What formats are graphic images. What formats of graphic files (image formats) are there and in what programs they can be opened

Each of us, one way or another, is faced with images. Let's look at the issue of understanding this term a little more broadly. After all, image formats include not only graphics, animation, animation, etc.), but also video. We will separately dwell on the issues of file conversion, as well as storage of this or that type of information.

What are image formats?

This is information stored in a file that is intended for data visualization (displaying it on a reproducing device such as a monitor, TV, printer, mobile device, etc.).

As for the information in the file itself, for the most part it describes the rendering method, the method of creating a solid static or dynamic image, its size (not to be confused with the size of the file itself), the number and depth of colors and their shades, and so on.

Concept of vector and bitmap graphics

First, let's consider what image formats are used exclusively in the standard understanding of graphics. It is necessary to clearly distinguish between vector and raster graphics. These two types are basic.

Vector graphics allow visualization of an object based on a mathematical description of the set of aggregate elements that make up the image, which are usually called primitives. These include the simplest concepts familiar to everyone from school. These are points, lines, curves, circles, polygons, etc.

The advantage of this approach is the ability to describe in an arbitrarily large number of individual elements without significantly increasing the final file size. In addition, scalability is very strongly manifested here, which allows you to resize each individual element or their entire collection without losing the quality of the entire image. Such a descriptive algorithm is mainly suitable for graphics created by hand, for example, in some kind of graphics editor. This method is not applicable for photographs.

PCX is a format for storing bitmap images with a color depth of 24 bits. Compression is very fast, but not suitable for converting detailed graphics such as photographs.

RAW is a versatile format used for images taken directly from digital cameras. We can say about it that this is the format of the best image quality. It can serve as a source material for processing not only images, but also sound. In addition, the support for metadata provides tremendous potential for processing and applying lossless or lossy compression algorithms of any level. The format is quite specific and requires certain knowledge when working with it.

File formats of specialized graphics editors

In addition to the standard types, it is possible to separately highlight the formats of graphic images used in specialized editors.

PDF is a format that can contain text and graphic data. Developed by Adobe Corporation. This format assumes the use of different compression methods for each specific element contained in the final file. Today it is universal mainly for technical documentation in electronic form.

CDR is a vector format of the graphics editor Corel Draw. It can only be processed with such a software package. Not supported by other editors, but easily exported to other formats.

AI is an Adobe Illustrator format supported by most other editors. The main feature is the highest image stability and full compatibility with PostScript technology. It can be used as an intermediate format when translating from one to another.

PSD is the best image format in Adobe Photoshop for intermediate editing of complex images. Allows layers and blending modes, but is larger than other formats. As the final format for saving files, it is used exclusively in the program itself.

Large format images

If we talk about a large format, where you need to take into account high detail, then you should use RAW, TIFF or PSD.

However, many professional photo and video cameras with matrices of 20-25 megapixels have their own standards. Most of them are adapted to the most common types of formats. It all depends on the settings of the camera itself. The same goes for mobile devices.

Basic types of video and animation

Now let's briefly dwell on the video, since it can also in a sense be interpreted as an image, or rather, as a set of alternating images (frames). Here, the determining factor is the frame rate per second (fps) and the size of the picture in pixels.

Initially, at the dawn of the development of digital video, it was the well-known AVI format, which is still used today, since it is a kind of container containing information processed or compressed by completely different methods (codecs). A special decoder is required for playback.

A little later, such well-known formats as WMV, MPG, MKV, MP4, VOB, TS and many others appeared, and the latter can even be considered as high-definition TV picture formats that allow you to play files with HD, Full HD (2k) or Ultra quality standards. HD (4k).

When it comes to animation, Flash is the most well-known technology today. Initially, it was a development of the Macromedia corporation, but then it was bought by Adobe and significantly modernized. The format of these files is SWF. It is mainly used to create small animation videos, computer animation, banners or for simple games.

Mobile systems

If we talk about mobile systems (smartphones or tablets based on Android, iOS, Blackberry, etc.), then specialized image formats are extremely rare. Mostly standard computer image formats are used for both graphics and video. However, without installed codecs and decoders, some types of video will not play. That is why you will have to solve the problem of converting the source material to another type.

For example, regular phones only accept 3GP format. Android or iOS recommend using MP4. But in general, there are enough options.

Changing the basic parameters of images

Probably everyone understands perfectly well that editing needs to be done using special programs.

The simplest operations for resizing, reflecting, rotating, tilting and others can be performed even in the most primitive Paint editor, which is included with any Windows operating system.

If more complex actions are required, for example, changing color, saturation, contrast, editing layers, splitting an image into separate components, etc., then you will have to use professional packages like the aforementioned Corel Draw or Adobe Photoshop.

There are utilities for video editing, for example, Vegas Pro. In addition to standard features, they can use specialized effects and modeling systems that allow transferring a real image to a pre-built mathematical model, similar to how the battle between Morpheus and Neo was filmed in the first part of the "Matrix".

Format conversion

Conversion (converting) is performed using utilities called converters. One of the most prominent representatives is Xilisoft Video Converter, which can convert both graphics and video.

For graphics, you might prefer, for example, ACDSee Ashampoo Photo Commander, Free Image Convert And Resize, or something else. Today you can find a lot of such programs.

The only thing to look out for is the final format and the possible loss of quality (image compression formats). When viewing a picture or video on a smartphone or tablet, it will not be so noticeable, but on the TV panel, the difference will become very noticeable.

What is the preferred format for storing data?

Photos on your computer can be stored in the universal JPG format. When viewing them on a monitor, special clarity is not needed. It's another matter when photographs need to be printed. It is better to use original camera formats here.

When converting one format to another, it will sometimes be simply impossible to restore the "source", so when submitting files to the studio, it is not recommended to change their initial appearance. An exception if you have the necessary knowledge and edit yourself using professional software.

The same goes for videos. It all depends on what device it will be viewed on.

Conclusion

There are many and varied image formats, including graphics and video. The article reviewed the most popular formats. The questions of their processing and transformation, the choice of software, the format used for storing data, etc., each user decides for himself.

In which any types of persistent graphic data ("images") are stored, intended for subsequent visualization. The way these files are organized are called graphic formats. After being written to a file, the image ceases to be an actual image - 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 supported graphics, file formats are classified into one of the following types: raster format, vector format, metafile format. The most common graphic formats are:

AI (Adobe Illustrator, Adobe AI) - metafile format developed by Adobe for Macintosh, Microsoft Windows, NeXT; is used to record and store various types of images, including drawings, drawings and decorative inscriptions.

PSD (Photoshop Document, Adobe Photoshop, Adobe PSD) - a raster format included in the Adobe graphics editor Photoshop; 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, outlines and other graphic elements.

ART is a format developed by Gonson-Grace 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 every version of AutoCAD. DXF and DXB file names use the extensions * .dxf, * .dxb, * .sld, * .adi.

BDF (Bitmap Distribution Format) is a bitmap format developed by the X Consortium for exchanging bitmap font data between X Window and other systems. There is no compression, the maximum image size is not limited, the color is monochrome. Each BDF file stores data for only one typeface (a group of fonts united by a single name).

BMP is a bitmap format developed by Microsoft for Windows; supported by all graphic editors working under its control, it is capable of storing both indexed (up to 256 colors) and RGB-color (16, 7 million shades). Most BMP files are stored uncompressed.

CDR (CorelDRAW Document) is a vector format originally known for low stability and poor file compatibility. Many PC programs (FreeHand, Illustrator, PageMaker) can import CDR files. Starting with the seventh version of CorelDRAW in CDR files, compression is applied separately for vector and bitmap 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, computer publishing systems. Although CGM contains many graphics primitives and attributes, it is less complex than PostScript, allows for more compact files, and supports the exchange of high quality complex and 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 that provides storage of full-color images and vector objects.

DPX (Digital Picture Exchange Format; aka SMPTE Digital Picture Exchange Format) is a raster format designed to store one film frame or video stream; Developed by Kodak Cineon and adopted by ANSI and the Society of Motion Picture and Television Engineers (SMPTE) with minor changes to the standard. The format is supported by programs from Kodak.

DWG is a vector format of Autodesk's AutoCAD program designed for storing drawings.

EMF (Enchanced Metafile) is a metafile format developed by Microsoft for storing images in the form of a sequence of commands that lead to the playback of images. In November 2005, the vulnerability of EMF and WMF formats from "buffer overflow attacks" was discovered, and at the end of December - the emergence of a family of Internet worms. 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 that spread in the form of mail worms appeared in attached image files. Microsoft has responded to this threat by issuing Security Advisory 912840, as well as (January 11, 2005) patching Windows 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 provides optimal distribution of resources on the PC platform, supports all colors without limitation, 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 * .3ds extension and text with * .asc extension.

EPS (Encapsulated PostScript, EPSF) is a simplified version of the PostScript format (PDL), developed by Adobe as a vector format, later its raster version - Photoshop EPS - appeared. EPS format cannot contain more than one page per file and does not store a number of printer settings. As with PostScript print files, EPS records the final work, although programs such as Adobe Illustrator, Photoshop, and Macromedia FreeHand can use it as a work tool.

FH8 (FreeHand Document) - the eighth version of the FH format, intended only for Macintosh PCs. FreeHand itself, Illustrator 7 and a limited number of Macromedia programs can work with it. Since the seventh version, the FH format has full cross-platform compatibility, however, some FreeHand effects are not PostScript compatible.

FIF (Fractal Image Format) - a format developed by Iterated Systems, used for storing photographs and on the Internet, 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 (received by orbiters) and ground images (in particular, radio astronomy data and digitized photographic images) ... The format is widely used to exchange data between various hardware platforms and software applications that do not support the common file format. FITS is considered a fairly straightforward, uncompressed format with "unlimited" 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 bitmap format for representing images on the WWW; was developed in 1987 by CompuServe, overshadowed 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 compress files well with many homogeneous fills (logos, inscriptions, schemes), record the image "through a line" (Interlaced mode), due to which, having only a part of the file, you can see the whole image, but with a lower resolution (GIF supports resolution up to 66536x65536).

IFF (Interchange File Format), ILM, ILBM, LBM (InterLeaved BitMap), Amiga Paint is a family of raster formats developed and supported for 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 the Amiga. IFF was previously known as the 24-bit format for MS-DOS, but later it began to be replaced by TIFF and TGA, and then by JFIF. Some of the characteristics of the IFF format: maximum image size 64K by 64K pixels; used in uncompressed and RLE compression versions, supports 1 to 24-bit colors; format of numbers "senior in minor", has a specification on CD; when used with MS-DOS and UNIX, filenames can have * .iff and * .lbm extensions.

JFIF (JPEG File Interchange Format), JFI, JPG, JPEG is the raster format from C-Cube Microsystems that is the most widely used, so most of the "JPEG" images would be more correctly called "JFIF". With 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 bitmap formats; intended for storing illustrations in desktop publishing systems. The format was developed by Zsoft for the Paintbrush program, after an OEM agreement with Microsoft, it began to be used in various systems that work with graphics. Main characteristics: maximum image size 64K by 64K; 24-bit color support; uses RLE compression (can work without compression); supports work with CD-ROM. The versions of the PCX format are DCX and PCC, whose filenames have a corresponding extension.

PDF (Portable Document Format) is a metafile format proposed by Adobe for graphic files (vector and raster) containing illustrations and text with a wide range of fonts and hypertext links in order to transmit them over the network in a compressed form.

PDS (Planetary Data System Format) is a NASA standard format for storing data collected by spacecraft and ground-based observations of the Sun, Moon and planets; is also used by other organizations to store similar data. The format is based on the object description language - ODL (Object Description Language). The maximum image size and colors in PDS format are unlimited; supported by all platforms.

PGML (Precision Graphics Mark-up Language) is a vector format that describes graphics in terms of mathematical formulas, not raster pixels, thereby saving disk space and the ability to scale an image without losing its resolution and other quality indicators. The format was submitted for consideration to the W3C (WWW Consortium) as a network standard by Adobe Systems, IBM, Netscape, Sun Macromedia; used on the Internet.

Photo-CD (PCD, Kodak Photo CD) is a raster format developed by Eastman Kodak for storing and reproducing full color images (usually still photographs) recorded at various resolutions on compact discs. The format is supported by Photo CD ACCess, Photoshop, Shoebjx. The Photo CD format supports 24-bit colors, has its own compression system, the maximum image size is 2048x3072 pixels, allows only one image to be stored in a file, uses the RLE and JPEG compression systems (in the DCT version). Kodak does not disclose further details.

PIC (Pictor PC Paint, PC Paint) is a bitmap format developed by Paul Mace for painting programs on the MS-DOS platform. It is a hardware-dependent format created taking into account the requirements of the IBM graphics adapters (CGA, EGA, VGA). The PIC format is similar to the PCX format, the filenames use the * .pic and * .clp extensions.

PICT (Macintosh QuickDraw Picture Format) is a clipboard standard for Macintosh PCs that supports both raster and vector graphics. On a Macintosh PC, the PICT works with all programs. On a PC, it is 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 is intended to replace GIF. The format provides indexing up to 256 colors, support for 24-bit and 48-bit color representation (True Color) and the implementation of a transparency channel (the so-called alpha channel). The PNG lossless dynamic compression algorithm is 10-30% more efficient than the similar type of compression implemented in the GIF format.

PS (PostScript) is a PostScript page description language (also known as a laser printer control language) developed in 1984 by Adobe. The format is used to provide printing and storage of fonts, as well as for the exchange of documents formatted by it. The advantage of the PS format is that it uses a device-independent display system (including the type of printer or screen).

RAF (RAW) is a raster format used in digital cameras that supports the image directly as it was captured by the camera sensor. The use of this format eliminates artifacts associated with the preprocessing of the image by the camera software (for example, when it is JPEG-compressed) and provides the photographer with the possibility of post-processing of photographs (adjusting the exposure, changing the color balance, increasing the size).

Scitex CT is a raster format developed by Scitex; slightly differs from TIFF, with the exception of one peculiarity: on the Scitex Dolev phototypesetters (Imagesetters), files of this format are output somewhat faster. On PC, Scitex CT file names have the * .sct extension.

SWF (Shockwave Flash) is an internal vector format of Macromedia's Flash program used for animation on the Internet.

TGA (TrueVision Targa) is Truevision's color TV format that supports RLE compression and has a * .tga filename extension.

TIFF (TIF, Tagged Image File Format) is a bitmap format developed by Aldus Corporation, originally intended for large high-resolution graphics obtained by scanning. The format is characterized by high quality transmission and color preservation of the original images. Later 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 to transfer vectors through the clipboard. WMF is supported by almost all programs running under Windows and related to vector graphics in one way or another. Despite the seeming simplicity and versatility, it is recommended to use the WMF format only in extreme cases for transferring the so-called bare vectors. WMF distorts color, does not preserve a number of parameters that can be assigned to objects in various vector editors, is not understood by programs targeting Macintosh PCs. 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.

It was last Friday, but we couldn't write the Friday post for N3. The reason is trivial - lack of free time in connection with the housing issue and a number of other problems. But, this Friday the photo will be for sure. It is already there and was ready for publication yesterday, but nevertheless I decided to spend my free evening time on repair work in the apartment. Therefore, if you have not looked, then be sure to look and - cheer yourself up.

Let's return to the topic of the post, or rather to the question of what picture formats are there? Generally the word "picture" in relation to photography, I do not like it. But this is how this question sounds very often, so I decided to leave everything unchanged. I will only make one clarification. Since a photo is a raster image, then the post will only talk about bitmap graphic image formats.

Generally graphic formats- a set of rules for processing the received graphic data, for the purpose of their further storage or editing. As V. Mayakovsky's lines say, “All professions are needed, all professions are important” ... The same can be attributed to image formats.

Developers offer a lot raster formats for storing files. Among the most commonly 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 the listed raster image formats.

Bitmap formats

• BMP -(abbreviation for Bit Map image) represents standard bitmap format and has a universal purpose. It is supported by most graphics editors, including the fairly common one Paint... Initially, coding was carried out in the simplest way, using. 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 transfer images. In the future, he improved somewhat. Bit Map image almost ideal for storing and exchanging data with other 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 interlaced display.
• Tiff— (from Taged Image File Format)- universal for publishing systems and topographic graphics. Such bitmap formats provide high quality printing. They were created to support almost all programs designed to work with bitmap files, therefore they are compatible with all platforms. Widely used Tiff in printing and publishing. Files (scanned images, illustrations, faxes, etc.) with the extension .tif in this powerful format is stored for further color printing, although monochrome printouts are available - in representations CMYK and RGB... It is not used for publishing pictures on a computer network or when creating websites, because it has a fairly significant size. It is also unsuitable for animation.
• GIF— (initials from Graphic Interchamge Format)serves for storagebitmaps in graphicsand to exchange them. It is one of the "oldest" on the Internet, has been in circulation for a long time, despite the fact that it uses indexed colors (in a limited set). Files with extension.gifwidely used in the construction of web sites. Among the main advantagesGraphic Interchamge Format it is worth mentioning that the appearance of the picture does not depend on the underlying platform or on the type of browser, and the compression occurs without loss of information. Pictures with a small amount of uniform colors, drawings, transparent pictures and animation are displayed in high quality in this format.GIFsmall in size, so it loads quickly, which is important when creating HTML pages. But still, the format has a significant drawback - it has an insignificant set of colors, which limits its possibilities when storing images with smooth transitions.
• Jpeg— (abbreviation for Joint Photographic Expert Group) helps to get rid of the flaws that arise when creating and saving images in GIF. It uses a compression method for photographs or other images. These raster graphic file formats are most common when storing multi-color pictures. Compress images (they are stored in files marked .jpg). is executed in a smooth mode, which ensures a high degree of it and reduces data loss. On the hard disk in Jpeg it is convenient to save a significant number of pictures, in particular - large photographs with smooth transitions. This can significantly save disk space. Also using Jpeg it is available to publish a photo of quite acceptable quality on a computer network. But it should be borne in mind that during compression, part of the data is lost, and when the same image is saved again, the chances of irreversible loss of information increase. In this regard, the situation is much improved by the improved version of the format - JPEG 2000... True, it is not supported by all browsers, which slows down its distribution.
• PNG image— (portable network graphics) allows you to store raster graphics in a lossless compressed form, and the files are smaller in size than GIFs. In the format PNG image use of almost any color is available, as well as transparency. This circumstance opens up wide possibilities in web design. Now it enjoys constant popularity, since it fits with all platforms, supports interlaced display, has a significant color gamut, and supports animation.
• Internal raster graphics formats psd (short for PhotoShop Document) are for program packages. They support all types of images, as well as their layers during processing. Saved in files marked with the extension .psd.

There are others raster graphics formats, which were not discussed in the article, but you can write about them in the comments, while not forgetting about the competition!

Brief annotation: Graphic data compression methods. Saving images in standard formats, as well as proprietary formats of graphics programs. Convert files from one format to another.

Target: know the methods of compressing graphic files, be able to distinguish between graphic file formats and understand the appropriateness of their use when working with various graphic programs.

An image is characterized by the maximum number of colors that can be used in it, that is, have different depth of color... There are types of images with different color depths - black and white line, grayscale, indexed color, full color. Some types of images have the same color depth, but differ in color model. The image type is determined when the document is created.

Halftone images.

These images contain pixels of the same color but different brightness. Each pixel can take 256 different brightness values ​​from 0 (black) to 255 (white). This is enough to correctly display an image, for example, a black and white photograph.

Any image can be converted to grayscale. If the source material is, for example, a color photograph, then it will become monochrome.

Rice. 1.7.

Indexed Color Images

Indexed colors are called so because in this mode, each pixel in the image is assigned an index that points to a specific color from a special table called a color palette. Indexed palettes do not contain more than 256 colors, but there can be much less. The fewer colors in the palette, the less memory is required to store the color of each pixel and, therefore, the smaller the image file size.

Full color images

Full color images have no color limit and can be represented in over 16 million shades.

Graphics file formats

Format- the structure of the file, which determines how it is stored and displayed on the screen or when printing. The file format is usually indicated in its name, as a part separated by a period (usually this part is called the file name extension).

Extension is a series of letters or numbers that appear after a period in the file name.

For example, the name ending (extension) ".txt" is usually used to denote files containing only text information, and ".doc" - containing text information structured in accordance with the Microsoft Word program standards. Files with content that conform to the same format are referred to as files of the same type.

Graphic file formats determine how information is stored in a file (raster, vector), as well as the form of information storage (compression algorithm used).

Compression is used for bitmap graphic files, because they have a fairly large volume.

Table 1 summarizes the commonly used image file formats.

Graphic file formats. BMP, TIFF, JPEG, GIF, PNG and other formats. Characteristics and application of various formats. Methods for presenting graphical information within a file. Converting formats.

Graphics file formats

Computer graphics use at least three dozen file formats for storing images. But only some of them are used in the vast majority of programs. As a rule, files of raster, vector, three-dimensional images have incompatible formats, although there are formats that allow storing data of different classes. Many applications are focused on their own "specific" formats, transferring their files to other programs forces you to use special filters or export images to a "standard" format.

BMP (Windows Device Independent Bitmap). The BMP format is a native Windows format, it is supported by all graphics editors running under its control. A huge number of programs work with the BMP format, since its support is integrated into the Windows and OS / 2 operating systems. BMP files can have the extensions .bmp, .dib, and .rle. In addition, data in this format is included in the RES binary resource files and in the PE files.

BMP format can save images with a color depth (the number of bits describing one pixel of the image) 1, 4, 8 and 24 bits, which corresponds to the maximum number of used colors 2, 16, 256 and 16,777,216. The file can contain a palette that defines the colors different from those accepted in the system.

Tiff(Tagged Image File Format). The format is intended for storing high quality raster images (filename extension is .TIF). TIFF is a hardware-independent format, it is supported by almost all programs on PC and Macintosh, one way or another related to graphics. TIFF is the best choice when importing bitmap graphics into vector programs and publishing systems. It has the full range of color models from monochrome to RGB, CMYK and Pantone complementary colors. TIFF can preserve layers, clipping paths, alpha channels, and other additional data.

TIFF comes in two flavors: for Macintosh and PC. This is because Motorola processors read and write numbers from left to right, while Intel processors do the opposite. Modern programs can use both formats without problems.

The native program for this format, Photo-Styler, is now "out of production", but the format continues to evolve and be supplemented with new features. Letraset introduced an abbreviated version of the TIFF format called RIFF (Raster Image File Format).

LZW-, JPEG-, ZIP-compression can be used in TIFF format. Some older software (eg QuarkXPress 3.x, Adobe Streamline, many text recognition software) cannot read compressed TIFF files, however if you are using newer software there is no reason not to use compression.

TIFF, despite all the compression algorithms, is still the most "multi-weight" raster format, so it is not suitable for use on the Internet.

Psd(PhotoShop Document). The native format of the Adobe Photoshop program (filename extension .PSD), one of the most powerful in terms of storage capabilities for raster graphic information. Allows you to remember the parameters of layers, channels, transparency, many masks. Supports 48-bit color coding, color separation, and various color models. The main disadvantage is expressed in the fact that the absence of an effective information compression algorithm leads to a large volume of files. Not all programs open.

PCX... The format originated as a storage format for bitmap data in the PC PaintBrush program by Z – Soft and is one of the most common (filename extension .PCX). The inability to store color-separated images, the lack of color models and other restrictions have led to the loss of popularity of the format. Currently considered obsolete.

JPEG (Joint Photographic Experts Group). The format is intended for storing raster images (filename extension .JPG). Allows you to adjust the ratio between the file compression rate and image quality. The applied compression methods are based on the removal of "redundant" information; therefore, the format is recommended to be used only for electronic publications.

The JPEG file format was developed by C – Cube Microsystems as an efficient method for storing deep color images, such as those produced by scanning photographs with many subtle shades of color. The biggest difference between JPEG and other formats is that JPEG uses a lossy compression algorithm. A lossless compression algorithm stores information about the image in such a way that the decompressed image exactly matches the original. Lossy compression sacrifices some of the image information in order to achieve a higher compression ratio. A decompressed JPEG image rarely matches the original exactly, but very often the differences are so subtle that they are barely detectable.

JPEG is a compression algorithm based not on finding the same elements, as in RLE and LZW, but on the difference between pixels. Data encoding takes place in several stages. First, the graphic data is converted to a LAB color space, then half or three quarters of the color information is discarded (depending on the implementation of the algorithm). Next, blocks of 8x8 pixels are analyzed. A set of numbers is formed for each block. The first few numbers represent the color of the block as a whole, while the subsequent numbers represent the subtle ones. The spectrum of detail is based on human visual perception, so large details are more visible.

In the next step, depending on the quality level you choose, a certain portion of the numbers representing subtle details are discarded. The last stage uses Huffman coding to compress the final data more efficiently. Data recovery is performed in reverse order.

Thus, 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! The format is hardware independent, fully supported on PC and Macintosh, however, it is relatively new and not understood by old programs (until 1995). JPEG does not support indexed color pickers. Initially, CMYK was not included in the format specifications, Adobe added support for color separation, but CMYK JPEG makes problems in many programs. The best solution is to use JPEG compression in Photoshop EPS files, which is described below.

There are JPEG sub-formats. Baseline Optimized - files are slightly better compressed, but not readable by some programs. JPEG Baseline Optimized is designed specifically for the web and is supported by all major browsers. Progressive JPEG is also designed specifically for the Web, its files are smaller than standard ones, but slightly more Baseline Optimized. The main feature of Progressive JPEG is its support for interlaced analog output.

From what has been said, the following conclusions can be drawn. JPEG compresses photo-quality bitmap images better than logos or schemes - they have more grayscale transitions, and unwanted noise appears among monophonic fills. Large images for the web or with a high print resolution (200-300 and fighter dpi) are compressed better and with less loss than with a low one (72-150 dpi). in each square of 8x8 pixels, the transitions are softer, due to the fact that there are more of them (squares) in such files. It is undesirable to save any images with JPEG compression, where all the nuances of color rendition (reproduction) are important, since color information is discarded during compression. Only the final version of the work should be saved in JPEG, because each resave leads to all new data loss (discarding) and the transformation of the original image into a mess.

GIF (GraphicsInterchangeFormat). The hardware agnostic GIF format was developed in 1987 (GIF87a) by CompuServe for transferring bitmap images over networks. In 1989, the format was modified (GIF89a), and support for transparency and animation was added. GIF uses LZW compression, which allows you to compress files with a lot of homogeneous fills (logos, labels, schemes) quite well.

GIF allows you to record an image "through a line" (Interlaced), due to which, having only a part of the file, you can see the whole image, but at a lower resolution. This is achieved by writing and then loading, first 1, 5, 10, etc. lines of pixels and stretching the data between them, the second pass is followed by 2, 6, 11 lines, the image resolution in the Internet browser increases. Thus, long before the end of the download of the file, the user can understand what is inside and decide whether to wait for the entire file to be uploaded. Interlaced writing slightly increases the file size, but this is usually justified by the acquired property.

In GIF, you can set one or more colors to be transparent, they will become invisible in Internet browsers and some other programs. Transparency is provided by an additional Alpha channel saved with the file. In addition, a GIF file may contain not one, but several raster images that browsers can load one after another with the frequency specified in the file. This is how the illusion of movement is achieved (GIF animation).

The relevance of the concepts implemented in the GIF format has become especially evident in connection with the increased use of electronic publications (in the form of Web pages or Web sites). Despite the ever-increasing bandwidth of network hardware, and, in particular, modems, the issue of the volume of graphic elements of electronic publications is quite acute. On the one hand, the visibility and efficiency of an electronic publication largely depends on the quality of the graphic elements, and, first of all, on the resolution and color depth of the image pixels. Therefore, the desire of the developers of electronic publications to use multicolor graphic images is understandable.

On the other hand, the requirements for the compactness of files transmitted over network channels did not recede into the background. Large graphic files take a long time to load the image into the browser. Therefore, one of the main tasks of professionals in the field of Web-design is precisely to find the proper balance between the artistry, information content of a Web page and its volume.

GIF is one of the few formats that uses an efficient compression algorithm that is almost as good as archiving programs. In other words, GIFs do not need to be archived, as this rarely gives a tangible gain in volume.

Therefore, the GIF format, the main advantage of which is the minimum file size, still retains its value as the main graphic format of the World Wide Web.

The main limitation of the GIF format is that a color image can only be recorded in 256 colors. This is clearly not enough for the printing industry.

There are two GIF specifications. The first relates to the GIF87a format, which provides for recording multiple images, and GIF89a, which focuses on storing both text and graphic data in a single file.

GIF87 a provided the following GIF file features:

Interlacing. At first, only the "skeleton" of the image is loaded, then, as it is loaded, it is detailed. This allows not to load the entire graphic file on slow lines in order to get an idea of ​​it.

Compression (compression) according to the LZW algorithm. This trait of GIFs keeps them in the lead for the smallest file size.

Placing multiple images in one file.

The location of the image on the logical screen. That is, the format made it possible to define a logical screen area for displaying images, and place them in an arbitrary place in this area.

Later, this standard was extended by the GIF89a specification, which added the following features:

Inclusion of comments in the graphic file (not displayed on the screen, but can be read by a program that supports GIF89a).

Delay control before changing frames (set in 1/100 second, or waiting for user input).

Controls the deletion of the previous image. The previous image can be retained, replaced with the background color, or whatever was in front of it.

Determination of a transparent color.

Text output.

Creation of control blocks by application-specific extensions. Inside a GIF file, you can create a block that will be ignored by all programs except the one for which it is intended.

PNG image (PortableNetworkGraphics). PNG is a relatively recently developed format for the Web, designed to replace the outdated GIF. Uses lossless compression Deflate, similar to LZW (it was because of the patenting in 1995 of the LZW algorithm that PNG was born). Compressed indexed PNG files are generally smaller than their equivalent GIFs, and RGB PNGs are smaller than their corresponding TIFF file.

PNG files can have any color depth, up to 48 bits. Two-dimensional interlacing is used (not only rows, but also columns), which, just like in GIF "e, slightly increases the file size. Unlike GIF, where transparency is either present or not, PNG also supports translucent pixels (i.e. is in the transparency range from 0 to 99%) due to the Alpha channel with 256 grayscale.

The gamma correction information is written to the PNG file. Gamma is a certain number that characterizes the dependence of the brightness of the glow of your monitor screen on the voltage at the kinescope electrodes. This number, read from the file, allows the display brightness to be corrected. It is needed so that the picture created on Mac looks the same on both PC and Silicon Graphics. Thus, this feature helps to implement the main idea of ​​the WWW - the same display of information regardless of the user's hardware.

PNG is supported in Microsoft Internet Explorer from version 4 on Windows and from version 4.5 on Macintosh. Netscape added PNG support to its browser in versions starting with 4.0.4 for both platforms. However, there is still no support for such important format functions as fading transparency and gamma correction.

PNG and GIF89a have the following properties:

The format is organized as a data stream

Lossless compression

Allows to store indexed images with a palette of up to 256 colors

Progressive display of interlaced data

Transparent color support

Ability to store shared and restricted data

Hardware and platform independent

Benefits of PNG over GIF:

Faster progressive display of interlaced circuits

Advanced storage options for user data

PNG features not present in GIF format:

Storing full color 48-bit images

Storing 16-bit black and white images

Full Alpha Channel

Contrast pointer

CRC - a method for detecting errors in the data stream

The Standard Toolkit for Developing PNG Read and Write Applications

A standard set of test images for testing these applications

GIF features missing in PNG 1.0:

Ability to store multiple images in one file

Animation

Wmf (WindowsMetaFile). Windows operating system vector image storage format (filename extension .WMF). By definition, it is supported by all applications of this system. However, the lack of tools for working with standardized color palettes adopted in printing and other shortcomings limit its use (WMF distorts color, cannot save a number of parameters that can be assigned to objects in various vector editors).

EPS (EncapsulatedPostScript). Format for describing both vector and raster images in PostScript from Adobe, the de facto standard in the field of prepress and printing (file extension .EPS). Since the PostScript language is universal, the file can simultaneously store vector and bitmap graphics, fonts, clipping paths (masks), equipment calibration parameters, and color profiles. Vector content is displayed in the format WMF, and raster - TIFF. But the screen copy only in general terms displays the real image, which is a significant drawback. EPS. The actual image can be seen only on the output of the output device, using special viewers or after converting the file to PDF format in Acrobat Reader, Acrobat Exchange.

An image recorded in EPS format can be saved in different color spaces: Grayscale, RGB, CMYK, Lab, Multi-channel.

The Encapsulated PostScript format can be called the most reliable and versatile way to save data. It uses a simplified version of PostScript: it cannot contain more than one page in one file, does not store a number of settings for the printer. As with PostScript print files, EPS records the final work, although programs such as Adobe Illustrator and Adobe Photoshop can use it as a workspace. EPS is intended for transferring vectors and rasters to publishing systems, and is created by almost all programs that work with graphics. It only makes sense to use it when outputting to a PostScript device. EPS supports all color models necessary for printing, among them, such as Duotone, can also record data in RGB, clipping path, information and trapping and rasters, embedded fonts. In EPS format, the data is saved in the Clipboard of the Adobe program for exchange with each other.

You can save a thumbnail (image header, preview) with the file. This is a low-resolution copy in PICT, TIFF, JPEG or WMF format, which is saved along with the EPS file and allows you to see what is inside, since only Photoshop and Illustrator can open the file for editing. Everyone else will import the sketch, replacing it with the original information when printed on a PostScript printer. On a non-PostScript printer, the sketch itself is printed. If you are using Photoshop for Mac, save your thumbnails in JPEG format, other Mac programs save thumbnails in PICT format. These and JPEG thumbnails cannot be used by Windows applications. If you're on a PC or don't know where the file will be used, save your thumbnail in TIFF format (when given a choice).

EPS has many flavors, depending on the creator program. The most reliable EPS is created by programs produced by Adobe Systems: Photoshop, Illustrator, InDesign. Since 1996, Adobe programs have a built-in PostScript interpreter so they can open EPS and edit them. Other graphic editors cannot open EPS; moreover, the EPS files they create sometimes turn out to be, to put it mildly, special. Among the most problematic are Quark EPS, created by Save Page As EPS, and FreeHand editable EPS, created by Save As. Do not particularly trust Corel's EPS version 6 and below and EPS from CorelXARA. EPS files from CorelDraw 7 and above still have the problem of adding margins to the Bounding Box (a conditional rectangle in PostScript that describes all objects on the page). Before exporting from CorelDRAW, CorelXARA and, to a lesser extent, FreeHand "and EPS files, it is worth converting many program effects (semitransparent fills, for example) into bitmap or simple vector objects. Thick paths (more than 2 pt) may have It makes sense to also convert to objects when the program provides such an opportunity. You can check the EPS file in Adobe Illustrator, if it opens, then everything is in order.

PDF (PortableDocumentFormat). A document description format developed by Adobe (filename extension .PDF). While this format is primarily intended for storing an entire document, its impressive capabilities make it possible to efficiently represent images. The format is device-independent, therefore, images can be displayed on any device - from a monitor screen to a photographic exposure device. A powerful compression algorithm with controls for the final image resolution ensures compact files with high-quality illustrations. Almost any document or scanned image can be converted to this format. However, in order to do this, in most cases the complete Adobe Acrobat package is required, containing Adobe Acrobat Distiller and Adobe Acrobat Writer.

PDF is an open standard ISO 32000 since July 1, 2008. The PDF format allows you to embed the necessary fonts (line-by-line text), vector and bitmap images, shapes and multimedia inserts. Supports RGB, CMYK, Grayscale, Lab, Duotone, Bitmap, several types of bitmap compression. Has its own technical formats for printing: PDF / X-1, PDF / X-3. Includes an electronic signature mechanism to protect and verify the authenticity of documents. A large amount of related documentation is distributed in this format.

For viewing, you can use the official free Adobe Reader program, 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 or text editor, CAD, etc., and then exported to PDF format for electronic distribution, transfer to a printing house, etc. . P.

CDR (CorelDRAW Document). The CDR file format is a vector image or graphic created with CorelDRAW software. This file format was developed by Corel for use in its own software products. CDR files are not supported by many image editing software. However, the file can be exported using CorelDRAW to other, more common and popular image formats. Alternatively, the CDR file can be opened with Corel Paint Shop Pro.

The format has been known in the past for its low stability and poor file compatibility, but CorelDRAW is extremely convenient to use. The files of these versions use separate compression for vector and raster images, fonts can be embedded, CDR files have a huge working area of ​​45x45 meters, multipage is supported.

Ai (AdobeIllustraror). A vector image file created in Adobe Illustrator; instead of raster data, consists of paths or lines connected by points; can include objects, color and text. Ai documents can be opened in Photoshop, but the image will be "rasterized", which means it will be converted from a vector image to a bitmap. The AI ​​format encapsulates and formalizes a subset of the PostScript Page Description Language (PDL) in a structured file. These files are intended to be displayed on a PostScript printer, but can also include a bitmap version of the image, thereby providing a preview of the image. PostScript, when fully implemented, is a powerful and complex language capable of defining almost anything that can be displayed on a two-dimensional output device, and the AI ​​format has been adapted to store traditional graphics data such as drawings, drawings, and decorative writing. Note, however, that AI files can be very complex. The power of PostScript comes largely from the ability to define sequences of operations and then combine them with simple syntactic means. This hidden complexity in Adobe Illustrator files is sometimes (but not always) minimized.

Converting files

The need to convert graphic files from one format to another may arise for various reasons:

The program the user is working with does not understand the format of his file;

Data that needs to be transferred to another user must be presented in a special format.

Converting files from raster format to vector

There are two ways to convert raster to vector files:

1) converting a raster file into a raster object of a vector image;

2) tracing a bitmap to create a vector object.

The first method is used in the CorelDRAW program, which, as a rule, successfully imports files of various raster formats. For example, if a bitmap image contains 16 million colors, CorelDRAW will display an image that is close to TV quality. However, the imported raster object can get quite large even if the original file is small. Raster files store information efficiently because compression methods are often used. Vector formats do not have this ability. Therefore, a raster object stored in a vector file can be much larger than the original raster file.

The peculiarity of the second method of converting a raster image into a vector is as follows. A bitmap tracing program (such as CorelTRACE) looks for groups of pixels with the same color and then creates vector objects corresponding to them. Once traced, the vectorized drawings can be edited as desired. In fig. a bitmap is shown, which converts well to vector. The fact is that raster images that have clearly defined boundaries between groups of pixels of the same color are well translated into vector images. At the same time, the traced result of a photo-quality bitmap with complex color transitions looks worse than the original.

Original bitmap vectorized image

Original bitmap Vectorized image