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134-532: 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 formats . In the beginning, TIFF was only a binary image 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 images, then color images. Today, TIFF, along with JPEG and PNG ,

268-441: A color transparency mounted in the drum, with a light source placed underneath the film, and three photocells with red, green, and blue color filters reading each spot on the transparency to translate the image into three electronic signals. In Murray and Morse's initial design, the drum was connected to three lathes that etched cyan, magenta, and yellow (CMY) halftone dots onto three offset cylinders directly. The rights to

402-488: A computer which controls the scanner and stores scans. Small portable scanners, either sheetfed or handheld and operated by batteries and with storage capability, are available for use away from a computer; stored scans can be transferred later. Many can scan both small documents such as business cards and till receipts , as well as letter-sized documents. The higher-resolution cameras fitted to some smartphones can produce reasonable quality document scans by taking

536-429: A contact image sensor (CIS) as the image sensor, whereas drum scanners , developed earlier and still used for the highest possible image quality, use a photomultiplier tube (PMT) as the image sensor. Document cameras , which use commodity or specialized high-resolution cameras, photograph documents all at once. Image scanners are considered the successors of early facsimile (fax) machines. The earliest attempt at

670-667: A d -dimensional N 1 × N 2 × ⋯ × N d {\displaystyle N_{1}\times N_{2}\times \cdots \times N_{d}} array with dimensions N k ( k =1... d ), a given element of this array is specified by a tuple ( n 1 , n 2 , … , n d ) {\displaystyle (n_{1},n_{2},\ldots ,n_{d})} of d (zero-based) indices n k ∈ [ 0 , N k − 1 ] {\displaystyle n_{k}\in [0,N_{k}-1]} . In row-major order,

804-483: A lossless 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 and pages. TIFF offers the option of using LZW compression, a lossless data-compression technique for reducing

938-469: A lossless compression scheme, or compressed using a lossy compression 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

1072-432: 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 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.) Image scanner An image scanner (often abbreviated to just scanner )

1206-429: A Dmax close to 4.0d with proper exposure, and so can black-and-white negative film. Consumer-level flatbed photo scanners have a dynamic range in the 2.0–3.0 range, which can be inadequate for scanning all types of photographic film , as Dmax can be and often is between 3.0d and 4.0d with traditional black-and-white film. Color film compresses its 12 stops of a possible 16 stops (film latitude) into just 2.0d of space via

1340-568: A computer could read and store into memory. The computer of choice at the time was the SEAC mainframe ; the maximum horizontal resolution that the SEAC was capable of processing was 176 pixels. The first image ever scanned on this machine was a photograph of Kirsch's three-month-old son, Walden. In 1969, Dacom introduced the 111 fax machine, which was the first digital fax machine to employ data compression using an on-board computer. It employed

1474-496: 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: A baseline TIFF file can contain

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1608-419: A document in order to judge what area of the document should be scanned (if not the entirety of it), before scanning it at a higher resolution. Some flatbed scanners incorporate sheet-feeding mechanisms called automatic document feeders (ADFs) that use the same scanning element as the flatbed portion. This type of scanner is sometimes called a reflective scanner , because it works by shining white light onto

1742-533: A fax machine was patented in 1843 by the Scottish clockmaker Alexander Bain but never put into production. In his design, a metal stylus linked to a pendulum scans across a copper plate with a raised image. When the stylus makes contact with a raised part of the plate, it sends a pulse across a pair of wires to a receiver containing an electrode linked to another pendulum. A piece of paper impregnated with an electrochemically sensitive solution resides underneath

1876-455: 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: 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

2010-485: A flatbed design with a continuous feed capable of scanning up to letter paper in 1-bit monochrome (black and white). The first flatbed scanner used for digital image processing was the Autokon 8400, introduced by ECRM Inc., a subsidiary of AM International , in 1975. The Autokon 8400 used a laser beam to scan pages up to 11 by 14 inches at a maximum resolution of 1000 lines per inch. Although it

2144-669: A laser onto the page for calibration and software skew correction. A film scanner , also known as a slide scanner or a transparency scanner, is a type of specialized flatbed scanner specifically for scanning film negatives and slides . A typical film scanner works by passing a narrowly focused beam of light through the film and reading the intensity and color of the light that emerges. The lowest-cost dedicated film scanners can be had for less than $ 50, and they might be sufficient for modest needs. From there they inch up in staggered levels of quality and advanced features upward of five figures. Image scanners are usually used in conjunction with

2278-423: A mainstream commodity". A flatbed scanner is a type of scanner that provides a glass bed ( platen ) on which the object to be scanned lies motionless. The scanning element moves vertically from under the glass, scanning either the entirety of the platen or a predetermined portion. The driver software for most flatbed scanners allows users to prescan their documents—in essence, to take a quick, low-resolution pass at

2412-434: A metallic drum and stylus. It was even more commercially successful than Gray's machine and became the basis for telephotography machines used by newspapers around the world from the early 1900s onward. Alexander Murray and Richard Morse invented and patented the first analog color scanner at Eastman Kodak in 1937. Intended for color separation at printing presses , their machine was an analog drum scanner that imaged

2546-511: A native row-major or column-major storage order for these arrays. Row-major order is used in C / C++ / Objective-C (for C-style arrays), PL/I , Pascal , Speakeasy , and SAS . Column-major order is used in Fortran , IDL , MATLAB , GNU Octave , Julia , S , S-PLUS , R , Scilab , Yorick , and Rasdaman . A typical alternative for dense array storage is to use Iliffe vectors , which typically store pointers to elements in

2680-405: A normal letter and much longer, remain available as of 2024 . Some computer mice can also scan documents. A drum scanner is a type of scanner that uses a clear, motor-driven rotating cylinder (drum) onto which a print, a film negative, a transparency, or any other flat object is taped or otherwise secured. A beam of light either projects past, or reflects off, the material to be scanned onto

2814-576: 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. 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

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2948-412: A photograph with the phone's camera and post-processing it with a scanning app, a range of which are available for most phone operating systems , to whiten the background of a page, correct perspective distortion so that the shape of a rectangular document is corrected, convert to black-and-white, etc. Many such apps can scan multiple-page documents with successive camera exposures and output them either as

3082-439: 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 floats, as well as specify a custom range for valid sample values. TIFF images may be uncompressed, compressed using

3216-403: A pulse; the result is a reverse contrast (white-on-blue) reproduction of the original image. Bakewell's fax machine was marginally more successful than Bain's but suffered from the same synchronization issues. In 1862, Giovanni Caselli solved this with the pantelegraph , the first fax machine put into regular service. Largely based on Bain's design, it ensured complete synchronization by flanking

3350-710: 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

3484-511: A scan of a letter-sized print at 200-dpi; its grayscale counterpart, the DS-200, took only 30 seconds to make a scan at the same size and resolution. The first relatively affordable flatbed scanner for personal computers appeared in February 1987 with Hewlett-Packard 's ScanJet , which was capable of scanning 4-bit (64-shade) grayscale images at a maximum resolution of 300 dpi. By

3618-513: A scanner is its resolution , measured in pixels per inch (ppi), sometimes more accurately referred to as samples per inch (spi). Instead of using the scanner's true optical resolution, the only meaningful parameter, manufacturers like to refer to the interpolated resolution, which is much higher thanks to software interpolation . As of 2009 , a high-end flatbed scanner can scan up to 5400 ppi and drum scanners have an optical resolution of between 3000 and 24000 ppi. Effective resolution refers to

3752-403: A scanner with at least a 3.6d dynamic range, but also a Dmax between 4.0d to 5.0d. High-end (photo lab) flatbed scanners can reach a dynamic range of 3.7, and Dmax around 4.0d. Dedicated film scanners have a dynamic range between 3.0d–4.0d. Office document scanners can have a dynamic range of less than 2.0d. Drum scanners have a dynamic range of 3.6–4.5. For scanning film, infrared cleaning

3886-561: 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. This allows the images to be defined along a tree structure . 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. A TIFF image may also be composed of

4020-418: A series of mirrors, which focus the beam onto the drum scanner's photomultiplier tube (PMT). After one revolution, the beam of light moves down a single step. When scanning transparent media, such as negatives, a light beam is directed from within the cylinder onto the media; when scanning opaque items, a light beam from above is reflected off the surface of the media. When only one PMT is present, three passes of

4154-552: 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 version 4.0, which was finally released as stable in December 2011. Support for BigTIFF file formats by applications is limited. The Exif specification builds upon TIFF. For uncompressed image data, an Exif file

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4288-612: A single apparatus that can be made available to all members of a workgroup. Battery-powered portable scanners store scans on internal memory; they can later be transferred to a computer either by direct connection, typically USB, or in some cases a memory card may be removed from the scanner and plugged into the computer. A raster image editor must be able to communicate with a scanner. There are many different scanners, and many of those scanners use different protocols. In order to simplify applications programming, some application programming interfaces (APIs) were developed. The API presents

4422-444: A single file or multiple-page files. Some smartphone scanning apps can save documents directly to online storage locations, such as Dropbox and Evernote , send via email, or fax documents via email-to-fax gateways. Smartphone scanner apps can be broadly divided into three categories: Scanners equipped with charge-coupled device (CCD) scanning elements require a sophisticated series of mirrors and lenses to reproduce an image, but

4556-449: A single frame of the output as an image file. Document cameras may even use the same APIs as scanners when connected to computers. A planetary scanner is a type of very-high-resolution document camera used for capturing certain fragile documents. A book scanner is another kind of document camera, pairing a digital camera with a scanning area defined by a mat to assist in scanning books. Some more advanced models of book scanners project

4690-577: A stride value, and row-major or column-major are just two possible resulting interpretations. Row-major order is the default in NumPy (for Python). Column-major order is the default in Eigen and Armadillo (both for C++). A special case would be OpenGL (and OpenGL ES ) for graphics processing. Since "recent mathematical treatments of linear algebra and related fields invariably treat vectors as columns," designer Mark Segal decided to substitute this for

4824-685: 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. The MIME type image/tiff (defined in RFC 3302) without an application parameter

4958-512: 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

5092-422: A time or multiple, as in an automatic document feeder . A handheld scanner is a portable version of an image scanner that can be used on any flat surface. Scans are usually downloaded to the computer that the scanner is connected to, although some scanners are able to store scans on standalone flash media (e.g., memory cards and USB drives ). Modern scanners typically use a charge-coupled device (CCD) or

5226-470: A time past a stationary scanning element (two scanning elements, in the case of scanners with duplex functionality). Unlike flatbed scanners, sheetfed scanners are not equipped to scan bound material such as books or magazines, nor are they suitable for any material thicker than plain printer paper. Some sheetfed scanners, called automatic document feeders (ADFs), are capable of scanning several sheets in one session, although others only accept one page at

5360-451: A time. Some sheetfed scanners are portable , powered by batteries, and have their own storage, eventually transferring stored scans to a computer. A handheld scanner is a type of scanner that must be manually dragged or gilded by hand across the surface of the object to be scanned. Scanning documents in this manner requires a steady hand, as an uneven scanning rate produces distorted images. Some handheld scanners have an indicator light on

5494-401: A two- byte indicator of byte order : " II " for little-endian (a.k.a. "Intel byte ordering", c.  1980 ) or " MM " for big-endian (a.k.a. "Motorola byte ordering", c.  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

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5628-584: A uniform interface to the scanner. This means that the application does not need to know the specific details of the scanner in order to access it directly. For example, Adobe Photoshop supports the TWAIN standard; therefore in theory Photoshop can acquire an image from any scanner that has a TWAIN driver. Row- and column-major order 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

5762-405: 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 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. TIFF

5896-430: Is orders of magnitude faster than nonsequential access. The terms row-major and column-major stem from the terminology related to ordering objects. A general way to order objects with many attributes is to first group and order them by one attribute, and then, within each such group, group and order them by another attribute, etc. If more than one attribute participates in ordering, the first would be called major and

6030-400: Is a device that optically scans images, printed text, handwriting , or an object and converts it to a digital image . The most common type of scanner used in offices and in the home is the flatbed scanner , where the document is placed on a glass window for scanning. A sheetfed scanner , which moves the page across an image sensor using a series of rollers, may be used to scan one document at

6164-466: 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 ) defining the image's geometry. A TIFF file, for example, can be a container holding JPEG (lossy) and PackBits (lossless) compressed images. A TIFF file also can include a vector -based clipping path (outlines, croppings, image frames). The ability to store image data in

6298-512: Is a popular format for deep-color images. The first version of the TIFF specification was published by the Aldus Corporation 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

6432-412: Is a technique used to remove the effects of dust and scratches on images scanned from film; many modern scanners incorporate this feature. It works by scanning the film with infrared light; the dyes in typical color film emulsions are transparent to infrared light, but dust and scratches are not, and block infrared; scanner software can use the visible and infrared information to detect scratches and process

6566-549: Is a type of scanner that places the scanning element in a housing on top of a vertical post, hovering above the document or object to be scanned, which lies stationary on an open-air bed. Chinon Industries patented a specific type of overhead scanner, which uses a rotating mirror to reflect the contents of the bed onto a linear CCD, in 1987. Although very flexible—allowing users to scan not only two-dimensional prints and documents but any 3D object, of any size—the Chinon design required

6700-511: 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 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

6834-521: Is critical for correctly passing arrays between programs written in different programming languages. It is also important for performance when traversing an array because modern CPUs process sequential data more efficiently than nonsequential data. This is primarily due to CPU caching which exploits spatial locality of reference . In addition, contiguous access makes it possible to use SIMD instructions that operate on vectors of data. In some media such as magnetic-tape data storage , accessing sequentially

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6968-400: Is given by the multiplication value in parentheses before index n k in the right-hand side summations above. More generally, there are d! possible orders for a given array, one for each permutation of dimensions (with row-major and column-order just 2 special cases), although the lists of stride values are not necessarily permutations of each other, e.g., in the 2-by-3 example above,

7102-420: Is in its first row and second column. This convention is carried over to the syntax in programming languages, although often with indexes starting at 0 instead of 1. Even though the row is indicated by the first index and the column by the second index, no grouping order between the dimensions is implied by this. The choice of how to group and order the indices, either by row-major or column-major methods,

7236-694: 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. The TIFF Tag 259 (0103 16 ) 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: The TIFF file formats use 32-bit offsets , which limits file size to around 4 GiB . Some implementations even use

7370-415: Is made up of one or several samples ; for example an RGB 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 (e.g. RGB, RGBA ) and subtractive (e.g. CMYK ) color models. TIFF does not constrain the number of samples per pixel (except that there must be enough samples for

7504-639: 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

7638-514: 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 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: TIFF/IT also defines the following files: Some of these data types are partly compatible with

7772-505: 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 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

7906-541: Is straight off a TIFF file with some private tags. For JPEG compressed image data, Exif uses the JPEG File Interchange Format 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 image in that embedded TIFF, which

8040-488: Is the space taken up in the 0 to 5 scale, and Dmin and Dmax denote where the least dense and most dense measurements on a negative or positive film. The density range of negative film is up to 3.6d, while slide film dynamic range is 2.4d. Color negative density range after processing is 2.0d thanks to the compression of the 12 stops into a small density range. Dmax will be the densest on slide film for shadows, and densest on negative film for highlights. Some slide films can have

8174-466: Is thus a matter of convention. The same terminology can be applied to even higher dimensional arrays. Row-major grouping starts from the leftmost index and column-major from the rightmost index, leading to lexicographic and colexicographic (or colex) orders , respectively. For example, the array could be stored in two possible ways: Programming languages handle this in different ways. In C , multidimensional arrays are stored in row-major order, and

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8308-406: Is to assign non-conventional roles to the indexes (using the first index for the column and the second index for the row), and another is to bypass language syntax by explicitly computing positions in a one-dimensional array. Of course, deviating from convention probably incurs a cost that increases with the degree of necessary interaction with conventional language features and other code, not only in

8442-402: Is to encode a multipage telefax 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

8576-591: Is typically an expensive operation, some systems provide options to specify individual matrices as being stored transposed. The programmer must then decide whether or not to rearrange the elements in memory, based on the actual usage (including the number of times that the array is reused in a computation). For example, the Basic Linear Algebra Subprograms functions are passed flags indicating which arrays are transposed. The concept generalizes to arrays with more than two dimensions. For

8710-425: 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

8844-417: 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 magnetic-tape formats into a medium-independent version. TIFF/IT

8978-467: The A[i] row part can even be assigned to an intermediate variable that is then indexed in a separate expression. (No other implications should be assumed, e.g., Fortran is not column-major simply because of its notation, and even the above implication could intentionally be circumvented in a new language.) To use column-major order in a row-major environment, or vice versa, for whatever reason, one workaround

9112-401: The empty product is the multiplicative identity element , i.e., ∏ ℓ = 1 0 N ℓ = ∏ ℓ = d + 1 d N ℓ = 1 {\textstyle \prod _{\ell =1}^{0}N_{\ell }=\prod _{\ell =d+1}^{d}N_{\ell }=1} . For a given order, the stride in dimension k

9246-745: The first dimension is contiguous, so that the memory-offset of this element is given by: n 1 + N 1 ⋅ ( n 2 + N 2 ⋅ ( n 3 + N 3 ⋅ ( ⋯ + N d − 1 n d ) ⋯ ) ) = ∑ k = 1 d ( ∏ ℓ = 1 k − 1 N ℓ ) n k {\displaystyle n_{1}+N_{1}\cdot (n_{2}+N_{2}\cdot (n_{3}+N_{3}\cdot (\cdots +N_{d-1}n_{d})\cdots ))=\sum _{k=1}^{d}\left(\prod _{\ell =1}^{k-1}N_{\ell }\right)n_{k}} where

9380-815: The last dimension is contiguous, so that the memory-offset of this element is given by: n d + N d ⋅ ( n d − 1 + N d − 1 ⋅ ( n d − 2 + N d − 2 ⋅ ( ⋯ + N 2 n 1 ) ⋯ ) ) = ∑ k = 1 d ( ∏ ℓ = k + 1 d N ℓ ) n k {\displaystyle n_{d}+N_{d}\cdot (n_{d-1}+N_{d-1}\cdot (n_{d-2}+N_{d-2}\cdot (\cdots +N_{2}n_{1})\cdots ))=\sum _{k=1}^{d}\left(\prod _{\ell =k+1}^{d}N_{\ell }\right)n_{k}} In column-major order,

9514-484: The Autokon 8500, capable of scanning up to 1200 lines per inch. Four of ECRM's competitors introduced commercial flatbed scanners that year, including Scitex , Agfa-Gevaert , and Linotype-Hell , all of which were capable of scanning larger prints at higher resolutions. In 1977, Raymond Kurzweil , of his start-up company Kurzweil Computer Products, released the Kurzweil Reading Machine, which

9648-590: The C-based API because individual elements would be accessed as M[vector][coordinate] or, effectively, M[column][row] , which unfortunately muddled the convention that the designer sought to adopt, and this was even preserved in the OpenGL Shading Language that was later added (although this also makes it possible to access coordinates by name instead, e.g., M[vector].y ). As a result, many developers will now simply declare that having

9782-640: The IS-22, a cartridge that fit into their inkjet printers to convert them into sheetfed scanners. In early 1985, the first flatbed scanner for the IBM PC , the Datacopy Model 700, was released. Based on a CCD imaging element, the Model 700 was capable of scanning letter-sized documents at a maximum resolution of 200 dpi at 1-bit monochrome. The Model 700 came with a special interface card for connecting to

9916-561: The Macintosh simultaneously. The ImageWriter's carriage, controlled by the ThunderScan, moves left-to-right to scan one 200- dpi (dots per inch) line at a time, with the carriage return serving to advance the scanner down the print to be scanned. The ThunderScan was the Macintosh's first scanner and sold well but operated very slowly and was only capable of scanning prints at 1-bit monochrome. In 1999, Canon iterated on this idea with

10050-684: The PC, and an optional, aftermarket OCR software card and software package were sold for the Model 700. In April 1985, LaserFAX Inc. introduced the first CCD-based color flatbed scanner, the SpectraSCAN 200, for the IBM PC. The SpectraSCAN 200 worked by placing color filters over the CCD and taking four passes (three for each primary color and one for black) per scan to build up a color reproduction. The SpectraSCAN 200 took between two and three minutes to produce

10184-512: 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. 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. Many TIFF readers support tags additional to those in Baseline TIFF, but not every reader supports every extension. As

10318-519: 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 which were published in September 1995 and March 2002 respectively. A TIFF file contains one or several images, termed subfiles in the specification. The basic use case for having multiple subfiles

10452-410: 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

10586-508: The application parameter must be published as an RFC. MIME 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 compatible with the ITU-T Recommendations for Group 3 black-and-white, grayscale and color fax . Adobe holds the copyright on the TIFF specification (aka TIFF 6.0) along with

10720-554: The array indexes are written  row-first (lexicographical access order): On the other hand, in Fortran , arrays are stored in column-major order, while the array indexes are still written row-first (colexicographical access order): Note how the use of A[i][j] with multi-step indexing as in C, as opposed to a neutral notation like A(i,j) as in Fortran, almost inevitably implies row-major order for syntactic reasons, so to speak, because it can be rewritten as (A[i])[j] , and

10854-468: The array. This data is then processed with some proprietary algorithm to correct for different exposure conditions, and sent to the computer via the device's input/output interface (usually USB, previous to which was SCSI or bidirectional parallel port in older units). Color depth varies depending on the scanning array characteristics, but is usually at least 24 bits. High-quality models have 36-48 bits of color depth. Another qualifying parameter for

10988-445: The beam of light focused on a given spot on the plate gets reflected and bounced off to a photocell adjacent to the projector. Each photocell connects to an analog image processor , which evaluates the reflectance of the combined CMY values using Neugebauer equations and outputs a signal to a light projector hovering over a fourth, unexposed lithographic plate. This plate receives a color-corrected, continuous-tone dot-etch of either

11122-575: The beginning of 1988, the ScanJet had accounted for 27 percent of all scanner sales in terms of dollar volume, per Gartner Dataquest . In February 1989, the company introduced the ScanJet Plus, which increased the bit depth to 8 bits (256 shades) while costing only US$ 200 more than the original ScanJet's $ 1990 (equivalent to $ 4,891 in 2023). This led to a massive price drop in grayscale scanners with equivalent or lesser features in

11256-523: The best possible quality is required lossless compression should be used; reduced-quality files of smaller size can be produced from such an image when required (e.g., image designed to be printed on a full page, and a much smaller file to be displayed as part of a fast-loading web page). Purity can be diminished by scanner noise, optical flare, poor analog to digital conversion, scratches, dust, Newton's rings , out-of-focus sensors, improper scanner operation, and poor software. Drum scanners are said to produce

11390-644: 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 order, left to right and top to bottom. The data for one pixel

11524-454: 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 , and hyperspectral imaging may require hundreds of samples per pixel. TIFF supports having all samples for

11658-458: The column as the first index is the definition of column-major, even though this is clearly not the case with a real column-major language like Fortran. Torch (for Lua) changed from column-major to row-major default order. As exchanging the indices of an array is the essence of array transposition , an array stored as row-major but read as column-major (or vice versa) will appear transposed. As actually performing this rearrangement in memory

11792-533: The complex optics of CCDs scanners. However, their depth of field is much worse, resulting in blurry scans if the scanned document is not perfectly flush against the platten. Because the sensors require far less power than CCD scanners, CIS scanners are able to be manufactured down to a low cost and are typically much lighter in weight and depth than CCD scanners. Scanners equipped with photomultiplier tubes (PMT) are nearly exclusively drum scanners . Color scanners typically read RGB (red-green-blue) color data from

11926-651: The content and document management industry associated with the use of TIFF files arise when the structures contain proprietary headers, are not properly documented, or contain "wrappers" or other containers around the TIFF datasets, or include improper compression technologies, or those compression technologies are not properly implemented. Variants of TIFF can be used within document imaging and content/document management systems using CCITT Group IV 2D compression which supports black-and-white (bitonal, monochrome ) images, among other compression technologies that support color . When storage capacity and network bandwidth

12060-556: The convention in predecessor IRIS GL , which was to write vectors as rows; for compatibility, transformation matrices would still be stored in vector-major (=row-major) rather than coordinate-major (=column-major) order, and he then used the trick "[to] say that matrices in OpenGL are stored in column-major order". This was really only relevant for presentation, because matrix multiplication was stack-based and could still be interpreted as post-multiplication, but, worse, reality leaked through

12194-467: 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

12328-507: The cyan, magenta, or yellow values. The fourth plate is replaced with another unexposed plate, and the process repeats until three color-corrected plates, of cyan, magenta and yellow, are produced. In the 1950s, the Radio Corporation of America (RCA) took Hardy and Wurzburg's patent and replaced the projector-and-photocell arrangement with a video camera tube focusing on one spot of the plate. The first digital imaging system

12462-450: 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. 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

12596-440: The early 1990s professional flatbed scanners were available over a local computer network . This proved useful to publishers, print shops, etc. This functionality largely fell out of use as the cost of flatbed scanners reduced enough to make sharing unnecessary. From 2000 all-in-one multi-purpose devices became available which were suitable for both small offices and consumers, with printing, scanning, copying, and fax capability in

12730-500: The electrode and changes color whenever a pulse reaches the electrode. A gear advances the copper plate and paper in tandem with each swing of the pendulum; over time, the result is a perfect reproduction of the copper plate. In Bain's system, it is critical that the pendulums of the transceiver and receiver are in perfect step, or else the reproduced image will be distorted. In 1847, the English physicist Frederick Bakewell developed

12864-460: 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. Baseline TIFF readers must handle the following three compression schemes: Baseline TIFF image types are: bilevel, grayscale, palette-color, and RGB full-color images. Every TIFF file begins with

12998-467: 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. 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

13132-475: 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

13266-421: The first working fax machine. Bakewell's machine was similar to Bain's but used a revolving drum coated in tinfoil, with non-conductive ink painted on the foil and a stylus that scans across the drum and sends a pulse down a pair of wires when it contacts a conductive point on the foil. The receiver contains an electrode that touches a sheet of chemically treated paper, which changes color when the electrode receives

13400-532: The form of increased vulnerability to mistakes (forgetting to also invert matrix multiplication order, reverting to convention during code maintenance, etc.), but also in the form of having to actively rearrange elements, all of which have to be weighed against any original purpose such as increasing performance. Running the loop row-wise is preferred in row-major languages like C and vice versa for column-major languages. Programming languages or their standard libraries that support multi-dimensional arrays typically have

13534-537: 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 . 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 need not be equal (since in

13668-672: The image are required for a full-color RGB scan. When three PMTs are present, only a single pass is required. The photomultiplier tubes of drum scanners offer superior dynamic range to that of CCD sensors. For this reason, drum scanners can extract more detail from very dark shadow areas of a transparency than flatbed scanners using CCD sensors. The smaller dynamic range of the CCD sensors (versus photomultiplier tubes) can lead to loss of shadow detail, especially when scanning very dense transparency film. Drum scanners are also able to resolve true detail in excess of 10000 dpi, producing higher-resolution scans than any CCD scanner. An overhead scanner

13802-781: The image to greatly reduce their visibility, considering their position, size, shape, and surroundings. Scanner manufacturers usually have their own names attached to this technique. For example, Epson , Minolta , Nikon , Konica Minolta , Microtek , and others use Digital ICE , while Canon uses its own system, FARE (Film Automatic Retouching and Enhancement). Plustek uses LaserSoft Imaging iSRD . Some independent software developers design infrared cleaning tools. By combining full-color imagery with 3D models, modern hand-held scanners are able to completely reproduce objects electronically. The addition of 3D color printers enables accurate miniaturization of these objects, with applications across many industries and professions. For scanner apps,

13936-494: The image was achieved with a lamp passing over the punched holes, exposing five different intensities of light onto a film negative. The first scanner to store its images digitally onto a computer was a drum scanner built in 1957 at the National Bureau of Standards (NBS, later NIST) by a team led by Russell A. Kirsch . It used a photomultiplier tube to detect light at a given point and produced an amplified signal that

14070-505: The image; later ones scan in monochrome or color, as desired. A hand scanner may also have a small window through which the document being scanned could be viewed. As hand scanners are much narrower than most normal document or book sizes, software (or the end user) needed to combine several narrow "strips" of scanned documents to produce the finished article. Inexpensive, portable , battery-powered or USB-powered wand scanners and pen scanners, typically capable of scanning an area as wide as

14204-451: The last minor . If two attributes participate in ordering, it is sufficient to name only the major attribute. In the case of arrays, the attributes are the indices along each dimension. For matrices in mathematical notation, the first index indicates the row , and the second indicates the column , e.g., given a matrix A {\displaystyle A} , the entry a 1 , 2 {\displaystyle a_{1,2}}

14338-442: The level of captured detail. The size of the file created increases with the square of the resolution; doubling the resolution quadruples the file size . A resolution must be chosen that is within the capabilities of the equipment, preserves sufficient detail, and does not produce a file of excessive size. The file size can be reduced for a given resolution by using "lossy" compression methods such as JPEG, at some cost in quality. If

14472-401: The market. The number of third-party developers producing software and hardware supporting these scanners jumped dramatically in turn, effectively popularizing the scanner for the personal computer user. By 1999, the cost of the average color-capable scanner had dropped to $ 300 (equivalent to $ 549 in 2023). That year, Computer Shopper declared 1999 "the year that scanners finally became

14606-521: The mid-1980s, starting with ThunderScan for the Macintosh in December 1984. Designed by Andy Hertzfeld and released by Thunderware Inc., the ThunderScan contains a specialized image sensor built into a plastic housing the same shape as the ink ribbon cartridge of Apple 's ImageWriter printer. The ThunderScan slots into the ImageWriter's ribbon carrier and connects to both the ImageWriter and

14740-474: The object to be scanned and reading the intensity and color of light that is reflected from it, usually a line at a time. They are designed for scanning prints or other flat, opaque materials, but some have available transparency adapters, which—for a number of reasons—in most cases, are not very well suited to scanning film. A sheetfed scanner, also known as a document feeder, is a type of scanner that uses motor-driven rollers to move one single sheet of paper at

14874-574: The offset cylinders. In 1948, Arthur Hardy of the Interchemical Corporation and F. L. Wurzburg of the Massachusetts Institute of Technology invented the first analog, color flatbed image scanner, intended for producing color-corrected lithographic plates from a color negative. In this system, three color-separated plates (of CMY values) are prepared from a color negative via dot etching and placed in

15008-404: The orders lies in which elements of an array are contiguous in memory. In row-major order, the consecutive elements of a row reside next to each other, whereas the same holds true for consecutive elements of a column in column-major order. While the terms allude to the rows and columns of a two-dimensional array, i.e. a matrix , the orders can be generalized to arrays of any dimension by noting that

15142-496: The patent were sold to Printing Developments Incorporated (P.D.I.) in 1946, who improved on the design by using a photomultiplier tube to image the points on the negative, which produced an amplified signal that was then fed to a single-purpose computer that processed the RGB signals into color-corrected cyan, magenta, yellow, and black (CMYK) values. The processed signals are then sent to four lathes that etch CMYK halftone dots onto

15276-485: The pendulums of both the transceiver and receiver between two magnetic regulators, which become magnetized with each swing of the pendulum and become demagnetized when the pendulum reaches the maxima and minima of each oscillation. In 1893, the American engineer Elisha Gray introduced the telautograph , the first widely commercially successful fax machine that used linkage bars translating x - and y -axis motion at

15410-422: The process of dye coupling and removal of all silver from the emulsion. Kodak Vision 3 has 18 stops. So, color-negative film scans the easiest of all film types on the widest range of scanners. Because traditional black-and-white film retains the image creating silver after processing, density range can be almost twice that of color film. This makes scanning traditional black-and-white film more difficult and requires

15544-469: The purest digital representations of the film, followed by high-end film scanners that use the larger Kodak Tri-Linear sensors. The third important parameter for a scanner is its dynamic range (also known as density range). A high-density range means that the scanner is able to record shadow details and brightness details in one scan. Density of film is measured on a base 10 log scale and varies between 0.0 (transparent) and 5.0, about 16 stops. Density range

15678-461: The receiver to scan a pen across the paper and strike it only when actuated by the stylus moving across the transceiver drum. Because it could use commodity stationery paper, it became popular in business and hospitals. In 1902, the German engineer Arthur Korn introduced the phototelautograph, a fax machine that used a light-sensitive selenium cell to scan a paper to be copied, instead of relying on

15812-423: The result of this complexity is a much higher-quality scan. Because CCDs have a much greater depth of field, they are more forgiving when it comes to scanning documents that are difficult to get perfectly flat against the platen (such as bound books). Scanners equipped with contact image sensor (CIS) scanning elements are designed to be in near-direct contact with the document to be scanned and thus do not require

15946-669: The same row contiguously (like row-major order), but not the rows themselves. They are used in (ordered by age): Java , C# / CLI / .Net , Scala , and Swift . Even less dense is to use lists of lists, e.g., in Python , and in the Wolfram Language of Wolfram Mathematica . An alternative approach uses tables of tables, e.g., in Lua . Support for multi-dimensional arrays may also be provided by external libraries, which may even support arbitrary orderings, where each dimension has

16080-422: The same starting position. The Bartlane system was initially used exclusively by telegraph, with the five-bit Baudot code used to transmit the grayscale digital image. In 1921, the system was modified for offline use, with a five-bit paper tape punch punching holes depending on whether its connections to the contacts are bridged or not. The result was a stored digital image with five gray levels. Reproduction of

16214-410: The scan quality is highly dependent on the quality of the phone camera and on the framing chosen by the user of the app. Scans must virtually always be transferred from the scanner to a computer or information storage system for further processing or storage. There are two basic issues: (1) how the scanner is physically connected to the computer and (2) how the application retrieves the information from

16348-408: The scanner bed. Above each plate are rigidly fixed, equidistant light beam projectors that focus a beam of light onto one corner of the plate. The entire bed with all three plates moves horizontally, back and forth, to reach the opposite corners of the plate; with each horiztonal oscillation of the bed, the bed moves down one step to cover the entire vertical area of the plate. While this is happening,

16482-482: The scanner for this purpose, actuating if the user is moving the scanner too fast. They typically have at least one button that starts the scan when pressed; it is held by the user for the duration of the scan. Some other handheld scanners have switches to set the optical resolution , as well as a roller, which generates a clock pulse for synchronization with the computer. Older hand scanners were monochrome , and produced light from an array of green LEDs to illuminate

16616-459: The scanner. The file size of a scan can go up to about 100 MB for a 600 dpi, 23 × 28 cm (slightly larger than A4 paper ) uncompressed 24-bit image. Scanned files must be transferred and stored. Scanners can generate this volume of data in a matter of seconds, making a fast connection desirable. Scanners communicate to their host computer using one of the following physical interfaces, listing roughly from slow to fast: During

16750-406: The terms row-major and column-major are equivalent to lexicographic and colexicographic orders , respectively. It is also worth noting that matrices, being commonly represented as collections of row or column vectors, using this approach are effectively stored as consecutive vectors or consecutive vector components. Such ways of storing data are referred to as AoS and SoA respectively. Data layout

16884-440: The true resolution of a scanner, and is determined by using a resolution test chart. The effective resolution of most all consumer flatbed scanners is considerably lower than the manufactures' given optical resolution. Manufacturers often claim interpolated resolutions as high as 19200 ppi; but such numbers carry little meaningful value because the number of possible interpolated pixels is unlimited, and doing so does not increase

17018-578: The two supplements that have been published. These documents can be found on the Adobe TIFF Resources page. The Fax 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

17152-466: The user to provide uniform illumination of the object to be scanned and was more cumbersome to set up. A more modern type of overhead scanner is a document camera (also known as a video scanner), which uses a digital camera to capture a document all at once. Most document cameras output live video of the document and are usually reserved for displaying documents to a live audience, but they may also be used as replacements for image scanners, capturing

17286-480: 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

17420-627: Was only capable of scanning in 1-bit monochrome, the on-board processor was capable of halftoning, unsharp masking , contrast adjustment, and anamorphic distortions , among other features. The Autokon 8400 could either be connected to a film recorder to create a negative for producing plates or connected to a mainframe or minicomputer for further image processing and digital storage. The Autokon 8400 enjoyed widespread use in newspapers—ECRM shipped 1,000 units to newspaper publishers by 1985 —but its limited resolution and maximum scan size made it unsuitable for commercial printing. In 1982, ECRM introduced

17554-404: Was released and it added support for palette color images and LZW compression . 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

17688-436: 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: 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

17822-530: Was the Bartlane system in 1920. Named after the pair who invented it, Harry G. Bartholomew and Maynard D. McFarlane, the Bartlane system used zinc plates etched with an image from a film negative projected at five different exposure levels to correspond to five quantization levels. All five plates are affixed to a long, motor-driven rotating cylinder, with five equidistant contacts scanning over each plate at

17956-450: Was the first flatbed scanner with a charge-coupled device (CCD) imaging element. The Kurzweil Reading Machine was invented to assist blind people in reading books that had not been translated to braille . It comprised the image scanner and a Data General Nova minicomputer —the latter performing the image processing, optical character recognition (OCR), and speech synthesis . The first scanners for personal computers appeared in

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