Tag Image File Format, abbreviated TIFF or TIF, is an

image file format An Image file format is a file format for a digital image. There are many formats that can be used, such as JPEG, Portable Network Graphics, PNG, and GIF. Most formats up until 2022 were for storing 2D images, not 3D ones. The data stored in an ...

for storing

raster graphics upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for ...

images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing,

word processing A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consen ...

optical character recognition Optical character recognition or optical character reader (OCR) is the electronic or mechanical conversion of images of typed, handwritten or printed text into machine-encoded text, whether from a scanned document, a photo of a document, a scen ...

, image manipulation,

desktop publishing Desktop publishing (DTP) is the creation of documents using page layout software on a personal ("desktop") computer. It was first used almost exclusively for print publications, but now it also assists in the creation of various forms of online c ...

, and page-layout applications. The format was created by the

Aldus Corporation Aldus Corporation was an American software company best known for its pioneering desktop publishing (DTP) software. PageMaker, the company's most well-known product, ushered in the modern era of desktop computers such as the Macintosh seeing ...

for use in desktop publishing. It published the latest version 6.0 in 1992, subsequently updated with an

Adobe Systems Adobe Inc. ( ), originally called Adobe Systems Incorporated, is an American multinational computer software company incorporated in Delaware and headquartered in San Jose, California. It has historically specialized in software for the crea ...

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).

History

TIFF was created as an attempt to get desktop scanner vendors of the mid-1980s to agree on a common scanned image file format, in place of a multitude of

proprietary format A proprietary file format is a file format of a company, organization, or individual that contains data that is ordered and stored according to a particular encoding-scheme, designed by the company or organization to be secret, such that the decodi ...

s. In the beginning, TIFF was only a

binary image A binary image is one that consists of pixels that can have one of exactly two colors, usually black and white. Binary images are also called ''bi-level'' or ''two-level'', Pixelart made of two colours is often referred to as ''1-Bit'' or ''1b ...

format (only two possible values for each pixel), because that was all that desktop scanners could handle. As scanners became more powerful, and as desktop computer disk space became more plentiful, TIFF grew to accommodate

grayscale In digital photography, computer-generated imagery, and colorimetry, a grayscale image is one in which the value of each pixel is a single sample representing only an ''amount'' of light; that is, it carries only intensity information. Graysca ...

images, then color images. Today, TIFF, along with

JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...

and PNG, is a popular format for deep-color images. The first version of the TIFF specification was published by the

in the autumn of 1986 after two major earlier draft releases. It can be labeled as Revision 3.0. It was published after a series of meetings with various scanner manufacturers and software developers. In April 1987 Revision 4.0 was released and it contained mostly minor enhancements. In October 1988 Revision 5.0 was released and it added support for palette color images and LZW compression.TIFF Revision 6.0 Final — June 3, 1992
Retrieved on 2020-06-06 TIFF is a complex format, defining many tags of which typically only a few are used in each file. This led to implementations supporting many varying subsets of the format, a situation that gave rise to the joke that TIFF stands for ''Thousands of Incompatible File Formats''. This problem was addressed in revision 6.0 of the TIFF specification (June 1992) by introducing a distinction between ''Baseline TIFF'' (which all implementations were required to support) and ''TIFF Extensions'' (which are optional). Additional extensions are defined in two supplements to the specification, published September 1995 and March 2002TIFF Specification Supplement 2
Retrieved 2022-06-29 respectively.

Overview

A TIFF file contains one ''or several'' images, termed ''subfiles'' in the specification. The basic use-case for having multiple subfiles is to encode a multipage

telefax Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...

in a single file, but it is also allowed to have different subfiles be different variants of the same image, for example scanned at different resolutions. Rather than being a continuous range of bytes in the file, each subfile is a data structure whose top-level entity is called an ''image file directory'' (IFD). Baseline TIFF readers are only required to make use of the first subfile, but each IFD has a field for linking to a next IFD. The IFDs are where the ''tags'' for which TIFF is named are located. Each IFD contains one or several ''entries'', each of which is identified by its tag. The tags are arbitrary 16-bit numbers; their symbolic names such as ImageWidth often used in discussions of TIFF data do not appear explicitly in the file itself. Each IFD entry has an associated ''value'', which may be decoded based on general rules of the format, but it depends on the tag what that value then ''means''. There may within a single IFD be no more than one entry with any particular tag. Some tags are for linking to the actual image data, other tags specify how the image data should be interpreted, and still other tags are used for image

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

. TIFF images are made up of rectangular grids of pixels. The two axes of this geometry are termed horizontal (or X, or width) and vertical (or Y, or length). Horizontal and vertical

resolution Resolution(s) may refer to: Common meanings * Resolution (debate), the statement which is debated in policy debate * Resolution (law), a written motion adopted by a deliberative body * New Year's resolution, a commitment that an individual mak ...

need not be equal (since in a telefax they typically would not be equal). A baseline TIFF image divides the vertical range of the image into one or several ''strips'', which are encoded (in particular: compressed) separately. Historically this served to facilitate TIFF readers (such as fax machines) with limited capacity to store uncompressed data — one strip would be decoded and then immediately printed — but the present specification motivates it by “increased editing flexibility and efficient I/O buffering”. A TIFF extension provides the alternative of ''tiled'' images, in which case both the horizontal and the vertical ranges of the image are decomposed into smaller units. An example of these things, which also serves to give a flavor of how tags are used in the TIFF encoding of images, is that a striped TIFF image would use tags 273 (StripOffsets), 278 (RowsPerStrip), and 279 (StripByteCounts). The StripOffsets point to the blocks of image data, the StripByteCounts say how long each of these blocks are (as stored in the file), and RowsPerStrip says how many rows of pixels there are in a strip; the latter is required even in the case of having just one strip, in which case it merely duplicates the value of tag 257 (ImageLength). A tiled TIFF image instead uses tags 322 (TileWidth), 323 (TileLength), 324 (TileOffsets), and 325 (TileByteCounts). The pixels within each strip or tile appear in

row-major In computing, row-major order and column-major order are methods for storing multidimensional arrays in linear storage such as random access memory. The difference between the orders lies in which elements of an array are contiguous in memory. In ...

order, top to bottom and left to right. The data for one pixel is made up of one or several ''samples''; for example an

RGB The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...

image would have one Red sample, one Green sample, and one Blue sample per pixel, whereas a greyscale or palette color image only has one sample per pixel. TIFF allows for both

additive Additive may refer to: Mathematics * Additive function, a function in number theory * Additive map, a function that preserves the addition operation * Additive set-functionn see Sigma additivity * Additive category, a preadditive category with f ...

(e.g. RGB,

RGBA RGBA stands for red green blue alpha. While it is sometimes described as a color space, it is actually a three-channel RGB color model supplemented with a fourth ''alpha channel''. Alpha indicates how opaque each pixel is and allows an image to ...

) and subtractive (e.g.

CMYK The CMYK color model (also known as process color, or four color) is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. The abbreviation ''CMYK'' refers ...

) color models. TIFF does not constrain the number of samples per pixel (except that there must be enough samples for the chosen color model), nor does it constrain how many bits are encoded for each sample, but baseline TIFF only requires that readers support a few combinations of color model and bit-depth of images. Support for custom sets of samples is very useful for scientific applications; 3 samples per pixel is at the low end of

multispectral imaging Multispectral imaging captures image data within specific wavelength ranges across the electromagnetic spectrum. The wavelengths may be separated by filters or detected with the use of instruments that are sensitive to particular wavelengths, ...

, and

hyperspectral imaging Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifyi ...

may require hundreds of samples per pixel. TIFF supports having all samples for a pixel next to each other within a single strip/tile (PlanarConfiguration = 1) but also different samples in different strips/tiles (PlanarConfiguration = 2). The default format for a sample value is as an unsigned integer, but a TIFF extension allows declaring them as alternatively being signed integers or

IEEE-754 The IEEE Standard for Floating-Point Arithmetic (IEEE 754) is a technical standard for floating-point arithmetic established in 1985 by the Institute of Electrical and Electronics Engineers (IEEE). The standard addressed many problems found in ...

floats, as well as specify a custom range for valid sample values. TIFF images may be uncompressed, compressed using a

lossless compression Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistic ...

scheme, or compressed using a

lossy compression In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...

scheme. The lossless LZW compression scheme has at times been regarded as the standard compression for TIFF, but this is technically a TIFF extension, and the TIFF6 specification notes the patent situation regarding LZW. Compression schemes vary significantly in at what level they process the data: LZW acts on the stream of bytes encoding a strip or tile (without regard to sample structure, bit depth, or row width), whereas the JPEG compression scheme both transforms the sample structure of pixels (switching to a different color model) and encodes pixels in 8×8 blocks rather than row by row. Most data in TIFF files are numerical, but the format supports declaring data as rather being textual, if appropriate for a particular tag. Tags that take textual values include Artist, Copyright, DateTime, DocumentName, InkNames, and Model.

Internet Media Type

The MIME type ''image/tiff'' (defined in RFC 3302) without an application parameter is used for Baseline TIFF 6.0 files or to indicate that it is not necessary to identify a specific subset of TIFF or TIFF extensions. The optional "application" parameter (Example: Content-type: image/tiff; application=foo) is defined for image/tiff to identify a particular subset of TIFF and TIFF extensions for the encoded image data, if it is known. According to RFC 3302, specific TIFF subsets or TIFF extensions used in the application parameter must be published as an RFC.

MIME Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message ...

type ''image/tiff-fx'' (defined in RFC 3949 and RFC 3950) is based on TIFF 6.0 with TIFF Technical Notes TTN1 (Trees) and TTN2 (Replacement TIFF/JPEG specification). It is used for

Internet fax Internet fax, e-fax, or online fax is the use of the internet and internet protocols to send a fax (facsimile), rather than using a standard telephone connection and a fax machine. A distinguishing feature of Internet fax, compared to other Intern ...

compatible with the ITU-T Recommendations for Group 3 black-and-white, grayscale and color

fax Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...

Digital preservation

Adobe holds the copyright on the TIFF specification (aka TIFF 6.0) along with the two supplements that have been published. These documents can be found on the Adobe TIFF Resources page. The

Fax Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer o ...

standard in RFC 3949 is based on these TIFF specifications. TIFF files that strictly use the basic "tag sets" as defined in TIFF 6.0 along with restricting the compression technology to the methods identified in TIFF 6.0 and are adequately tested and verified by multiple sources for all documents being created can be used for storing documents. Commonly seen issues encountered in the content and

document management A document management system (DMS) is usually a computerized system used to store, share, track and manage files or documents. Some systems include history tracking where a log of the various versions created and modified by different users is r ...

industry associated with the use of TIFF files arise when the structures contain proprietary headers, are not properly documented, and/or contain "wrappers" or other containers around the TIFF datasets, and/or include improper compression technologies, or those compression technologies are not properly implemented. Variants of TIFF can be used within

document imaging Document imaging is an information technology category for systems capable of replicating documents commonly used in business. Document imaging systems can take many forms including microfilm, on demand printers, facsimile machines, copiers, multifu ...

and content/document management systems using

CCITT The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

Group IV 2D compression which supports

black-and-white Black-and-white (B&W or B/W) images combine black and white in a continuous spectrum, producing a range of shades of grey. Media The history of various visual media began with black and white, and as technology improved, altered to color. ...

(bitonal,

monochrome A monochrome or monochromatic image, object or palette is composed of one color (or values of one color). Images using only shades of grey are called grayscale (typically digital) or black-and-white (typically analog). In physics, monochrom ...

) images, among other compression technologies that support

color Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associ ...

. When storage capacity and network bandwidth was a greater issue than commonly seen in today's server environments, high-volume storage scanning, documents were scanned in black and white (not in color or in grayscale) to conserve storage capacity. The inclusion of the SampleFormat tag in TIFF 6.0 allows TIFF files to handle advanced pixel data types, including integer images with more than 8 bits per channel and floating point images. This tag made TIFF 6.0 a viable format for scientific image processing where extended precision is required. An example would be the use of TIFF to store images acquired using scientific CCD cameras that provide up to 16 bits per

photosite In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smal ...

of intensity resolution. Storing a sequence of images in a single TIFF file is also possible, and is allowed under TIFF 6.0, provided the rules for multi-page images are followed.

Details

TIFF is a flexible, adaptable file format for handling images and data within a single file, by including the header tags (size, definition, image-data arrangement, applied

image compression Image compression is a type of data compression applied to digital images, to reduce their cost for storage or transmission. Algorithms may take advantage of visual perception and the statistical properties of image data to provide superior r ...

) defining the image's geometry. A TIFF file, for example, can be a container holding

(lossy) and

PackBits PackBits is a fast, simple lossless compression scheme for run-length encoding of data. Apple introduced the PackBits format with the release of MacPaint on the Macintosh computer. This compression scheme can be used in TIFF files. TGA files also ...

(lossless) compressed images. A TIFF file also can include a

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

-based

clipping path A clipping path (or "deep etch") is a closed vector path, or shape, used to cut out a 2D image in image editing software. Anything inside the path will be included after the clipping path is applied; anything outside the path will be omitted fro ...

(outlines, croppings, image frames). The ability to store image data in a

lossless Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistic ...

format makes a TIFF file a useful image archive, because, unlike standard JPEG files, a TIFF file using lossless compression (or none) may be edited and re-saved without losing image quality. This is not the case when using the TIFF as a container holding compressed JPEG. Other TIFF options are

layers Layer or layered may refer to: Arts, entertainment, and media * ''Layers'' (Kungs album) * ''Layers'' (Les McCann album) * ''Layers'' (Royce da 5'9" album) *"Layers", the title track of Royce da 5'9"'s sixth studio album *Layer, a female Maveric ...

and pages. TIFF offers the option of using LZW compression, a lossless data-compression technique for reducing a file's size. Use of this option was limited by patents on the LZW technique until their expiration in 2004. The TIFF 6.0 specification consists of the following parts: * Introduction (contains information about TIFF Administration, usage of Private fields and values, etc.) * Part 1: Baseline TIFF * Part 2: TIFF Extensions * Part 3: Appendices

Part 1: Baseline TIFF

When TIFF was introduced, its extensibility provoked compatibility problems. The flexibility in encoding gave rise to the joke that TIFF stands for ''Thousands of Incompatible File Formats''. To avoid these problems, every TIFF reader was required to read ''Baseline TIFF''. Among other things, Baseline TIFF does not include layers, or compressed JPEG or LZW images. Baseline TIFF is formally known as ''TIFF 6.0, Part 1: Baseline TIFF''. The following is an incomplete list of required Baseline TIFF features:

Multiple subfiles

TIFF readers must be prepared for multiple/multi-page images (subfiles) per TIFF file, although they are not required to actually do anything with images after the first one. There may be more than one Image File Directory (IFD) in a TIFF file. Each IFD defines a subfile. One use of subfiles is to describe related images, such as the pages of a facsimile document. A Baseline TIFF reader is not required to read any IFD beyond the first one.

Strips

A baseline TIFF image is composed of one or more strips. A strip (or band) is a subsection of the image composed of one or more rows. Each strip may be compressed independently of the entire image, and each begins on a byte boundary. If the image height is not evenly divisible by the number of rows in the strip, the last strip may contain fewer rows. If strip definition tags are omitted, the image is assumed to contain a single strip.

Compression

Baseline TIFF readers must handle the following three compression schemes: * No compression *

Group 3 1-Dimensional Modified Huffman RLE *

compression - a form of

run-length encoding Run-length encoding (RLE) is a form of lossless data compression in which ''runs'' of data (sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count, rather than as the original ...

Image types

Baseline TIFF image types are: bilevel, grayscale, palette-color, and RGB full-color images.

Byte order

Every TIFF file begins with a two-

byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

indicator of

byte order In computing, endianness, also known as byte sex, is the order or sequence of bytes of a word of digital data in computer memory. Endianness is primarily expressed as big-endian (BE) or little-endian (LE). A big-endian system stores the most sig ...

: "II" for little-endian (a.k.a. "Intel byte ordering", circa 1980)David Beecher, author of dozens of image processing engines over the last 30 years. Any TIFF file can be viewed with a HEX editor to confirm this. or "MM" for big-endian (a.k.a. "Motorola byte ordering", circa 1980) byte ordering. The next two-byte word contains the format version number, which has always been 42 for every version of TIFF (e.g., TIFF v5.0 and TIFF v6.0). All two-byte words, double words, etc., in the TIFF file are assumed to be in the indicated byte order. The TIFF 6.0 specification states that compliant TIFF readers must support both byte orders (II and MM); writers may use either.

Other TIFF fields

TIFF readers must be prepared to encounter and ignore private fields not described in the TIFF specification. TIFF readers must not refuse to read a TIFF file if optional fields do not exist.

Part 2: TIFF Extensions

Many TIFF readers support tags additional to those in Baseline TIFF, but not every reader supports every extension. As a consequence, Baseline TIFF features became the lowest common denominator for TIFF. Baseline TIFF features are extended in TIFF Extensions (defined in the TIFF 6.0 Part 2 specification) but extensions can also be defined in private tags. The TIFF Extensions are formally known as ''TIFF 6.0, Part 2: TIFF Extensions''. Here are some examples of TIFF extensions defined in TIFF 6.0 specification:

Compression

* CCITT T.4 bi-level encoding * CCITT T.6 bi-level encoding * LZW *

Image types

Images *

YCbCr YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-diffe ...

Images * HalftoneHints * Tiled Images * CIE L*a*b* Images

Image trees

A baseline TIFF file can contain a sequence of images (IFD). Typically, all the images are related but represent different data, such as the pages of a document. In order to explicitly support multiple views of the ''same'' data, the ''SubIFD'' tag was introduced.TIFF Specification Supplement 1
Retrieved 2022-06-29 This allows the images to be defined along a

tree structure A tree structure, tree diagram, or tree model is a way of representing the hierarchical nature of a structure in a graphical form. It is named a "tree structure" because the classic representation resembles a tree, although the chart is gener ...

. Each image can have a sequence of children, each child being itself an image. The typical usage is to provide thumbnails or several versions of an image in different color spaces.

=Tiles

= A TIFF image may also be composed of a number of tiles. All tiles in the same image have the same dimensions and may be compressed independently of the entire image, similar to strips (see above). Tiled images are part of TIFF 6.0, Part 2: TIFF Extensions, so the support for tiled images is not required in Baseline TIFF readers.

Other extensions

According to TIFF 6.0 specification (Introduction), all TIFF files using proposed TIFF extensions that are not approved by Adobe as part of Baseline TIFF (typically for specialized uses of TIFF that do not fall within the domain of publishing or general graphics or picture interchange) should be either not called TIFF files or should be marked some way so that they will not be confused with mainstream TIFF files.

Private tags

Developers can apply for a block of "private tags" to enable them to include their own proprietary information inside a TIFF file without causing problems for file interchange. TIFF readers are required to ignore tags that they do not recognize, and a registered developer's private tags are guaranteed not to clash with anyone else's tags or with the standard set of tags defined in the specification. Private tags are numbered in the range 32,768 and higher. Private tags are reserved for information meaningful only for some organization, or for experiments with a new compression scheme within TIFF. Upon request, the TIFF administrator (currently Adobe) will allocate and register one or more private tags for an organization, to avoid possible conflicts with other organizations. Organizations and developers are discouraged from choosing their own tag numbers arbitrarily, because doing so could cause serious compatibility problems. However, if there is little or no chance that TIFF files will escape a private environment, organizations and developers are encouraged to consider using TIFF tags in the "reusable" 65,000–65,535 range. There is no need to contact Adobe when using numbers in this range.

TIFF Compression Tag

The TIFF Tag 259 (0103₁₆) stores the information about the Compression method. The default value is 1 = no compression. Most TIFF writers and TIFF readers support only some TIFF compression schemes. Here are some examples of used TIFF compression schemes:

Related formats

BigTIFF

The TIFF file formats use 32-bit offsets, which limits file size to around 4

GiB The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

. Some implementations even use a signed 32-bit offset, running into issues around 2 GiB. BigTIFF is a TIFF variant file format which uses 64-bit offsets and supports much larger files (up to 18 exabytes in size). The BigTIFF file format specification was implemented in 2007 in development releases of

LibTIFF LibTIFF is a Library (computing), library for reading and writing Tagged Image File Format (abbreviated TIFF) files. The set also contains command line tools for processing TIFFs. It is distributed in source code and can be found as executable, bi ...

version 4.0, which was finally released as stable in December 2011. Support for BigTIFF file formats by applications is limited.

Exif

The

Exif Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other system ...

specification builds upon TIFF. For uncompressed image data, an Exif file is straight off a TIFF file with some private tags. For

compressed image data, Exif uses the

JPEG File Interchange Format The JPEG File Interchange Format (JFIF) is an image file format standard published as ITU-T Recommendation T.871 and ISO/IEC 10918-5. It defines supplementary specifications for the container format that contains the image data encoded with the JP ...

but embeds a TIFF file in the APP1 segment of the file. The first IFD (termed 0th in the Exif specification) of that embedded TIFF does not contain image data, and only houses metadata for the primary image. There may however be a

thumbnail Thumbnails are reduced-size versions of pictures or videos, used to help in recognizing and organizing them, serving the same role for images as a normal text index does for words. In the age of digital images, visual search engines and image ...

image in that embedded TIFF, which is provided by the second IFD (termed 1st in the Exif specification). The Exif audio file format does not build upon TIFF. Exif defines a large number of private tags for image metadata, particularly camera settings and

geopositioning Geopositioning, also known as geotracking, geolocalization, geolocating, geolocation, or geoposition fixing, is the process of determining or estimating the geographic position of an object. Geopositioning yields a set of geographic coordinates ...

data, but most of those do not appear in the ordinary TIFF IFDs. Instead these reside in separate IFDs which are pointed at by private tags in the main IFD.

TIFF/IT

TIFF/IT is used to send data for print-ready pages that have been designed on high-end prepress systems. The TIFF/IT specification (ISO 12639) describes a multiple-file format, which can describe a single page per file set. TIFF/IT files are not interchangeable with common TIFF files. The goals in developing TIFF/IT were to carry forward the original

IT8 IT8 is a set of American National Standards Institute (ANSI) standards for color communications and control specifications. Formerly governed by the IT8 Committee, IT8 activities were merged with those of the Committee for Graphics Arts Technolog ...

magnetic-tape formats into a medium-independent version. TIFF/IT is based on Adobe TIFF 6.0 specification and both extends TIFF 6, by adding additional tags, and restricts, it by limiting some tags and the values within tags. Not all valid TIFF/IT images are valid TIFF 6.0 images. TIFF/IT defines image-file formats for encoding color continuous-tone picture images, color

line art Line art or line drawing is any image that consists of distinct straight lines or curves placed against a background (usually plain), without gradations in shade (darkness) or hue (color) to represent two-dimensional or three-dimensional object ...

images, high-resolution continuous-tone images, monochrome continuous-tone images, binary picture images, binary line-art images, screened data, and images of composite final pages. There is no MIME type defined for TIFF/IT. The MIME type ''image/tiff'' should not be used for TIFF/IT files, because TIFF/IT does not conform to Baseline TIFF 6.0 and the widely deployed TIFF 6.0 readers cannot read TIFF/IT. The MIME type ''image/tiff'' (defined in RFC 3302) without an application parameter is used for Baseline TIFF 6.0 files or to indicate that it is not necessary to identify a specific subset of TIFF or TIFF extensions. The application parameter should be used with ''image/tiff'' to distinguish TIFF extensions or TIFF subsets. According to RFC 3302, specific TIFF subsets or TIFF extensions must be published as an RFC. There is no such RFC for TIFF/IT. There is also no plan by the ISO committee that oversees TIFF/IT standard to register TIFF/IT with either a parameter to image/tiff or as new separate MIME type.

TIFF/IT files

TIFF/IT consists of a number of different files and it cannot be created or opened by common desktop applications. TIFF/IT-P1 file sets usually consist of the following files: * Final Page (FP) * Continuous Tone image (CT) * Line Work image (LW) * High resolution Continuous-tone files (HC - optional) TIFF/IT also defines the following files: * Monochrome continuous-tone Picture images (MP) * Binary Picture images (BP) * Binary Line-art images (BL) * Screened Data (SD) Some of these data types are partly compatible with the corresponding definitions in the TIFF 6.0 specification. The Final Page (FP) allows the various files needed to define a complete page to be grouped together: it provides a mechanism for creating a package that includes separate image layers (of types CT, LW, etc.) to be combined to create the final printed image. Its use is recommended but not required. There must be at least one subfile in an FP file, but no more than one of each type. It typically contains a CT subfile and an LW subfile. The primary color space for this standard is CMYK, but also other color spaces and the use of ICC Profiles are supported.

TIFF/IT compression

TIFF/IT makes no provision for compression within the file structure itself, but there are no restrictions. (For example, it is allowed to compress the whole file structure in a ZIP archive.) LW files use a specific compression scheme known as Run-length encoding for LW (Compression tag value is 8080₁₆). HC files also use a specific Run-length encoding for HC (Compression tag value is 8081₁₆). The TIFF/IT P1 specs do not allow use of compression within the CT file. The following is a list of defined TIFF/IT compression schemes:

TIFF/IT P1

The ISO 12639:1998 introduced TIFF/IT-P1 (Profile 1) - a direct subset of the full TIFF/IT standard (previously defined in ANSI IT8.8–1993). This subset was developed on the ground of the mutual realization by both the standards and the software development communities that an implementation of the full TIFF/IT standard by any one vendor was both unlikely (because of its complexity), and unnecessary (because Profile 1 would cover most applications for digital ad delivery). Almost all TIFF/IT files in digital advertising were distributed as TIFF/IT-P1 file sets in 2001. When people talk about TIFF/IT, they usually mean the P1 standard. Here are some of the restrictions on TIFF/IT-P1 (compared to TIFF/IT): * Uses CMYK only (when appropriate) * It is pixel interleaved (when appropriate) * Has a single choice of image orientation * Has a single choice of dot range * Restricted compression methods TIFF/IT-P1 is a simplified conformance level of TIFF/IT and it maximizes the compatibility between Color Electronic Prepress Systems (CEPS) and Desk Top Publishing (DTP) worlds. It provides a clean interface for the proprietary CEPS formats such as the

Scitex CT Scitex Continuous Tone or Scitex CT is an image file format. It is designed specifically for use on Scitex graphics processing equipment. Its use is supported by numerous graphics suites and desktop publishing packages, such as Adobe Photoshop, A ...

/LW format.

TIFF/IT P2

Because TIFF/IT P1 had a number of limitations, an extended format was developed. The ISO 12639:2004 introduced a new extended conformance level - TIFF/IT-P2 (Profile 2). TIFF/IT-P2 added a number of functions to TIFF/IT-P1 like: * CMYK spot colors only (when appropriate) * Support for the compression of CT and BP data (JPEG and Deflate) * Support for multiple LW and CT files in a single file * Support for copydot files through a new file type called SD (Screened Data) * There was some effort to create a possibility to concatenate FP, LW, and CT files into a single file called the GF (Group Final) file, but this was not defined in a draft version of ISO 12639:2004. This format was not widely used.

Private tags

The TIFF/IT specification preserved the TIFF possibility for developers to utilize private tags. The TIFF/IT specification is very precise regarding how these private tags should be treated - they should be parsed, but ignored. Private tags in the TIFF/IT-P1 specification were originally intended to provide developers with ways to add specific functionality for specific applications. Private tags can be used by developers (e.g., Scitex) to preserve specific printing values or other functionality. Private tags are typically labelled with tag numbers greater than or equal to 32768. All private tags must be requested from Adobe (the TIFF administrator) and registered. In 1992, the DDAP (Digital Distribution of Advertising for Publication, later Digital Directions in Applications for Production) developed their requirement statement for digital ad delivery. This was presented to ANSI-accredited CGATS (Committee for Graphic Arts Technology Standards) for development of an accredited file format standard for the delivery of digital ads. CGATS reviewed their alternatives for this purpose and TIFF seemed like the ideal candidate, except for the fact that it could not handle certain required functionalities. CGATS asked Aldus (the TIFF administrator) for a block of their own TIFF private tags in order to implement what eventually became TIFF/IT. For example, the ability to identify the sequence of the colors is handled by tag 34017 - the Color Sequence Tag. TIFF/IT was created to satisfy the need for a transport-independent method of encoding raster data in the IT8.1, IT8.2 and IT8.5 standards.

Standards

TIFF/IT was defined in ANSI IT8.8–1993 standard in 1993 and later revised in the International Standard ''ISO 12639:1998 - Prepress digital data exchange – Tag image file format for image technology (TIFF/IT)''. The ISO standard replaces ANSI IT8.8–1993. It specifies a media-independent means for prepress electronic data exchange. The ISO 12639:2004 (Second edition) standard for TIFF/IT superseded the ISO 12639:1998. It was also later extended in ISO 12639:2004 / Amd. 1:2007 - Use of JBIG2-Amd2 compression in TIFF/IT.

References

External links

Adobe TIFF Resources page
Adobe links to the specification and main TIFF resources
LibTIFF Home Page
Widely used library used for reading and writing TIFF files as well as TIFF file processing command line tools

Everything you always wanted to know about the TIFF File Format but were afraid to ask
TIFF description
at Digital Preservation (The Library of Congress)

Specification for revision 4.0, in HTML (warning: for historical purposes only, the TIFF 6.0 spec contains the full 4.0 revision)

Specification for revision 5.0, in HTML (warning: for historical purposes only, the TIFF 6.0 spec contains the full 5.0 revision)
TIFF Revision 6.0
Specification for revision 6.0, in PDF (warning: there is an outdated and flawed section (jpeg compression), corrected in supplements, and there are additions to this PDF too – for the full specification, see th

* - image/tiff, and - image/tiff-fx, - Tag Image File Format (TIFF) - F Profile for Facsimile, - legacy exchange of images in the Internet.
Code Tiff Tag Reader
- Easy readable code of a TIFF tag reader in Mathworks Matlab (Tiff 5.0/6.0)
AlternaTIFF
- Free in-browser TIFF viewer * eiStream Annotation (also known as Wang or Kodak Annotation). Developed by eiStream. ** * ADEO Imaging Annotation ** {{Graphics file formats High dynamic range file formats Raster graphics file formats Adobe Inc.

History

Overview

Internet Media Type

Digital preservation

Details

Part 1: Baseline TIFF

Multiple subfiles

Strips

Compression

Image types

Byte order

Other TIFF fields

Part 2: TIFF Extensions

Compression

Image types

Image trees

=Tiles

Other extensions

Private tags

TIFF Compression Tag

Related formats

BigTIFF

Exif

TIFF/IT

TIFF/IT files

TIFF/IT compression

TIFF/IT P1

TIFF/IT P2

Private tags

Standards

See also

References

External links