In what formats can created graphic images be saved? Recommendations for using different raster graphics formats
Which store any type of persistent graphical data (“images”) intended for subsequent visualization. The ways of organizing these files are called graphic formats. Once written to a file, the image ceases to be an image itself - it turns into digital data. The format of this data may change as a result of file conversion operations. Depending on the nature of the graphics supported, file formats are classified into one of the following types: raster format, vector format, metafile format. Most common graphic formats:
AI (Adobe Illustrator, Adobe AI) - a metafile format developed by Adobe for Macintosh, Microsoft Windows, NeXT; used for recording and storing various types of images, including drawings, drawings and decorative inscriptions.
PSD (Photoshop Document, Adobe Photoshop, Adobe PSD) - a raster format included in the Adobe Photoshop graphics editor; used by publishing systems on PC and Macintosh platforms. PSD allows you to record with or without compression (RLE) an image with many layers, masks, additional channels, contours and other graphic elements.
ART is a format developed by Gonson-Grace, used for storing photographs and drawings.
AutoCAD DXF (Drawing Interchange Format) and AutoCAD DXB (Drawing Interchange Binary) are two versions of the same format (without data compression), developed and supported by Autodesk for the AutoCAD CAD program running on the MS-DOS platform. DXB is a simplified (binary) version of the seven-bit DXF. In addition to AutoCAD, the format is supported by many CAD programs, CorelDRAW and others, in particular, for exchanging data of different types: vector-oriented data, texts, three-dimensional drawings. However, a number of programs that claim to support DXF import implement only some of its capabilities. DXF changes with each version of AutoCAD. DXF and DXB file names use the extensions *.dxf, *.dxb, *.sld, *.adi.
BDF (Bitmap Distribution Format) is a raster format developed by the X Consortium for exchanging bitmap font data between X Window and other systems. No compression maximum size images are not limited, color is monochrome. Each BDF file stores data for only one typeface (a group of fonts united by a single name).
BMP is a raster format developed by Microsoft for Windows OS; supported by all graphic editors working under its control, capable of storing both indexed (up to 256 colors) and RGB color (16.7 million shades). Most BMP files are stored in uncompressed form.
CDR (CorelDRAW Document) is a vector format originally known for its low stability and poor compatibility files. Many PC programs (FreeHand, Illustrator, PageMaker) can import CDR files. Starting from the seventh version, CorelDRAW in CDR files applies compression separately for vector and raster graphics; fonts can be embedded.
CGM (Computer Graphics Metafile) is a standard (ANSI and ISO) and metafile format for displaying vector images on the Web, adopted at the end of 1998 by the 3WC (WWW Consortium). The format is focused on supporting a variety of graphic images, including artistic graphics, technical illustrations, cartography, and computer publishing systems. Although CGM contains many graphics primitives and attributes, it is less complex than PostScript, allows for the creation of more compact files, and supports the exchange of complex, high-quality artistic images. The format uses different types of compression (RLE, CCITT Group 3 and Group 4); the color palette is not limited. One CGM file can contain multiple images.
CPT is a raster format of the Corel PHOTO-PAINT program, provides storage of full-color images and vector objects.
DPX (Digital Picture Exchange Format; also known as SMPTE Digital Picture Exchange Format) is a raster format designed to store one film frame or video data stream; developed by Kodak Cineon, adopted by ANSI and the US Society of Motion Picture and Television Engineers (SMPTE) with minor modifications as a standard. The format is supported by Kodak programs.
DWG is a vector format of the AutoCAD program from Autodesk, designed for storing drawings.
EMF (Enchanced Metafile) is a metafile format developed by Microsoft for storing images as a sequence of commands leading to the reproduction of images. In November 2005, the vulnerability of EMF and WMF formats from “buffer overflow attacks” was discovered, and at the end of December, a family of Internet worms appeared. The infection occurred when users visited a number of sites that used the WMF vulnerability to download Trojan programs to remote machine. Soon, stand-alone versions of viruses appeared, spreading in the form of email worms in attached image files. Microsoft responded to this threat by issuing Security Advisory 912840 and (January 11, 2005) hotfix Windows systems XP, Windows 2000 (Service Pack 4), Windows Server 2003.
3DS (3D Studio, ASC) - a format developed by Autodesk, a three-dimensional modeling tool (“scene description”); also used as an interchange format. The format ensures optimal distribution of resources on the PC platform, supports all colors without restrictions, and has no compression. Many 3D modeling programs read and write files in this format. Strictly speaking, 3DS is two formats that are used as exchange formats - binary with the *.3ds extension and text with the *.asc extension.
EPS (Encapsulated PostScript, EPSF) is a simplified version of the PostScript format (PDL), developed by Adobe as a vector format, and later its raster version appeared - Photoshop EPS. The EPS format cannot contain more than one page in a single file and does not preserve a number of printer settings. Like PostScript print files, the EPS format records the final work, although programs such as Adobe Illustrator, Photoshop and Macromedia FreeHand can use it as a production tool.
FH8 (FreeHand Document) is the eighth version of the FH format, intended only for Macintosh PCs. The FreeHand program itself, Illustrator 7 and limited number programs from Macromedia. Starting from the seventh version, the FH format has full cross-platform compatibility, however, some FreeHand effects are not compatible with PostScript.
FIF (Fractal Image Format) is a format developed by Iterated Systems, used for storing photographs on the Internet, and supports its own FIF compression system.
FITS (Flexible Image Transport System, FTI) is a raster format and image storage standard used by many organizations (including scientific organizations, government agencies) for storing astronomical (obtained by orbital vehicles) and terrestrial images (in particular, radio astronomy data and digitized photographic images) . The format is widely used to exchange data between different hardware platforms and software applications that do not support a common file format. FITS is considered a fairly simple, uncompressed format with an “unlimited number” of shades of gray. It can store many types of data, including raster, ASCII text, multidimensional matrices, binary tables.
GIF (Graphics Interchange Format) is a standard raster format for presenting images on the WWW; was developed in 1987 by CompuServe, overshadowing the older PCX and MacPaint formats. Main advantages: the ability to use on many platforms and the availability of an efficient 12-bit LZW compression algorithm with free (until 1994) implementations. The format allows you to well compress files in which there are a lot of uniform fills (logos, inscriptions, diagrams), record an image “through the line” (Interlaced mode), thanks to which, having only part of the file, you can see the entire image, but with a lower resolution (GIF supports resolution up to 66536x65536).
IFF (Interchange File Format), ILM, ILBM, LBM (InterLeaved BitMap), Amiga Paint - a family of raster formats developed and supported for the MS-DOS, UNIX, Amiga platforms by Electronics Arts and Commodore-Amiga. A distinctive feature of IFF is its versatility: it can be used not only to support graphics, but also sound on all platforms except Amiga. IFF was previously known as the 24-bit format for MS-DOS, but it began to be replaced by the TIFF and TGA formats, and then by the JFIF format. Some characteristics of the IFF format: maximum image size 64 K by 64 K pixels; used in uncompressed and RLE compression versions, supports colors from 1- to 24-bit; “Major in Minor” number format, has a specification on CD; when used with MS-DOS and UNIX, file names may have *.iff and *.lbm extensions.
JFIF (JPEG File Interchange Format), JFI, JPG, JPEG - a raster format from C-Cube Microsystems, has become most widespread, so most “JPEG” images would be more correctly called “JFIF”. Using JFIF, it is recommended to save only the final version of the work, since each intermediate save leads to data loss and distortion of the original image.
PCX (PC Paintbrush File Format) is one of the most common raster formats; designed for storing illustrations in desktop publishing systems. The format was developed by Zsoft for the Paintbrush program, and after concluding an OEM agreement with Microsoft Corporation, it began to be used in different systems working with graphics. Main characteristics: maximum image size 64 K by 64 K; 24-bit color support; uses RLE compression (can work without compression); supports work with CD-ROM. The PCX format versions are DCX and PCC, whose file names have the appropriate extension.
PDF (Portable Document Format) is a metafile format proposed by Adobe for graphic files (vector and raster) containing illustrations and text with a large set of fonts and hypertext links for the purpose of transmitting them over the network in compressed form.
PDS (Planetary Data System Format) is a NASA standard format for storing data collected by spacecraft and ground-based observations about the Sun, Moon and planets; is also used by other organizations to store similar data. The basis of the format is the object description language - ODL (Object Description Language). The maximum image size and colors in PDS format are unlimited; supported on all platforms.
PGML (Precision Graphics Mark-up Language) is a vector format that describes graphics in terms mathematical formulas, rather than raster pixels, which saves disk space and allows you to scale the image without losing its resolution and other quality indicators. The format was submitted to the W3C (WWW Consortium) for consideration as network standard Adobe Systems, IBM, Netscape, Sun Macromedia; used on the Internet.
Photo-CD (PCD, Kodak Photo CD) is a raster format developed by Eastman Kodak and designed for storing and playing full-color images (usually photographs) recorded at various resolutions on CDs. Format supported Photo programs CD ACCess, Photoshop, Shoebjx. The Photo CD format supports 24-bit colors, has its own compression system, a maximum image size of 2048x3072 pixels, allows you to store only one image per file, uses RLE and JPEG compression systems (in the DCT version). More details Kodak does not disclose.
PIC (Pictor PC Paint, PC Paint) - a raster format developed by Paul Mace for drawing programs on the MS-DOS platform, is a hardware-dependent format created taking into account the requirements of the IBM family of graphics adapters (CGA, EGA, VGA). The PIC format is similar to the PCX format; the file names use the *.pic and *.clp extensions.
PICT (Macintosh QuickDraw Picture Format) is a standard for the Macintosh PC clipboard, supporting both raster and vector graphics. On a Macintosh PC, PICT works with all programs. On a PC it can be read by a number of programs, but working with it is rarely easy. PICT file names have the extension *.pic or *.pct.
PNG (Portable Network Graphics) is a raster format approved as a standard by the W3C (WWW Consortium) and intended to replace GIF. The format provides indexing of up to 256 colors, support for 24- and 48-bit color representation (True Color) and the implementation of a transparency channel (the so-called alpha channel). The dynamic lossless PNG image compression algorithm is 10-30% more efficient than a similar type of compression implemented in the GIF format.
PS (PostScript) - the format of the PostScript page description language (also known as the laser printer control language) was developed in 1984 by Adobe. The format is used for printing and storing fonts, as well as for exchanging documents formatted with it. The advantage of the PS format is that it uses a device-independent playback system (including printer or screen type).
RAF (RAW) is a raster format used in digital cameras and maintains the image directly in the form in which it was captured by the camera sensor. Using this format eliminates artifacts associated with pre-processing of the image by camera software (for example, during JPEG compression) and provides the photographer with the ability to further process photographs (adjust exposure, change color balance, increase size).
Scitex CT is a raster format developed by Scitex; differs slightly from TIFF, with the exception of one feature: on phototypesetting machines (Imagesetter) from Scitex Dolev, files of this format are output somewhat faster. On a PC, file names in the Scitex CT format have the extension *.sct.
SWF ( Shockwave Flash) is an internal vector format of the Macromedia Flash program, used for animation on the Internet.
TGA (TrueVision Targa) - a Truevision format developed for color television, supports RLE compression, file names have the *.tga extension.
TIFF (TIF, Tagged Image File Format is a raster format developed by Aldus Corporation, originally intended for large, high-resolution graphic images obtained by scanning. The format is characterized by high quality of transmission and preservation of the color of the original images. Subsequently, the format was adapted for professional graphics packages and expanded.
WMF (Windows Metafile, Microsoft Windows Metafile) is a metafile format created for use with Windows OS, used for transferring vectors via the clipboard. WMF is supported by almost all programs running under Windows and in one way or another related to vector graphics. Despite its apparent simplicity and versatility, it is recommended to use the WMF format only in extreme cases for transmitting so-called naked vectors. WMF distorts color, does not save a number of parameters that can be assigned to objects in various vector editors, and is not understood by programs targeting the Macintosh PC. WMF files use the *.wmf extension.
VML (Vector Mark-up Language) is a vector format that was submitted to the W3C consortium by Microsoft, Hewlett-Packard, Autodesk, Macromedia, Visio; used on the Internet.
The main question and topic of our article is formats. Among all the wealth of choice, there is no ideal format that would satisfy all possible requirements. Nevertheless, knowing the future fate of the file - printing, the Internet or simply printing on an inkjet printer, you can properly prepare it and, if not guarantee, then at least maintain hope for success.
All graphic information can be divided into two main groups: vector and raster. Fonts occupy a separate niche in vector graphics.
Raster graphics are a two-dimensional matrix (bitmap) consisting of elementary particles - pixels. The main parameters are size and resolution. The size can be expressed in millimeters, inches, pixels, etc., respectively, this parameter characterizes the horizontal and vertical size of the image. The second main parameter - resolution - characterizes the ratio of the number of pixels per square inch (ppi - pixels per inch or dpi - dot per inch). For newspaper printing, raster graphics should be in the range of 120-150 dpi, for high-quality printing with photo output - 250-300 dpi. Large resolution values are usually redundant and do more harm than good, slowing down the output. Screen resolution is considered to be 72 dpi (in printing it is used only for preview).
BMP(Windows Device Independent Bitmap). Windows native format. It is supported by all graphic editors running this operating system. It is used to store bitmap images intended for use in Windows and this is where its scope ends. Using BMP for purposes other than Windows is a fairly common mistake.
GIF(CompuServe Graphics Interchange Format). The hardware-independent GIF format was developed in 1987 (GlF87a) by CompuServe for transmitting raster images over networks. In 1989, the format was modified (GIF89a), support for transparency and animation was added. GIF uses LZW compression, which makes it possible to compress files with a lot of uniform fills (logos, inscriptions, diagrams) well.
JPEG(Joint Photographic Experts Group). Strictly speaking, JPEG is not a format, but a compression algorithm based not on searching for identical elements, but on the difference between pixels.
The higher the compression level, the more data is discarded, the lower the quality. Using JPEG you can get a file 1-500 times smaller than BMP! Initially, CMYK was not included in the format specifications; Adobe added support for color separations, but CMYK JPEG causes problems in many programs.
JPEG compresses photographic-quality raster images better than logos or diagrams.
TIFF, TIF(Target Image File Format). The hardware-independent TIFF format is one of the most widespread and reliable today; it is supported by almost all programs on PC and Macintosh that are somehow related to graphics. The entire range of color models is available to him from monochrome to RGB, CMYK and additional Pine colors. TIFF may contain clipping paths, alpha channels, layers, and other additional data.
In the TIFF format, it is possible to save using several types of compression: JPEG, ZIP, but, as a rule, only LZW compression is used.
EPS(Encapsulated PostScript). The format uses a simplified version of PostScript: it cannot contain more than one page in one file, and does not save a number of printer settings. EPS is designed for transferring vectors and rasters to publishing systems, and is created by almost all programs that work with graphics. It makes sense to use it only when the output is carried out on a PostScript device. EPS supports all color models required for printing.
EPS has many varieties, depending on the creator program. The most reliable EPS are created by programs produced by Adobe Systems: Photoshop, Illustrator, InDesign.
QXD(QuarkXPress Document). Working format of the well-known layout program QuarkXPress. The package is characterized by stability, speed and ease of use. The main, never defeated competitor of Adobe Systems continues to exist now in its fifth reincarnation. It should also be noted that there are still two in use previous versions QuarkXPress 3.x and QuarkXPress 4.x. The special ideology of the package lies in its ability to adapt to any layout designer’s tasks. After all, the main functions are performed special extensions(Xtensions), of which there are more than Plug-ins for Photoshop.
RM(Page Maker). Adobe Systems layout program format. An extremely simple package in terms of capabilities. It was intended primarily for the transition from manual layout to computer layout with minimal costs for staff training. It became widespread among us thanks to timely Russification and, again, ease of learning for beginners. Currently, development of the package has been stopped.
ID(InDesign). Code name "Quark Killer" A follower of RM, designed to squeeze out competitors in the publishing market, primarily Quark. A hodgepodge of solutions borrowed from other layout packages did not lead to the expected result. ID is an extremely clumsy and inconvenient package, which turned out to be the killer only of its progenitor RM, and then because of the cessation of development of the latter.
The only advantages include a built-in PostScript interpreter and apparent ultra-compatibility with other Adobe products.
PDF(Portable Document Format) - proposed by Adobe as a platform-independent format for creating electronic documentation, presentations, transferring layout and graphics over networks.
PDF files are created by converting from PostScript files or using the export function of a number of programs. The format was originally designed as a means of storing electronic documentation. Therefore, all data in it can be compressed, and in different ways: JPEG, RLE, CCITT, ZIP. PDF can also retain all of the output device information that was in the original PostScript file.
Adobe PostScript- page description language. It was created in the 80s to implement the WYSIWYG (What You See is What You Get) principle. Files in this format are actually a program with commands to execute for the output device. Such files contain the document itself, associated files, fonts used, as well as other information: color separation boards, additional boards, screen lineature and shape raster dot for each board and other data for the output device.
Data in a PostScript file is usually written in binary encoding. Binary code takes up half the space of ASCII.
CDR- format of the popular vector editor CorelDraw. The package gained its popularity and distribution due to its apparent ease of use and interactive special effects (lenses, transparencies, non-standard gradients, etc.). The wide capabilities of this program in terms of effects are explained by the richer internal page description language than that of Adobe products that use PostScript. This is precisely the main disadvantage of CorelDraw. PostScript with Korelov special effects is often a headache for printing houses and prepress bureaus.
CCX- vector graphics format from Corel. It is not supported by anything other than CorelDraw. Unsuitable for printing and the Internet. The advantages include only a small volume of files saved in this format and the presence of many excellent cliparts.
Vector graphics are a mathematical description of objects relative to an origin. Thus, to display a straight line, the coordinates of only two points are required. For a circle - coordinates of the center and radius, etc.
Graphic formats can contain a lot of additional information: alpha channels, paths, color model, raster lineature and even animation. The choice of format for printed products primarily depends on the output device. Phototypesetting machines operate under the PostScript language. Therefore, for printing, the main data storage formats are TIFF and EPS. Accordingly, the format is raster and vector graphics. IN Lately PDF (Portable Document Format) is gaining momentum.
TIFF Only suitable for transmitting raster graphics. This format allows you to store a lot of useful information: alpha channels, color model, paths and even layers (when using Adobe Photoshop 6-7). However, to increase the reliability of the output, many prepress bureaus do not recommend leaving additional channels and layers. To be on the safe side, if it is not possible to consult with the printing house, it is also better to disable compression. You shouldn't save it either text labels and vector graphics in TIFF format. Even with a resolution of 300 dpi, they will look like a sawtooth effect when printed. In order to avoid such defects, the EPS format is provided, which allows you to contain raster and vector graphics, fonts and other useful information. However, quite often we encounter this curious misconception: when opening an EPS file (created using Illustrator or Corel Drow) with the raster graphics program Photoshop, users continue to firmly believe that they are still working with vector graphics. No, my dears, no matter what format you save it in, the output you will get is only a raster and nothing more. By opening any file with vector graphics in Photoshop, you rasterize it, that is, turn it into a raster format. The only exception can be EPS created directly in Photoshop versions 6-7. Fonts and vector primitives, in this case, will remain vector in the output. This format is called Photoshop EPS. There are quite a few varieties of EPS, they differ in the presence of preview images, composite or separated images, encoding and compression. But they all agree on one thing - EPS is based on the PostScript page description language, which in turn is a standard for printing output devices. Therefore, it should be taken into account that all files in other formats, such as CDR and CCX, must be forcibly converted to PS. At the same time, commands from one language are not always adequately translated into another, and the result of such a conversion can be, at best, damaged films, or, at worst, the entire circulation. Therefore, the attitude of printing house workers towards such formats and programs is appropriate. However, this does not mean that everyone should prepare vector graphics in Illustrator and raster graphics in Photoshop; it’s just that when preparing graphics in another package, you need to limit your flight of “fantasy” and especially carefully check the output files for PostScript errors. Unlike other packages, Adobe Illustrator was designed as an interface to the PostScript language and does not need to convert its files to produce a format understandable for the output device. In the ninth and tenth versions of Illustrator, the base format is PDF, which is also not a problem for output, because it is essentially "refined" EPS. All previous versions are based on PostScript.
We should not forget about fonts. Often, only the names of fonts appear in the EPS file and others are substituted during output, which in no way corresponds to the designer’s intention. Therefore, fonts must be converted to curves, either embedded in a file, or attached as separate files.
As is known, depending on the method of image formation on the monitor screen, computer graphics are usually classified into several types:
- raster
- vector
- fractal
- three-dimensional
I think the reader already knows all this. Therefore, today we will consider the most common and popular raster graphics formats. In future publications, I plan to describe file formats for other types of computer graphics, in particular vector ones. Having described these formats, I will give my recommendations for them. practical use in everyday life, i.e. what format for what and where to use
Basics of raster graphics
Raster graphics is a graphic represented on a computer as a set of dots (pixels). Each pixel contains color information. The pixel size is very small, so the human eye perceives the entire image without dividing it into pixels.
For raster graphics important characteristic is the resolution of the image. The same picture can be presented with better and worse quality according to the number of dots (pixels) per unit length.
Permission— number of points per unit of measurement.
dpi (dots per inch)— number of dots per inch.
ppi (points/pixels per inch)- pixels per inch.
Pixel— raster point of the screen image. All images are divided into dots. Pixel is the smallest point. The image can no longer be divided. In addition, a pixel is a dot of one color; it is impossible to color half a pixel one color and the other half another.
Don't confuse image resolution, monitor resolution, and printer resolution. These are different things.
Having remembered the basics of raster graphics, let's move on to a description of raster graphics storage formats.
Image storage formats in raster graphics
File format- a method of preserving the electronic parts that make up computer file. Various formats organize saving files in different ways. I will not consider all existing raster graphics formats (and I could not); we will consider only the most common and popular ones.
BMP(Bit Map - bit carat). This format initially used the simplest encoding - pixel by pixel (the most wasteful), which was done sequentially in lines, starting from the lower left corner of the graphic image. Files of this format were included in the first versions Windows. This format used only 256 colors, i.e. a pixel is represented by only one byte. Later, the format began to be used to save full-color images. Format BMP- one for standard raster graphics formats.
TIFF (Tagged Image File Format)- a standard format in topographic graphics and publishing systems. TIFF files provide better print quality. Due to its large size, this format is not used when creating Web sites and publishing on the Internet.
Format TIFF is one of the most universal and widespread raster graphics formats. It was created as a cross-platform universal format for color images. Working with it is supported by almost all programs for working with bitmap graphics. Can store graphics in monochrome, in RGB And CMYK color representations.
The format includes internal compression. He has open architecture— it is possible to declare information about the type of image in the header, i.e. versions of it can be used in the future to present new developments. Accompanying information is also saved in the format. transmitted images(signatures, etc.). Image format TIFF are stored in files with the extension .tif.
GIF format (Graphic Interchamge Format)- a graphics data exchange format that is used for recording and storing raster graphics. This format differs from other raster graphics formats in that it has been supported on the Internet for a long time. Uses indexed colors (limited set of colors). This is one of the most common image formats distributed on the Internet and used to create Web sites.
Images in GIF .gif. To the benefits GIF The important thing about images is that the appearance of the image is independent of the browser and platform. Drawings, drawings and images with a small amount of solid color, transparent images and animation sequences (this is a very well-known feature of this graphics format) are displayed best. IN GIF Images are compressed without losing information.
JPEG format (Joint Photographic Expert Group)— designed for storing compressed images. The image compression method it uses was developed by a team of photography experts. The decoding of the abbreviation immediately becomes clear JPEG— a joint group of experts in photo processing.
JPEG is one of the most powerful image compression algorithms. In practice, it is the de facto standard for storing full-color images. Format JPEG was created in order to get rid of the restrictions that were imposed on images created in GIF format.
The algorithm operates on areas of 8? 8, in which the brightness and color changes relatively smoothly. Compression in JPEG carried out at the expense of smooth change colors in the image. Provides a high compression ratio, the value of which reaches 100 and depends on permissible level loss of visual information.
The format is widely used in documents HTML and for data transmission over the network. Saves graphics settings in color representation RGB(usually). Images in JPEG format are stored in files with the extension .jpg.
Programs that work with JPEG, use lossy compression algorithms, they exclude from the image those data that are considered unimportant. Before applying the compression algorithm, the image is divided into rectangular areas. When compressing, there is a risk of getting a fuzzy, blurry image with distortion of details.
JPEG 2000 format (jp2)
This format was developed to replace JPEG. When saving images with the same compression level, images saved in JPEG 2000, are sharper and take up less disk space. In addition, this format solves the problem with the appearance of defects JPEG, which appeared when saving with a high compression ratio (a lattice of 8 × 8 pixel blocks).
The format is not supported in all browsers, which greatly hinders the spread of this format.
PNG (portable network graphics)- a raster graphics storage format that uses lossless compression. PNG is a free format (unlike GIF), so it is widely used.
It is a very powerful and widely used format on the Internet and other areas of computer graphics.
WMF format
WMF format (Windows Metafile Format)- used to exchange graphic data between OS applications Microsoft Windows. IN WMF files can store both vector and raster images. Images in WMF format are stored in files with the extension .wmf.
PSD and CDR formats
PSD format (PhotoShop Document)— internal format for the package Adobe Photoshop. Allows you to save layers in an image and supports all types of graphics. Images in PSD format are stored in files with the extension .psd.
CDR format— internal format for the company’s software package CorelDRAW. Images and text prepared in the program CorelDRAW V CDR format, stored in files with the extension .cdr.
Recommendations for using different raster graphics formats
Now I will try to move from theory to practice and consider the areas of application of various raster graphics formats depending on their characteristics. The characteristics of the formats are as follows: the type of compression used, support for transparent colors, the ability to create simple animations, support for line-by-line image output for gradual loading in the browser, and the number of colors used in the image.
Using GIFs
Format characteristics:
- Compression support: lossless (Lempel-Ziv-Welch, LZW)
- Transparency support: Yes
- Animation support: Yes ( distinctive feature of this format)
- Yes (interlaced)
- Number of colors: indexed colors (256 colors)
- all platforms
Recommendations: it is advisable to use this format in Web, for images without smooth color transitions (logos, banners, inscriptions, diagrams). Nice guy compression and a small number of supported colors allow you to save space when storing graphics, and can also be used when creating websites for more fast loading HTML-pages. Interlaced scanning makes it possible to see and evaluate the downloaded image without waiting for the download to finish. However, the limited range of colors makes this format unsuitable for storing images with smooth transitions, gradients, etc. Mainly used on the Internet.
Using PNG
Format characteristics:
- Compression support: lossless compression (Deflate)
- Transparency support: Yes
- Animation support: Yes(APNG)
- Interlaced display support: Yes (two-dimensional interlacing)
- Number of colors: Deep Color
- Compatibility with other platforms: all platforms
Recommendations: the most advanced compression algorithm in PNG allows you to save files smaller in size than in GIF. The ability to use absolutely any color and the use of transparency make this format a leader in terms of use in Web. I would recommend using it instead GIF. Scope of application - used in design Web-sites, image editing, etc. This is a universal format with a great future.
Using JPEG
Format characteristics:
- Compression support: lossy compression
- Transparency support: absent
- Animation support: absent
- Interlaced display support: Yes (Progressive JPEG)
- Number of colors: True Color (RGB and CMYK models)
- Compatibility with other platforms: all platforms
Recommendations: This format should be used to store a large number of images (photos) on your hard drive, which will significantly save its working space (thanks to its excellent compression type). It needs to store large-sized photographs with a lot of smooth transitions. Small size of final files allows efficient use JPEG for publishing photos on the Internet. But you should not save the same images in JPEG several times - this will lead to defects and “damage” the image.
Using TIFF
Format characteristics:
- Compression Support: Supports the ability to apply various algorithms compression (depending on the image being saved)
- Transparency support: absent
- Animation support: absent
- Interlaced display support: absent
- Number of colors: 8, 16, 32 and 64 bpc (Lab, RGB and CMYK models)
- Compatibility with other platforms: all platforms
Recommendations: this powerful format is used in printing, publishing systems, etc. Files in this format are stored for future printing. TIFF Used to store scanned images, faxes, etc. illustrations.
Using BMP
Format characteristics:
- Compression support: It is possible to use lossless compression (Run Length Encoding, RLE)
- Transparency support: absent
- Animation support: absent
- Interlaced display support: absent
- Number of colors: RGB model, 24-bit color depth
- Compatibility with other platforms: Windows only
Recommendations: This format is not suitable for use in Web, typography and even for storing images (due to the lack of image compression). Used only because it is "embedded" in the OS Windows default.
Conclusion
I hope this article helped you understand a little about the variety of raster graphics formats. My recommendations will help you decide on the choice of format for storing graphics. In short, in JPEG store photos in GIF- banners and logos (but it is advisable to gradually move on to PNG), A TIFF used to prepare documents for printing.
GIF(Graphics Interchange Format)The GIF format was developed in 1987 by the computer information service CompuServe. Advantages
- Small size, which is achieved by a limited color range - no more than 256 colors.
- Transparent background.
- Animation.
The fruit of the community of independent programmers is a response to the transition of the most popular GIF format into the category of commercial products. The PNG format does almost everything that the GIF format does, except for animation. Advantages
- The best data compression - compresses raster images not only horizontally, but also vertically.
- Supports color photos graphic images up to 48-bit inclusive.
- 256 levels of transparency.
A format similar to PNG-8, but using a 24-bit color palette.
This allows you to save photographs and complex drawings in this format. Advantages
- Full color palette.
- High-quality transparency allows you to overlay the design on any background
For search the best way compression of photographic quality images, two standards organizations - the International Telecommunications Union (ITU) and the International Organization for Standardization (ISO) - created the Joint Photographic Experts Group (JPEG).
Uses lossy compression. With this compression, information that is not essential for the perception of the image is removed. WBMP(WAP BitMap)
monochrome (two-color) images.
The maximum image size should not exceed the card size limit - 1.5 KB. BMP(BitMap)
The simplest raster format, BMP, is a native Windows format. IN BMP data Color information is stored only in the RGB model, that is, this format is created for use on the screen. PCX(PCExchange)
Images in PCX format can be viewed with most DOS programs. Like BMR, this format is largely outdated and is supported by modern graphics programs solely for compatibility with antique software. TIFF, TIF(Tagged Image File Format)
Originally developed by Aldus for its PhotoStyler graphics editor. As a universal format for storing raster images, TIFF is widely used, primarily in publishing systems that require the best quality images. Due to its compatibility with most professional image processing software, the TIFF format is very convenient when transferring images between computers various types(for example, from PC to Mac and vice versa). PSD(Photoshop)
The Adobe Photoshop format is distinguished by the ability to store layers. Convenient only for processing in Photoshop and for storing the source for editing in the future. RAW(RAW Image Data)
The format is designed for digital cameras. This is an exact copy of the image captured on the matrix during shooting; it consists of three photographs taken in red, blue and green colors.
RAW file extensions may vary from manufacturer to manufacturer, and they cannot always be opened using image processing programs.
Although if a camera supports saving RAW, then, as a rule, it comes with some kind of program for processing files of this format.
Currently, Adobe has proposed the DNG (Digital Negative Specification) format, which was created in order to make life easier for manufacturers of graphics tools. Some companies (Leica and Pentax) have already included DNG in their cameras, but most camera vendors still continue to use their formats.
RAW format extensions
.dng - Adobe (generic)
.crw .cr2 - Canon
.raf - Fuji
.kdc - Kodak
.mrw - Minolta
.nef - Nikon
.orf - Olympus
.ptx .pef - Pentax
.x3f - Sigma
.arw - Sony
Vector graphics
CDR(CorelDRAW)The format of the popular CorelDRAW, which is the undisputed leader in the class of vector graphics editors on the PC platform. Having relatively low stability and problems with compatibility of files of different versions of the format. A.I.(Adobe Illustrator)
Being part of the Adobe family, they support almost all programs related to vector graphics in one way or another. The best intermediary for transferring images from one program to another, from PC to Macintosh and vice versa. It is characterized by the greatest stability and compatibility with the PostScript language, which is used by almost all publishing and printing applications. WMF(Windows Metafile)
Another native Windows format, this time vector. Understood by almost all Windows programs that are somehow related to vector graphics. EMF(Enhanced Metafile)
Similar to WMF.
OTHER FORMATS
SWF(ShokWaveFlash)Flash format, a product of Macromedia, which allows the development of interactive multimedia applications. The scope of Flash use is different, it can be games, websites, CD presentations, banners and just cartoons. When creating a product, you can use media, sound and graphic files, you can create interactive interfaces and full-fledged web applications using PHP and XML.
SVG(Scalable Vector Graphics) Standard Recommended World Wide Web Consortium for describing two-dimensional vector and combined vector-raster graphics using XML markup.
In the browser, SVG graphics are rendered using raster engines. Support for translucency in each layer, linear gradients, radial gradients, visual effects(shadows, washes, shiny surfaces, textures, patterns of any design, symbols of any complexity).
SVG is a format for 2D vector graphics as defined in the specification, but by adding script (namely JavaScript) inside an SVG file you can create 3D animated images.
SVG can have a built-in raster image, which, like any other object in SVG, can have transformation, transparency, etc. applied to it. ICO(Icon)
Icons are used in all kinds of programs on a computer and smartphone. But to an ordinary person Typically, you may need to create or use an icon on your site.
Many people are trying to start their own website. Even if you use a ready-made website template with a style that only needs to be filled in, it would still be nice for you to make a unique icon. An icon on the Internet is used as a symbol of a site, a logo. For example, now you see a red square in address bar. If you add a page of our website to your favorites, our icon will appear next to the link, which will help you quickly visually find the link to the site. Actually, this is the main purpose of an icon on the Internet.
PostScript
EPS(Encapsulated PostScript)The most reliable and in a universal way saving data. It uses a simplified version of PostScript, cannot contain more than one page in one file, and does not save a number of printer settings. Like PostScript print files, EPS records the final work, although programs such as Adobe Illustrator and Adobe Photoshop can use it as a working document. EPS is designed for transferring vectors and rasters to publishing systems, and is created by almost all programs that work with graphics.
WHICH FORMAT SHOULD I CHOOSE?
| For the Internet | |
| photograph or drawing with flowing tones | JPEG |
| picture with straight lines, small range of colors with a smooth fill (no gradient) |
GIF PNG |
| complex picture with transparent background | PNG-24 |
| animation | SWF |
| icons | ICO |
| For printing and storage | |
| For print | TIFF |
| For storage | PSD |
| For logo | EPS (CDR AI) |
| Logo for MS Office | WMF |
| For photography | |
| For storing and printing photos, but not of low quality | JPEG |
| For printing and for the original of the best quality | RAW |
INTRODUCTION
Graphic format is a way of recording graphic information. Graphics file formats are designed to store images, such as photographs and drawings.
Knowledge of file formats and their capabilities is one of the key factors in computer graphics. Yes, today there is no such kaleidoscope of extensions as in the early 90s, when each image editor manufacturing company considered it its duty to create its own file type, or even more than one, but this does not mean that “everything needs to be saved in TIFF and compressed with JPEG.” Each of the formats established today has undergone natural selection and proven its viability. They all have some characteristic features and the capabilities that make them indispensable in their work.Knowledge of the features and subtleties of technology is important for a modern designer, just as it is necessary for an artist to understand the differences in the chemical composition of paints, the properties of soils, types of metals and rocks.
These are raster graphics, vector graphics, three-dimensional and fractal graphics. They differ in the principles of image formation when displayed on a monitor screen or when printed on paper.
Raster graphics are used in the development of electronic (multimedia) and printed publications. Illustrations made using raster graphics are rarely created manually using computer programs. Most often, scanned illustrations prepared by the artist on paper or photographs are used for this purpose. Recently, digital photo and video cameras have found widespread use for inputting raster images into a computer. Accordingly, most graphic editors designed for working with raster illustrations are focused not so much on creating images, but on processing them. On the Internet, raster illustrations are used in cases where it is necessary to convey the full range of shades of a color image.
Software tools for working with vector graphics, on the contrary, are intended primarily for creating illustrations and, to a lesser extent, for processing them. Such tools are widely used in advertising agencies, design bureaus, editorial offices and publishing houses. Design work based on the use of fonts and simple geometric elements is much easier to solve using vector graphics. There are examples of highly artistic works created using vector graphics, but they are the exception rather than the rule, since the artistic preparation of illustrations using vector graphics is extremely complex.
Three-dimensional graphics are widely used in engineering programming, computer modeling of physical objects and processes, animation, cinematography and computer games.
Software tools for working with fractal graphics are designed to automatically generate images through mathematical calculations. Creating a fractal artistic composition is not about drawing or design, but about programming. Fractal graphics are rarely used to create printed or electronic documents, but they are often used in entertainment programs.
The purpose of this test will be an initial study of graphic files and their formats, information compression methods, as well as an analysis of the work done.
The objective of this test will be to determine whether a graphic format belongs to a specific subtype: vector, raster, complex.
Information compression methods
Almost all modern graphic file formats use some kind of information compression method, therefore, for a better understanding of further material, the beginning of this section contains summary these methods.
Information compression methods:
One of the simplest compression methods is the RLE (Run Length Encoding) method. The RLE method works by searching for identical pixels in the same row. If a line, say, has 3 white pixels, 21 black, then 14 white, then using RLE makes it possible not to remember each of them (38 pixels), but to write it as 3 white, 21 black and 14 white in the first line .
The LZW (Lempel-Ziv-Welch) compression method was developed in 1978 by Lempel and Ziv, and later refined in the USA. Compresses data by searching for identical sequences (called phrases) throughout the file. The identified sequences are stored in a table and are assigned shorter markers (keys). So, if an image contains sets of pink, orange and green pixels repeating 50 times, LZW detects this, assigns this set single number (for example, 7) and then stores this data 50 times as the number 7. The LZW method, like RLE, performs better in areas of uniform, noise-free colors, and it performs much better than RLE at compression arbitrary graphics data, but the encoding and decompression process is slower.
The Huffman compression method was developed in 1952 and is used as a component in a number of other compression schemes, such as LZW, Deflation, JPEG. The Huffman method takes a set of symbols and analyzes them to determine the frequency of each symbol. The most frequently occurring characters are then represented in the smallest possible number of bits. For example, the letter "e" is most often found in English texts. Using Huffman encoding, you can represent "e" with just two bits (1 and 0), instead of the eight bits needed to represent the letter "e" in ASCII.
The CCITT (International Telegraph and Telephone Committie) compression method was developed for facsimile transmission and reception. It is a narrower version of Huffman coding. CCITT Group 3 is identical to the fax message format, CCITT Group 4 is the fax format, but without special control information.
Graphics file formats
Raster format
Raster images are formed in the process of scanning multi-color illustrations and photographs, as well as when using digital photo and video cameras. You can create a raster image directly on your computer using a raster graphics editor.
A raster image is created using dots of different colors (pixels) that form rows and columns. Each pixel can take on any color from a palette containing tens of thousands or even tens of millions of colors, so raster images provide highly accurate color and grayscale reproduction. The quality of a raster image increases with increasing spatial resolution (the number of pixels in the image horizontally and vertically) and the number of colors in the palette.
The disadvantage of raster images is their large information volume, since it is necessary to store the color code of each pixel.
Let's look directly at the extensions of the raster graphics format:
1) The BMP file format (short for BitMaP) is the native raster graphics format for Windows because it most closely matches the native Windows format in which that system stores its raster arrays. The filename extension most often used in BMP format is BMP, although some files have the extension RLE, which stands for run length encoding. The RLE extension of a file name usually indicates that the file's raster information has been compressed using one of two RLE compression methods that are valid for BMP format files.
In BMP files, the color information of each pixel is encoded into 1, 4, 8, 16, or 24 bits (bits/pixel). The number of bits per pixel, also called color depth, determines the maximum number of colors in an image. An image with a depth of 1 bit/pixel can have only two colors, and with a depth of 24 bit/pixel - more than 16 million different colors.
2) PCX became the first standard graphics file format for storing raster graphics files on IBM PCs. This format, used in the ZSoft Paintbrush program, was used in the early 80s. Microsoft acquired a license and then distributed it along with Microsoft products. The format was later converted into Windows Paintbrush and began to be distributed on Windows. Although the use of this popular format is declining, PCX files, easily recognized by their PCX extension, are still widely used today.
PCX files are divided into the following three parts: a PCX header, raster array data, and an optional color table. The 128-byte PCX header contains several fields, including the image size and the number of bits to encode color information for each pixel. The raster array information is compressed using the simple RLE compression method; An optional color table at the end of the file contains 256 RGB color values that define the colors of the image. The PCX format was originally developed for CGA and EGA display adapters and has been modified for use in VGA and true color adapters. The color coding of each pixel in modern PCX images can be done at 1, 4, 8, or 24 bit depth.
3) If PCX is one of the easiest raster graphics formats to decode, then TIFF (Tagged Image File Format) is one of the most complex. TIFF files have the extension TIFF. Each file begins with an 8-byte Image File Header (IFH), the most important element of which, the Image File Directory (IFD), serves as a pointer to the data structure. An IFD is a table for identifying one or more variable length pieces of data called tags; tags store information about an image. The TIFF file format specification defines over 70 different types of tags. For example, one type of tag stores information about the width of the image in pixels, while another stores information about its height. The third type tag stores a color table (if necessary), and the fourth type tag contains the raster array data itself. An image encoded in a TIFF file is defined entirely by its tags, and the file format is easily extensible because additional tag types can be defined to add additional properties to the file.
So what makes TIFF so difficult? On the one hand, writing programs that distinguish between all types of tags is not an easy task. Most TIFF file readers implement only a subset of the tags, which is why a TIFF file created by one program sometimes cannot be read by another. Additionally, programs that create TIFF files can define their own tag types that are meaningful only to them. TIFF file readers can skip tags they don't understand, but there is always the danger that this will affect the appearance of the image.
Another complication is that a TIFF file may contain multiple images, each with its own IFD and set of tags. The raster array data in a TIFF file can be compressed using any of several methods, so a reliable TIFF file reader should have decompressors RLE, LZW (LempelZivWelch), and several others. The situation is further aggravated by the fact that the use of LZW unpacking programs must be carried out in accordance with license agreement with Unisys Corp. for the right to use the LZW algorithm and often for a fee. As a result, even the most best programs TIFF readers often fail when faced with an LZW-compressed image.
Despite its complexity, the TIFF file format remains one of the best for transferring raster arrays from one platform to another due to its versatility, which allows almost any image to be encoded in binary form without losing its visual or any other attributes.
4) Most of the leading graphics professionals dealing with the LZW algorithm face similar legal problems when using the popular cross-platform raster graphics file format GIF (Graphics Interchange Format, pronounced "gif"), developed by CompuServe. GIF files are typically named using the GIF extension, and thousands of them are available from CompuServe.
The structure of a GIF file depends on the version of the GIF specification that the file conforms to. There are currently two versions in use, GIF87a and GIF89a. The first one is simpler. Regardless of the version number, a GIF file begins with a 13-byte header containing a signature that identifies the file as a GIF, the GIF version number, and other information. If the file stores only one image, following the header there is usually a general color table that defines the colors of the image. If several images are stored in a file (the GIF format, similar to TIFF, allows you to encode two or more images in one file), then instead of a general color table, each image is accompanied by a local color table.
5) The PNG (Portable Network Graphic, pronounced "ping") format was developed to replace GIF in order to bypass the legal barriers to the use of GIF files. PNG inherits many of the features of GIF and, in addition, it allows you to store true color images. More importantly, it compresses raster array information using a variant of the highly respected LZ77 compression algorithm (predecessor to LZW), which anyone can use for free.
6) Format JPEG file Joint Photographic Experts Group (pronounced "japeg") was developed by C-Cube Microsystems as an efficient method for storing images with high color depth, such as those obtained by scanning photographs with numerous subtle (and sometimes elusive) tones. The biggest difference between JPEG and the other formats discussed here is that JPEG uses a lossy compression algorithm (rather than a lossless algorithm) to compress information. The lossless compression algorithm preserves image information so that the decompressed image exactly matches the original Lossy compression sacrifices some of the image information to achieve a higher compression ratio.The decompressed JPEG image rarely matches the original exactly, but very often the differences are so small that they are barely (if at all) detectable.
Vector format
In this subsection we will look at the most common extensions for vector graphics files.
1) Encapsulated PostScript (EPS) - an extension of the PostScript format, data in which is recorded in accordance with the DSC (English, Document Structuring Conventions) standard, but with a number of extensions that allow this format to be used as a graphic one.
The EPS format was created by Adobe based on the PostScript language and served as the basis for the creation of early versions of the Adobe Illustrator format.
In its minimal configuration, an EPS file has a so-called BoundingBox DSC comment - information describing the size of the image. This way, even if the application cannot rasterize the data contained in the file, it has access to the image dimensions and its preview.
QuarkXPress versions 4, 5 and 6 cannot rasterize data from an EPS file, so it uses only a preview in the layout - a small copy of the entire image, which is stored in the EPS file separately from the main data. Adobe InDesign versions CS-CS4 do not have such a limitation. The use of a reduced-quality copy of the image is intended to simplify the display of the image on the screen and, as a result, significantly speed up the work with layout. Preview can be recorded in TIFF or WMF format (PC only) or omitted altogether.
The format is used in professional printing and can contain raster images, vector images, and combinations thereof.
An image recorded in EPS format can be saved in different color spaces: Grayscale, RGB, CMYK, Lab, Multi-channel.
The data structure of an EPS raster file can be written using different methods: ASCII data (text data), Binary data (binary data) and JPEG with different compression rates.
2) WMF (English: Windows MetaFile) - a universal format of vector graphic files for Windows applications. Used to store a collection of Microsoft Clip Gallery graphics. The format was developed by Microsoft and is an integral part of Windows, as it preserves a sequence of hardware-independent GDI (Graphical Device Interface) functions that directly output an image to a given graphics device context (to the screen, to a printer, etc.). Very often, WMF is used implicitly to save an image of a program's output window and restore it later, as well as when transferring information via the clipboard. From MS Windows, writing and reading a file of this format is extremely simple and fast; in other operating systems, support for this format is useless. Some Macintosh programs understand it. On the Macintosh platform, the PICT format plays a similar role.
3) CDR file format - a vector image or drawing created using the CorelDRAW program. This file format was developed by Corel for use in its own software products. CDR files are not supported by many image editing programs. However, the file can be exported using CorelDRAW to other, more common and popular image formats.
Also, CDR file can be opened with Corel Paint Shop Pro. For best compatibility, Corel recommends saving files in CorelDRAW CDR format version 9.0 or earlier.
4) Portable Document Format (PDF) is a cross-platform electronic document format created by Adobe Systems using a number of PostScript language features. Primarily intended for presentation in in electronic format printing products - a significant amount of modern professional printing equipment can process PDF directly. You can use the official free program to view Adobe Reader, as well as third-party programs. The traditional way of creating PDF documents is a virtual printer, that is, the document as such is prepared in its own specialized program - a graphics program or text editor, CAD, etc., and then exported to PDF format for electronic distribution, transfer to a printing house and etc.
Complex format
There are also complex formats that can store both vector and raster information. These are the formats DjVu, CGM, AI (format of the Adobe Illustrator program), EPS (Encapsulated PostScript - a professional universal vector-raster format used by all professional graphic programs) and PDF (Portable Document Format - format of the Adobe Acrobat program, which can contain raster and vector graphics and text information).
1) DjVu (from the French déjà vu - “already seen”) - a lossy image compression technology designed specifically for storing scanned documents - books, magazines, manuscripts, etc., where the abundance of formulas, diagrams, drawings and handwritten symbols makes it extremely labor-intensive their full recognition. It is also an effective solution if it is necessary to convey all the nuances of design, for example, of historical documents, where not only the content is important, but also the color and texture of the paper; parchment defects: cracks, marks from folding; corrections, blots, fingerprints; traces left by other objects, etc.
DjVu has become the basis for several libraries of scientific books. A huge number of books in this format are available on file-sharing networks.
The format is optimized for network transmission so that the page can be viewed before the download is complete. A DjVu file can contain a text (OCR) layer, which allows full-text search of the file. In addition, a DjVu file can contain a built-in interactive table of contents and active areas - links, which allows for convenient navigation in DjVu books.
2) CGM (from the English Computer Graphics Metafile) - a format for storing and exchanging graphic data that is not related to CAD.
3 Dpolygons
The X file format is a file format for storing 3D objects created by Microsoft.
This format stores information about the geometry of a 3D object (vertex coordinates and normal coordinates), texture coordinates, description of materials, paths and names of textures that are used. The hierarchy of objects is stored, the animation is stored, and the bindings of vertices to “bones” with a description of the weights are stored. The X file may not contain any information about the object (for example, the X file may only contain vertex coordinates).
An X file can be text or binary.
At the beginning of the X file there is a header, then there is a description of information about the object. The description of information can be in any order, but the title always comes at the very beginning.
CONCLUSION
No other computer application can boast such a variety of file format types as computer graphics. Every more or less reputable software company considers it their duty to create at least some kind of graphic editor, and in addition to it, of course, they create their own own format files in which, as the developers assure, this editor saves masterpieces created with its help, the best way. As a result of this approach, a situation has arisen where no one is able to cover all the variety of types of existing graphic formats. Graphic files are quite complicated, unlike, say, a simple text file. Over time, the need arose to obtain graphic files with certain requirements. For example, a computer artist needs very high quality pictures, for the average user - good quality, but not a very large volume; a web designer needs to get a more or less decent image with a minimum volume. But the requirements for file portability between different applications forced the identification of several specific formats, which have become, each in their own area, de facto standards. So, for images on the Internet, in most cases, they use JPEG formats and GIF, for storing images - JPEG, in publishing TIFF reigns, etc.
This is not to say that there are bad formats and there are good ones. Each format has advantages and disadvantages. This article will talk about only some of the graphic formats that are supported by most graphics programs and are used in practice more often than others.
Raster images are saved in a file in the form of a rectangular table, in each cell of which the binary color code of the corresponding pixel is written. Such a file stores data about other properties of the graphic image, as well as its compression algorithm.
Vector images are saved in a file as a list of objects and the values of their properties - coordinates, sizes, colors, etc.
There are quite a large number of both raster and vector graphic file formats. Among this variety of formats, there is no ideal one that would satisfy all possible requirements. The choice of one or another format for saving an image depends on the goals and objectives of working with the image. If photographic accuracy of color reproduction is needed, then preference is given to one of the raster formats. It is advisable to store logos, diagrams, and design elements in vector formats. The file format affects the amount of memory the file occupies. Graphic editor allow the user to independently choose the format for saving the image. If you are going to work with a graphic image in only one editor, it is advisable to choose the format that the editor offers by default. If the data will be processed by other programs, it is worth using one of the universal formats.
There are universal graphics file formats that simultaneously support both vector and raster images.
Bibliography
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