Citation html title Template Citation citation a CS1 maint unfit URL link Link to a copy of the 1998 draft standard PDF DIS PDF draft standard UK Barry Pearson 2000 archived from the original PDF on 2008 11 20 ISO ISO 12234 2 2001 I3A International Imaging Industry Association WG18 Ad Hoc groups and JWG 20 22 23 Meet in Tokyo Web archive of widely distributed email Forwarded Message from a member of the ISO TC42 technical committee for photography working group 18 electronic imaging standards group DPReview Adobe seeks International recognition for DNG NPES Minutes of ISO TC 130 WG2 37th Meeting see 14f NPES Minutes of ISO TC 130 WG2 39th Meeting see 14fExternal links EditISO 12234 2 2001 Electronic still picture imaging Removable memory Part 2 TIFF EP image data format Link to a copy of the 1998 draft standard Retrieved from https en wikipedia org w index php title TIFF EP amp oldid 1134944965, wikipedia, wiki, book, books, library,
