TIFF/EP

Tag Image File Format/Electronic Photography (TIFF/EP) is a digital image file format standardISO 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 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]

TIFF/EP
Filename extension.tiff, .tif
Developed byInternational Organization for Standardization
Initial release2001
Latest release
ISO 12234-2:2001
(2001)
Type of formatImage file formats
Container forMetadata
Extended fromTIFF and Exif
Extended toDigital Negative Specification
StandardISO 12234-2

New Tags

The 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 Name
014A16 SubIFDs
015B16 JPEGTables
828D16 CFARepeatPatternDim
828F16 BatteryLevel
83BB16 IPTC/NAA
877316 InterColorProfile
882916 Interlace
882A16 TimeZoneOffset
882B16 SelfTimerMode
920D16 Noise
921116 ImageNumber
921216 SecurityClassification
921316 ImageHistory
921616 TIFF/EPStandardID

Differences from TIFF and Exif

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]

TIFF/EP Compression Tag values
Tag value Compression scheme Description
000116 Uncompressed 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]

See also

References

  1. ^ Pearson, Barry, What is in a raw file?, UK.
  2. ^ Adobe: DNG 1.3.0.0 Specification (June 2009) (scroll down a bit)
  3. ^ Pearson, Barry, Products from camera manufacturers that use DNG in some way, UK.
  4. ^ 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 2011-03-08CS1 maint: Unfit url (link)
  5. ^ Link to a copy of the 1998 draft standard
  6. ^ DIS (PDF) (draft standard), UK: Barry Pearson, 2000, archived from the original (PDF) on 2008-11-20.
  7. ^ ISO: ISO 12234-2:2001
  8. ^ I3A (International Imaging Industry Association): WG18, Ad Hoc groups and JWG 20/22/23 Meet in Tokyo
  9. ^ 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
  10. ^ DPReview: Adobe seeks International recognition for DNG
  11. ^ NPES: Minutes of ISO/TC 130/WG2, 37th Meeting, see 14f
  12. ^ NPES: Minutes of ISO/TC 130/WG2, 39th Meeting, see 14f

External links

CPT (file format)

The CPT file format is a graphics file format used by some versions of Corel Photo Paint.

It is also possible to open CPT version 6 files with IrfanView, but not with Paint Shop Pro (although it is from Corel). CPT version 6 is an almost identical copy of the TIFF format, whereas since Corel Photo-Paint 7.0 (released in 1997), this was deprecated for a new proprietary format (known as CPT7), however the user can still export the older TIFF-based CPT6 files. Chasys Draw IES can open CPT7 files as well as CPT8 and the latest CPT9; this support is available as from Chasys Draw IES version 4.58.01 [1].

Corel Photo Paint is not released as a standalone program. It is part of the Corel Draw Graphics Suite, available only for Windows.

The .cpt extension is also used for files encrypted using ccrypt, and also for screen captures in the video game Tekken Tag Tournament (PlayStation 2), which are saved to the Memory Card.

CinemaDNG

CinemaDNG is the result of an Adobe-led initiative to define an industry-wide open file format for digital cinema files. CinemaDNG caters for sets of movie clips, each of which is a sequence of raw video images, accompanied by audio and metadata. CinemaDNG supports stereoscopic cameras and multiple audio channels. CinemaDNG specifies directory structures containing one or more video clips, and specifies requirements and constraints for the open format files, (DNG, TIFF, XMP, and/or MXF), within those directories, that contain the content of those clips.CinemaDNG is different from the Adobe DNG (Digital Negative) format that is primarily used as a raw image format for still cameras. However, each CinemaDNG image is encoded using that DNG image format. The image stream can then be stored in one of two formats: either as video essence using frame-based wrapping in an MXF file, or as a sequence of DNG image files in a specified file directory. Each clip uses just one of these formats, but the set of clips in a movie may use both.

Comparison of graphics file formats

This is a comparison of image file formats.

Digital Negative

Digital Negative (DNG) is a patented, open, lossless raw image format written by Adobe used for digital photography. Adobe's license allows use without cost on the condition that the licensee prominently displays text saying it is licensed from Adobe in source and documentation, and that the license may be revoked if the licensee brings any patent action against Adobe or its affiliates related to the reading or writing of files that comply with the DNG Specification. It was launched on September 27, 2004. The launch was accompanied by the first version of the DNG specification, plus various products, including a free-of-charge DNG converter utility. All Adobe photo manipulation software (such as Adobe Photoshop and Adobe Lightroom) released since the launch supports DNG.DNG is based on the TIFF/EP standard format, and mandates significant use of metadata. Use of the file format is royalty-free; Adobe has published a license allowing anyone to exploit DNG, and has also stated that there are no known intellectual property encumbrances or license requirements for DNG. Adobe stated that if there were a consensus that DNG should be controlled by a standards body, they were open to the idea. Adobe has submitted DNG to ISO for incorporation into their revision of TIFF/EP.

Exif

Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies the formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other systems handling image and sound files recorded by digital cameras. The specification uses the following existing file formats with the addition of specific metadata tags: JPEG discrete cosine transform (DCT) for compressed image files, TIFF Rev. 6.0 (RGB or YCbCr) for uncompressed image files, and RIFF WAV for audio files (Linear PCM or ITU-T G.711 μ-Law PCM for uncompressed audio data, and IMA-ADPCM for compressed audio data). It is not used in JPEG 2000 or GIF.

This standard consists of the Exif image file specification and the Exif audio file specification.

G.723

G.723 is an ITU-T standard speech codec using extensions of G.721 providing voice quality covering 300 Hz to 3400 Hz using Adaptive Differential Pulse Code Modulation (ADPCM) to 24 and 40 kbit/s for digital circuit multiplication equipment (DCME) applications. The standard G.723 is obsolete and has been superseded by G.726.

Note that this is a completely different codec from G.723.1.

H.323

H.323 is a recommendation from the ITU Telecommunication Standardization Sector (ITU-T) that defines the protocols to provide audio-visual communication sessions on any packet network. The H.323 standard addresses call signaling and control, multimedia transport and control, and bandwidth control for point-to-point and multi-point conferences.It is widely implemented by voice and videoconferencing equipment manufacturers, is used within various Internet real-time applications such as GnuGK and NetMeeting and is widely deployed worldwide by service providers and enterprises for both voice and video services over IP networks.

It is a part of the ITU-T H.32x series of protocols, which also address multimedia communications over ISDN, the PSTN or SS7, and 3G mobile networks.

H.323 call signaling is based on the ITU-T Recommendation Q.931 protocol and is suited for transmitting calls across networks using a mixture of IP, PSTN, ISDN, and QSIG over ISDN. A call model, similar to the ISDN call model, eases the introduction of IP telephony into existing networks of ISDN-based PBX systems, including transitions to IP-based PBXs.

Within the context of H.323, an IP-based PBX might be a gatekeeper or other call control element which provides service to telephones or videophones. Such a device may provide or facilitate both basic services and supplementary services, such as call transfer, park, pick-up, and hold.

List of abbreviations in photography

During most of the 20th century photography depended mainly upon the photochemical technology of silver halide emulsions on glass plates or roll film. Early in the 21st century this technology was displaced by the electronic technology of digital cameras. The development of digital image sensors, microprocessors, memory cards, miniaturised devices and image editing software enabled these cameras to offer their users a much wider range of operating options than was possible with the older silver halide technology. This has led to a proliferation of new abbreviations, acronyms and initialisms. The commonest of these are listed below. Some are used in related fields of optics and electronics but many are specific to digital photography.

List of file formats

This is a list of file formats used by computers, organized by type. Filename extensions are usually noted in parentheses if they differ from the file format name or abbreviation. Many operating systems do not limit filenames to one extension shorter than 4 characters, as was common with some operating systems that supported the File Allocation Table (FAT) file system. Examples of operating systems that do not impose this limit include Unix-like systems, and Microsoft Windows NT, 95, 98, and ME which have no three character limit on extensions for 32-bit or 64-bit applications on file systems other than pre-Windows 95 and Windows NT 3.5 versions of the FAT file system. Some filenames are given extensions longer than three characters. While MS-DOS and NT always see the final period in a filename as an extension, in UNIX-like systems, the final period doesn't necessarily mean the text afterward is the extension.Some file formats, such as .txt, may be listed multiple times.

Mathematical joke

A mathematical joke is a form of humor which relies on aspects of mathematics or a stereotype of mathematicians to derive humor. The humor may come from a pun, or from a double meaning of a mathematical term, or from a lay person's misunderstanding of a mathematical concept. Mathematician and author John Allen Paulos in his book Mathematics and Humor described several ways that mathematics, generally considered a dry, formal activity, overlaps with humor, a loose, irreverent activity: both are forms of "intellectual play"; both have "logic, pattern, rules, structure"; and both are "economical and explicit".Some performers combine mathematics and jokes to entertain and/or teach math.

Humor of mathematicians may be classified into the esoteric and exoteric categories. Esoteric jokes rely on the intrinsic knowledge of mathematics and its terminology. Exoteric jokes are intelligible to the outsiders, and most of them compare mathematicians with representatives of other disciplines or with common folk.

Mp3PRO

mp3PRO is an unmaintained proprietary audio compression codec that combines the MP3 audio format with the spectral band replication (SBR) compression method. At the time it was developed it could reduce the size of a stereo MP3 by as much as 50% while maintaining the same relative quality. This works, fundamentally, by discarding the higher half of the frequency range and algorithmically replicating that information while decoding.

The technology behind SBR was developed by the former Swedish company Coding Technologies AB (acquired by Dolby Laboratories in 2007) in the late 1990s. It was included in their MPEG-2 AAC derived codec aacPlus, which would later be standardized as MPEG-4 HE-AAC. Thomson Multimedia (now Technicolor SA) licensed the technology and used it to extend the MP3 format, for which they held patents, hoping to also extend its profitable lifetime. This was released as mp3PRO in 2001.It was originally claimed that mp3PRO files were compatible with existing MP3 decoders, and that the SBR data could simply be ignored. The reality was that MP3 players lacking specific mp3PRO decoding capability experienced a significant reduction in audio quality when playing mp3PRO files as only the lower half of the original frequency range is available.mp3PRO development has been abandoned. The format was never standardized and there is no publicly available reference source code or documentation in existence. A very old software encoder/player exists, but is not maintained. Nero's Soundtrax application, bundled in the Nero Multimedia Suite, is capable of encoding and decoding this format into several others. Some versions of the outdated MusicMatch Jukebox player were able to decode and encode this format, too. In the early 2000s, mp3PRO was usable in several portable music players and in popular music software, but its market share has deteriorated rapidly. The codec itself is largely surpassed in quality and efficiency, as well as device and application support, by modern codecs like AAC and its HE-AAC variants which employ the same SBR method.

Picture Transfer Protocol

Picture Transfer Protocol (PTP) is a protocol developed by the International Imaging Industry Association to allow the transfer of images from digital cameras to computers and other peripheral devices without the need of additional device drivers. The protocol has been standardized as ISO 15740.

It is further standardized for USB by the USB Implementers Forum as the still image capture device class. USB is the default network transport media for PTP devices. USB PTP is a common alternative to the USB mass-storage device class (USB MSC), as a digital camera connection protocol. Some cameras support both modes.

Raw image format

A camera raw image file contains minimally processed data from the image sensor of either a digital camera, or motion picture film scanner, or other image scanner. Raw files are named so because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a raw converter in a wide-gamut internal color space where precise adjustments can be made before conversion to a "positive" file format such as TIFF or JPEG for storage, printing, or further manipulation. This often encodes the image in a device-dependent color space. There are dozens, if not hundreds, of raw formats in use by different models of digital equipment (like cameras or film scanners).

TIFF

Tagged Image File Format, abbreviated TIFF or TIF, is a computer file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word processing, optical character recognition, image manipulation, desktop publishing, and page-layout applications. The format was created by Aldus Corporation for use in desktop publishing. It published the latest version 6.0 in 1992, subsequently updated with an Adobe Systems copyright after the latter acquired Aldus in 1994. Several Aldus or Adobe technical notes have been published with minor extensions to the format, and several specifications have been based on TIFF 6.0, including TIFF/EP (ISO 12234-2), TIFF/IT (ISO 12639), TIFF-F (RFC 2306) and TIFF-FX (RFC 3949).

Raster
Raw
Vector
Compound
Metadata
ISO standards by standard number
1–9999
10000–19999
20000+

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