Graph file formats. Raster file formats. Huffman compression method
Vector formatsVector format files are especially useful for storing linear elements (lines and polygons) as well as elements that can be decomposed into simple geometric objects (such as text). Vector files do not contain pixel values, but mathematical descriptions of image elements. Based on mathematical descriptions of graphic forms (lines, curves, splines), the visualization program constructs an image.
Vector files are structurally simpler than most raster files, and are usually organized as data streams.
Examples of the most common vector formats are AutoCAD DXF and Microsoft SYLK.
WMF. This vector format which is used graphic programs Windows OS. This format is used to transfer vector images via the clipboard to Windows environment. This format is accepted by almost all programs that work with vector graphics. This format cannot be used for raster images. Disadvantages: color distortion and failure to save a number of parameters that are set for images in graphics programs.
AI. Illustrator internal format. Can open Photoshop program and besides, this format is supported by all programs related to vector graphics. This format is the best way to transfer vector images from one program to another. Raster graphic elements are lost in most cases when transmitted via AI format.
CDR. This is an internal format of the Corel Draw program. This format is very popular, as is the software package itself. Many programs can import vector files to Corel Draw formats. The CDR format also contains raster graphic objects. This format uses compression, and different compression is applied to vector and raster files.
Metafile formats
Metafiles can store both raster and vector data. The simplest metafiles resemble vector files; they contain the language or syntax for defining vector data elements, but may also include a raster representation of the image. Metafiles are often used to transport raster and vector data between hardware platforms, as well as to move images between software platforms.The most common metafile formats are WPG, Macintosh PICT and CGM.
It was last Friday, but it was not possible to write a Friday post under N3. The reason is banal - lack of free time due to the housing issue and a number of other problems. But this Friday there will be a photo for sure. It already exists and was ready for publication yesterday, but I still decided to spend my free evening time on renovation work in the apartment. Therefore, if you haven’t watched it, be sure to watch it and cheer yourself up.
Let's return to the topic of the post, or rather to the question, what picture formats are there? In general the word "picture" I don't like it in relation to photography. But this is exactly how this question sounds very often, so I decided to leave everything unchanged. I'll just make one clarification. Just like photography is raster image, then in the post we will only talk about raster formats graphic images .
At all graphic formats— a set of rules for processing received graphic data for the purpose of their further storage or editing. As they say in the lines of V. Mayakovsky “All professions are needed, all professions are important”... The same can be said for image formats.
The developers offer a lot raster formats, intended for storing files. Among the most frequently used are the following: BMP, TIFF, GIF, JPEG, PNG, PSD, ICO.So, let's look at some of the pros and cons, as well as the scope of application of the listed raster image formats.
Raster image formats
BMP-(abbreviation for Bit Map image) represents standard raster format
and has a universal purpose. It is supported by most graphics editors, including the fairly common one Paint. Initially, coding in it was performed by the most in a simple way, By . But this turned out to be wasteful, since each pixel was represented by only one byte. Consequently, only 256 colors became available, which significantly limited the ability to transmit images. Subsequently, it was improved somewhat. Bit Map image almost optimal for storing data and sharing it with others similar applications. But, at the same time, it takes up too much memory space, since it is necessary to save the encoding of all image points. File BMP does not support animation and interlacing.
TIFF— (from Tagged Image File Format)– universal for publishing systems and topographic graphics. Such raster image formats provide high quality printing. They were created to support almost all programs designed to work with bitmap files, so they are compatible with all platforms. Widely used TIFF in printing and publishing. Files (scanned images, illustrations, faxes, etc.) with the extension .tif stored in this powerful format for later color printing, although monochrome printing is also available - in views CMYK And RGB. Does not apply to publishing images in computer network or when creating websites, because it is quite large in size. It is also unsuitable for animation.- GIF— (according to the first letters of Graphic Interchamge Format)serves for storageraster images in graphicsand for sharing them. It is one of the “oldest” on the Internet and has been in circulation for a long time, despite the fact that it uses indexed colors (in a limited set). Files with the extension.gifwidely used in the design of Web sites. Among the main advantagesGraphic Interchamge Format It is worth mentioning that the type of image does not depend on the underlying platform or the type of browser, and compression occurs without loss of information. This format displays high-quality drawings with a small amount of uniform colors, drawings, transparent pictures and animation.GIFsmall in size, so it loads quickly, which is important when creating HTML pages. But still, the format has a significant drawback - it has a small range of colors, which limits its capabilities when storing images that have smooth transitions.
JPEG— (abbreviation for Joint Photographic Expert Group) helps get rid of the flaws that arise when creating and saving images in GIFs. This uses a compression method for photographs or other images. These raster graphics file formats are the most common when storing multi-color pictures. Compressing images (they are stored in files marked .jpg) is performed in a smooth mode, which ensures a high degree of processing and reduces data loss. On the hard drive in JPEG It’s convenient to save a significant number of pictures, in particular large photographs with smooth transitions. This allows you to significantly save disk space. Also using JPEG quite accessible to publish acceptable quality photo on a computer network. But it should be taken into account that during compression some of the data is lost, and when saving the same image again, the chances of irreversible loss of information increase. In this regard, the situation is greatly improved by the improved version of the format - JPEG 2000. True, it is not supported by all browsers, which slows down its spread.
PNG— (portable network graphics) allows you to store raster graphics in a lossless compressed form, and the files are smaller in size than GIF. In format PNG Almost any color, as well as transparency, is available. This circumstance reveals ample opportunities in web design. Now it is constantly popular because it is compatible with all platforms, supports interlaced display, and has a significant color scheme, supports animation.- Domestic PSD raster graphics formats (short for PhotoShop Document) are intended for program packages. They support all types of images, as well as their layers during processing. Saved in files marked with extension .psd.
There are others raster graphics formats, which were not discussed in the article, but you can write about them in the comments, without forgetting about the competition!
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. The 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 CAD- AutoCAD programs, 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 data exchange 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). Majority BMP files stored in uncompressed form.
CDR (CorelDRAW Document) is a vector format initially known for its low stability and poor file compatibility. 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 Trojans to a 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, as well as (January 11, 2005) patching Windows XP, Windows 2000 (Service Pack 4), and 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 for data exchange between various hardware platforms and software applications, which do not support the 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 various systems that work 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 results in savings disk space and the ability 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. The format is supported by Photo 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). Kodak does not disclose further details.
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 graphics adapters IBM families (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). Dynamic image compression algorithm without Loss PNG 10-30% more efficient than this type of compression implemented in the GIF format.
PS (PostScript) - format of the PostScript page description language (also known as the control language laser printers) 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 independent specific devices 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 - 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 graphic images high resolution, 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.
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 other types of file formats computer graphics, in particular vector. Having described these formats, I will give my recommendations for their 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 the best and worst quality in accordance with the number of points (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 - dot smallest size. The image can no longer be divided. In addition, a pixel is a point 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- method of saving electronic parts, which make up a computer file. Various formats organize saving files in different ways. Consider everything existing formats I won’t do raster graphics (and I couldn’t), we’ll 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 (Taged Image File Format)- a standard format in topographic graphics and publishing systems. TIFF files provide better print quality. Because of big 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. It has an 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 of transmitted images (signatures, etc.) is also saved in the format. Image format TIFF are stored in files with the extension .tif.
GIF format (Graphic Interchamge Format) is 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 are best displayed with Not big amount uniform colors, transparent images and animation sequences (this is a very well-known feature of this graphics format). 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 by smoothly changing colors in the image. A high compression ratio is provided, the value of which reaches 100 and depends on the permissible level of loss of visual information.
The format is widely used in documents HTML and for data transmission over the network. Saves graphics settings to 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 fuzzy, blurred 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 simplest animation, 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 (a 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). A good type of 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 faster 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 websites, 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 for storage large quantities images (photos) on your hard drive, which will significantly save it working space(thanks to the 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 different compression algorithms (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 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 - a response to the transition most popular format GIF 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 photographic images up to and including 48-bit.
- 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. BMP stores color data only in the RGB model, meaning it is a format created for screen use. 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 images of the most best quality. 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 different manufacturers may differ, and it is not always possible to open them 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 Corporation 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 file compatibility different versions 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 distinguished 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 everyone Windows programs, one way or another related to vector graphics. EMF(Enhanced Metafile)
Similar to WMF.
OTHER FORMATS
SWF(ShokWaveFlash)Flash format, a product of Macromedia, which allows you to develop interactive multimedia applications. Sphere using Flash 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) World Recommended Standard Wide Web Consortium for description with using XML markup of two-dimensional vector and combined vector-raster graphics.
In the browser, SVG graphics are rendered using raster engines. Support for translucency in each layer, linear gradients, radial gradients, visual effects (shadows, hillshades, shiny surfaces, textures, patterns of any design, symbols of any complexity).
SVG is a format for two-dimensional vector graphics- as defined in the specification, but by adding a script (namely JavaScript) inside 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 the average person may generally need to create or use an icon on their website.
Many people are trying to start their own website. Even if you use ready-made template site with a style that just needs to be filled in, it would still be good 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 the 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 universal way to save 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 Low quality | JPEG |
| For printing and for the original of the best quality | RAW |
