NationMaster - Encyclopedia: Bitmap

In computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to the similar concept of a spatially mapped array of pixels. Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or in memory. Suppose the smiley face in the top left corner is an RGB bitmap image. ... A bit array (or bitmap, in some cases) is an array data structure which compactly stores individual bits (boolean values). ... A filename extension is a suffix to the name of a computer file applied to show its format. ... Multipurpose Internet Mail Extensions (MIME) is an Internet Standard that extends the format of e-mail to support: text in character sets other than US-ASCII; non-text attachments; multi-part message bodies; and header information in non-ASCII character sets. ... A type code is a mechanism used in pre-Mac OS X versions of the Macintosh operating system to denote a files format, in a manner similar to file extensions in other operating systems. ... A Uniform Type Identifier (UTI) is a string that uniquely identifies the type of a class of items. ... Suppose the smiley face in the top left corner is an RGB bitmap image. ... For the journal by ACM SIGGRAPH, see Computer Graphics (Publication). ... This article does not cite any references or sources. ... See also Category:Graphics file formats Here is a summary of the most common graphics file formats: Some file formats, e. ... A digital image is a representation of a two-dimensional image as a finite set of digital values, called picture elements or pixels. ... â€œProgrammingâ€ redirects here. ... A bit array (or bitmap, in some cases) is an array data structure which compactly stores individual bits (boolean values). ... This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ... Suppose the smiley face in the top left corner is an RGB bitmap image. ...

In some contexts, the term bitmap implies one bit per pixel, while pixmap is used for images with multiple bits per pixel.^[1]^[2]

Many graphical user interfaces use bitmaps in their built-in graphics subsystems;^[3] for example, the Microsoft Windows and OS/2 platforms' GDI subsystem, where the specific format used is the Windows and OS/2 bitmap file format, usually named with the file extension of .BMP (or .DIB for device-independent bitmap). Besides BMP, other file formats that store literal bitmaps include InterLeaved Bitmap (ILBM), Portable Bitmap (PBM), X Bitmap (XBM), and Wireless Application Protocol Bitmap (WBMP). Most other image file formats, such as JPEG, TIFF, PNG, and GIF, to name just a few, also do ultimately store bitmap images (as opposed to vector images), but they are not as often called bitmaps, since they use compressed formats internally. A graphical user interface (GUI) is a type of user interface which allows people to interact with a computer and computer-controlled devices which employ graphical icons, visual indicators or special graphical elements called widgets, along with text labels or text navigation to represent the information and actions available to... Windows redirects here. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... GDI is short for Graphics Device Interface or Graphical Device Interface, and is one of the three core components or subsystems of Microsoft Windows. ... A filename extension or filename suffix is an extra set of (usually) alphanumeric characters that is appended to the end of a filename to allow computer users (as well as various pieces of software on the computer system) to quickly determine the type of data stored in the file. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ... The portable pixmap file format (PPM), the portable graymap file format (PGM) and the portable bitmap file format (PBM) specify rules for exchanging graphics files. ... In computer graphics, the X Window System uses X BitMap (XBM), an ASCII text monochrome image format, for storing cursor and icon bitmaps used in the X GUI. XBM files differ markedly from most image files in that they take the form of C language source files. ... Wireless Application Protocol Bitmap Format (shortened to Wireless Bitmap and with file extension . ... JPG redirects here. ... This article is about TIFF, the computer image format. ... PNG may stand for: Persona non grata, literally meaning an unwelcome person, is a term used in diplomacy with a specialised and legally defined meaning. ... An example of a GIF image. ... Image compression is the application of Data compression on digital images. ...

Pixel storage

Uncompressed bitmap files (such as BMP) are typically much larger than compressed (with any of various methods) image file formats for the same image. For example, the 1058×1058 Wikipedia logo, which occupies about 287.65 KB in the PNG format, takes about 3281.5 KB as a 24-bit BMP file. Uncompressed formats are generally unsuitable for transferring images on the Internet or other slow or capacity-limited media. This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ... Color depth is a computer graphics term describing the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. ... Indexed color is a type of color space for digital images. ... In computer graphics, alpha compositing is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image in a process called compositing. ... Transparency is possible in a number of graphics file formats. ... In computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample. ... Windows XP is a line of operating systems developed by Microsoft for use on general-purpose computer systems, including home and business desktops, notebook computers, and media centers. ... Image editing encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations. ... â€œPhotoshopâ€ redirects here. ... It has been suggested that this article be split into articles entitled Adobe Flash Player and Talk:Adobe Flash #Merger proposal, accessible from a disambiguation page. ... Image compression is the application of Data compression on digital images. ... Image File history File links Download high resolution version (1058x1058, 477 KB) aa Wikipedia logo, version 1058px square, no text Wikipedia logo by Nohat (concept by Paullusmagnus); compare Wikipedia File links The following pages link to this file: Arabic language Talk:Anarcho-capitalism Talk:Algorithm Talk:Anno Domini Talk:The... A kilobyte (derived from the SI prefix kilo-, meaning 1000) is a unit of information or computer storage equal to the decimal 1024 bytes (2 to the 10th power, or 1,024 bytes based in the binary system). ... PNG may stand for: Persona non grata, literally meaning an unwelcome person, is a term used in diplomacy with a specialised and legally defined meaning. ... A kilobyte (derived from the SI prefix kilo-, meaning 1000) is a unit of information or computer storage equal to the decimal 1024 bytes (2 to the 10th power, or 1,024 bytes based in the binary system). ...

The bits representing the bitmap pixels may be packed or unpacked (spaced out to byte or word boundaries), depending on the file format. Depending on the color depth, a pixel in the picture will occupy at least n/8 bytes (n is the bit depth, since 1 byte equals 8 bits). Data Structure Alignment is the way data is arranged and accessed in computer memory. ...

For a BMP (uncompressed, packed within rows) file, the approximate size for a n-bit (2ⁿ colors) bitmap in bytes can be calculated as: In computer science a byte (pronounced bite) is a unit of measurement of information storage, most often consisting of eight bits. ...

size of BMP file $approx 54+4 cdot 2^n+frac{width cdot height cdot n}{8}$ , where height and width are given in pixels. A pixel (a contraction of picture element) is one of the many tiny dots that make up the representation of a picture in a computers memory. ...

In the formula above, 54 is the size of the header of the bitmap file. And $4 cdot 2^n$ is the size of the color palette. Notice that this is an approximation, as for an n-bit bitmap image, although there can be maximum

2 n

colors, a specific image may not use all of these colors. Since the color palette only defines the colors that are used by the image, the actual size of the color palette will be smaller than $4 cdot 2^n$ . Also, only 8-bit (or less) bitmaps use a palette. For 16-bit (or higher) bitmaps, omit the palette part from the size calculation: In information technology, Header refers to supplemental data placed at the beginning of a block of data being stored or transmitted, which contain information for the handling of the data block. ... A palette, in computer graphics, is a designated subset of the total range of colors supported by a computer graphics system. ...

Due to effects of dword padding (if the number of bytes matching a horizontal line in the image does not form multiple dwords, i.e. divisible by 4, null bytes are added), the term describing the raw image size is approximated and the calculated size will be slightly different from the actual file size. For detailed information, see the sections on file format below. In computer science, a dword is a unit of data that is twice the size of a word and half the size of a qword. ...

BMP file format

The following sections discuss the data stored in the BMP file in details. This is the standard BMP file format.^{[citation needed]} Some bitmap images may be stored using a slightly different format, depending on the application that creates it. Also, not all fields are used; a value of 0 will be found in these unused fields.

BMP header

This block of bytes is added before the BMP format used internally by GDI and serves for identification. A typical application will read this block first to ensure that the file is actually a BMP file and that it is not damaged.

In computer programming, a magic number is a constant used to identify the file or data type employed. ... Image:ASCII fullsvg There are 95 printable ASCII characters, numbered 32 to 126. ... In computer science, a dword is a unit of data that is twice the size of a word and half the size of a qword. ... In computer science, an offset within an array or other data structure object is an integer indicating the distance (displacement) from the beginning of the object up until a given element or point, presumably within the same object. ...

Bitmap information

This block of bytes tells the application detailed information about the image, which will be used to display the image on the screen. It also matches the header used internally by Windows and OS/2 and thus has several different variants. All of them start with a dword field, specifying their size in bytes, so that an application can easily determine the exact format used. The new header variants were introduced with new versions of Windows and OS/2, adding more functionality to the GDI. But since these extended headers are used only with few GDI functions, for compatibility with older programs most applications use the older headers when saving files. With OS/2 being obsolete, for now the only common format is the Windows 3.0 V3 header. See the table below for more information about the variants. In computer science, a dword is a unit of data that is twice the size of a word and half the size of a qword. ...

The V3 header: Windows 3. ... Windows 3. ... Windows 95 is a consumer-oriented graphical user interface-based operating system. ... Windows NT 4. ...

The compression method field (bytes #30-33) can have the following values:^[4] The metre, or meter (symbol: m) is the SI base unit of length. ...

The OS/2 V1 header is also popular:^[5] Run-length encoding (RLE) is a very simple form of data compression in which runs of data (that is, 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 run. ... A bit field is a common idiom used in computer programming to store a set of Boolean datatype flags compactly, as a series of bits. ... JPG redirects here. ... PNG may stand for: Persona non grata, literally meaning an unwelcome person, is a term used in diplomacy with a specialised and legally defined meaning. ...

Color palette

This block of bytes define the colors being used inside an indexed-color image. As stated above, the bitmap picture will be stored pixel by pixel. Each pixel is described by a value which will be stored using one or more bytes. Therefore, the purpose of the color palette in indexed-color bitmaps is to tell the application the actual color that each of these values corresponds to.

A typical bitmap file uses the RGB color model. In this model, a color is created by mixing different intensities (which can vary from 0 to 255) of red (R), green (G) and blue (B). A color is thus defined using the 3 values for R, G and B. REDIRECT RGB color model ...

In the bitmap file implementation, the color palette contains many entries; the number of entries is the number of colors used in the picture. Each entry contains 4 bytes for a Windows bitmap and 3 bytes for an OS/2 bitmap. The first (and only for OS/2) 3 bytes store the values for blue, green and red respectively while the last one is unused and is filled with 0 by most applications. For each byte, a value of 0 indicates that the corresponding color (either red, green, or blue) is not used to create the current image color. On the other hand, a value of 255 indicates that maximum intensity is used.

As mentioned above, the color palette is not used when the bitmap is 16-bit or higher.

Bitmap data

This block of bytes describes the image, pixel by pixel. Pixels are stored starting in the bottom left corner going from left to right and then row by row from the bottom to the top. Each pixel is described using one or more bytes. If the number of bytes matching a horizontal line in the image is not divisible by 4, the line is padded with null-bytes. The null character (also null terminator) is a character with the value zero, present in the ASCII and Unicode character sets, and available in nearly all mainstream programming languages. ...

Miscellaneous

The simplicity of BMP and its widespread familiarity in Windows and elsewhere, as well as the fact that this format is well-documented and free of patents, makes it a very common format that image processing programs from many operating systems can read and write. In general terms, documentation is any communicable material (such as text, video, audio, etc. ... For other uses, see Patent (disambiguation). ...

While BMP files have a relatively large file size, many BMP files can be considerably compressed with lossless data compression algorithms such as ZIP because they contain redundant data. Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. ... The ZIP file format is a popular data compression and archival format. ...

Related formats

The X Window System uses a similar XBM format for black-and-white images, and XPM (pixelmap) for color images. There are also a variety of RAW formats, which saves raw data with no other information. The Portable Pixmap (PPM) and Truevision TGA formats also exist, but are less often used - or only for special purposes. For example, TGA can contain transparency information. â€œX11â€ redirects here. ... In computer graphics, the X Window System uses X BitMap (XBM), an ASCII text monochrome image format, for storing cursor and icon bitmaps used in the X GUI. XBM files differ markedly from most image files in that they take the form of C language source files. ... Black-and-white or black and white) can refer to a general term used in photography, film, and other media (see black-and-white). ... X Pixmap (XPM) is an ASCII-text-based image format used by the X Window System. ... Color is an important part of the visual arts. ... A raw image file contains minimally processed data from the image sensor of a digital camera or image scanner. ... For other uses, see Data (disambiguation). ... The ASCII codes for the word Wikipedia represented in binary, the numeral system most commonly used for encoding computer information. ... The portable pixmap file format (PPM), the portable graymap file format (PGM) and the portable bitmap file format (PBM) specify rules for exchanging graphics files. ... Truevisions (now Pinnacle Systems) TGA File Format, often referred to as TARGA File Format, is a raster graphics file format. ...

See also

This is a comparison of graphics file formats. ... Windows Picture and Fax Viewer is an image viewer. ... Microsoft Paint (officially titled Paint; sometimes called MS Paint; formerly Paintbrush for Windows) is a simple graphics painting program that has been included with all versions of Microsoft Windows since its first release. ...

References

External links

Categories: Articles needing additional references from September 2007 | All articles with unsourced statements | Articles with unsourced statements | Graphics file formats | Windows multimedia This article does not cite any references or sources. ... â€œSource codingâ€ redirects here. ... Video compression refers to making a digital video signal use less data, without noticeably reducing the quality of the picture. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... Motion JPEG, also known as M-JPEG, is a video file format consisting of a sequence of individual JPEG images; unlike other video compression algorithms, each frame is an image unto itself. ... MPEG-1 defines a group of Audio and Video (AV) coding and compression standards agreed upon by MPEG (Moving Picture Experts Group). ... MPEG-2 is a standard for the generic coding of moving pictures and associated audio information [1]. It is widely used around the world to specify the format of the digital television signals that are broadcast by terrestrial (over-the-air), cable, and direct broadcast satellite TV systems. ... MPEG-4 Part 2 is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standard (ISO/IEC 14496-2). ... H.264 is a standard for video compression. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... H.261 is an 1990 ITU video coding standard originally designed for transmission over ISDN lines on which data rates are multiples of 64 kbit/s. ... H.262 is an ITU-T digital video coding standard. ... H.263 is a video codec designed by the ITU-T as a low-bitrate encoding solution for videoconferencing. ... H.264 is a standard for video compression. ... Audio Video Standard, or AVS, is a compression codec for digital audio and video, and a possible alternative to H.264/AAC/Vorbis [1], meant to potentially replace MPEG-2. ... Bink is a video file format (extension . ... Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video. ... Indeo Video (commonly known now simply as Indeo) is a video codec developed by Intel in 1992. ... Motion JPEG (M-JPEG) is an informal name for multimedia formats where each video frame or interlaced field of a digital video sequence is separately compressed as a JPEG image. ... RealVideo is a proprietary video format developed by RealNetworks. ... Theora is a video codec being developed by the Xiph. ... VC-1 is the informal name of the SMPTE 421M video codec standard initially developed by Microsoft. ... TrueMotion VP6 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3 and VP5. ... TrueMotion VP7 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3, VP5 and TrueMotion VP6. ... Windows Media Video (WMV) is a generic name for the set of video codec technologies developed by Microsoft. ... Audio compression is a form of data compression designed to reduce the size of audio files. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... For other uses, see MP3 (disambiguation). ... MPEG-1 Audio Layer II (MP2, sometimes Musicam) is an audio codec defined by ISO/IEC 11172-3. ... MPEG-1 Audio Layer I, commonly abbreviated to MP1, is one of three audio codecs included in the MPEG-1 standard. ... MPEG-4 AAC DRM encoding as used in the iTunes Store Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. ... High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. ... High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... G.711 is an ITU-T standard for audio companding. ... G.722 is a ITU-T standard wideband speech codec operating at 32-64 kbit/s. ... G.722. ... Adaptive Multi Rate - WideBand or AMR-WB is a speech coding standard developed after the AMR using same technology like ACELP. The codec provides excellent speech quality due to wider speech bandwidth of 50 - 7000 Hz compared to narrowband speech codecs which in general are optimized for POTS wireline quality... This article is in need of attention from an expert on the subject. ... G.723. ... G.726 is ITU-T speech codec operating at bit rates of 16-40 kbit/s. ... G.728 is a ITU-T standard for speech coding operating at 16 kbit/s. ... G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ... Dolby Digital is the marketing name for a series of lossy audio compression technologies by Dolby Laboratories. ... Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec, ALAC) is an audio codec developed by Apple Inc. ... Adaptive Transform Acoustic Coding (ATRAC) is a family of proprietary audio compression algorithms developed by Sony. ... Free Lossless Audio Codec (FLAC) is a popular file format for audio data compression. ... internet Low Bit Rate Codec (iLBC) is a royalty free narrowband speech codec, developed by Global IP Sound (GIPS). ... Monkeyâ€™s Audio is a file format for audio data compression. ... In telecommunication, a mu-law algorithm (Î¼-law) is a standard analog signal compression or companding algorithm, used in digital communications systems of the North American and Japanese digital hierarchies, to optimize (in other words, modify) the dynamic range of an audio analog signal prior to digitizing. ... Musepack or MPC is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160-180 kbit/s. ... Nellymoser is a single-channel (mono) format optimized for low-bitrate transmission of audio. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... RealAudio is a proprietary audio format developed by RealNetworks. ... SHN (Shorten) is a file format used to losslessly compress CD-quality audio files (44. ... Speex is a free software speech codec that may be used on VoIP applications and podcasts. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ... WavPack is a free, open source lossless audio compression format developed by David Bryant. ... Windows Media Audio (WMA) is an audio data compression technology developed by Microsoft. ... TAK (Toms lossless Audio Kompressor) is a lossless audio compressor which promises compression performance similar to Monkeys Audio â€œHighâ€ and decompression speed similar to FLAC. The codec also supports streaming (necessary headers for decompressing the audio are written to the stream every 2 seconds), error tolerance (single bit... Image compression is the application of Data compression on digital images. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... JPG redirects here. ... JPEG 2000 is a wavelet-based image compression standard. ... The Joint Photographic Experts Group, in addition to their well-known lossy image compression techniques, JPEG and JPEG 2000, also have three standards for lossless compression (of which JPEG-LS has a lossy mode): Lossless JPEG was developed as a late addition to JPEG in 1993, using a completely different... JBIG is a lossless image compression standard from the Joint Bi-level Image Experts Group, standardized as ISO/IEC standard 11544 and as ITU-T recommendation T.82. ... JBIG2 is an image compression standard for bi-level images, developed by the Joint Bi-level Image Experts Group. ... PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ... Wireless Application Protocol Bitmap Format (shortened to Wireless Bitmap and with file extension . ... .BMP or . ... GIF (Graphics Interchange Format) is a bitmap image format that is widely used on the World Wide Web, both for still images and for animations. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ... PCX is an image file format that uses a simple form of run-length encoding (a type of lossless compression algorithm). ... PGF (Progressive Graphics File) is a wavelet-based bitmapped image format that employs lossless and lossy data compression. ... Truevisions (now Pinnacle Systems) TGA File Format, often referred to as TARGA File Format, is a raster graphics file format. ... â€œTIFFâ€ redirects here. ... HD Photo (formerly Windows Media Photo) is a still image compression algorithm and file format for continuous tone photographic images, developed by Microsoft as a part of the Windows Media family. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... 3GP is a multimedia container format defined by the Third Generation Partnership Project (3GPP) for use on 3G mobile phones. ... Advanced Systems Format (formerly Advanced Streaming Format) is Microsofts proprietary digital audio/digital video container format, especially meant for streaming media. ... // Audio-Video Interleaved, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. ... DivX is a video codec created by DivX, Inc. ... DPX is also the name given to a mounting medium, see Di-n-butylPhthalate in Xylene. ... Flash Video (FLV) is a proprietary file format used to deliver video over the Internet using Adobe Flash Player (formerly known as Macromedia Flash Player) version 6, 7, 8, or 9. ... // The Matroska Multimedia Container is an open standard free multimedia container format that can hold an unlimited number of video, audio, picture or subtitle tracks inside a single file. ... MPEG-4 Part 14, formally ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. ... Material eXchange Format (MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards. ... NUT is a patent-free, multimedia container format originally conceived by a few MPlayer and FFmpeg developers that were dissatisfied with the limitations of all currently available multimedia container formats such as AVI or Matroska. ... Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. ... Ogg Media (OGM), meaning Ogg Media File, is a container format (for video, audio and subtitle streams). ... QuickTime is a multimedia framework developed by Apple Inc. ... RealMedia is a multimedia container format created by RealNetworks. ... A VOB file (DVD-Video Object or Versioned Object Base) is a container format contained in DVD-Video media. ... Audio Interchange File Format (AIFF) is an audio file format standard used for storing sound data for personal computers and other electronic audio devices. ... The Au file format is a simple audio file format that consists of a header of 6 32-bit words and then the data (high-order byte comes first). ... WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. ...

Contents

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