What graphic file formats (picture formats) are there and in what programs they can be opened. The most common image formats and types of formats

The abundance of images used on computers can be divided into three large groups. First of all, 2D graphics, in which flat (without a third coordinate) images are created; this group includes raster and vector graphics. Then 3D graphics and motion graphics.

Since images are created using special tools - graphic editors - it is impossible to consider file formats without taking into account their features. First of all, what is a graphics file? In the most general case, this is the system of image information adopted in a given graphics editor and the method of saving (recording) it. Such an information system may contain both general data (representation of an image on a particular display device, size, resolution, type of printer for printing, degree and method of information compression), and data that is specific and unique. Such data is created during the image editing stage and is intended for subsequent use during editing. For example, CorelDraw files contain information about curves, Photoshop files contain information about layers, channels, etc. Each graphic editor encodes this information in a certain way when recording (saving) on a medium. Thus, the graphic file format should be understood as a set of information about the image and the method of recording it in the file. In general, all graphic formats can be divided into two groups. General-purpose formats contain only the image itself and are intended for storing, transferring or viewing images (gif, tiff, jpeg, etc.) and specific formats intended for storing intermediate results of image editing (cdr, cpt, psd, ai, etc.).

Let us dwell in more detail on the 2D group due to its greatest prevalence. A raster graphics image is an ordered array of unit elements (pixels for a monitor or dots for a printer) containing color information. The number of such elements is determined by the image size and resolution, and the file size additionally depends on the color palette used (black and white or 1-bit, grayscale and 256 colors or 8-bit, high color or 16-bit, true color or 24-bit ). Vector graphics contain mathematical descriptions of the curves and fills (areas filled with a single color and areas of gradients) that make up an image. The issue of resolution and color palette is decided immediately before the file is output to a specific physical device and taking into account its characteristics. In the printing industry, this process is known as RIP - rasterizing an image process.

File compression. Since graphic files tend to be large, the ability to compress (pack) information is useful. There are currently two known compression methods - lossless and lossy. Lossless compression algorithms are similar to those of conventional archivers (LZH, PKZIP, ARJ). The most famous of them, LZW (LZ84), is widely used in the popular raster formats GIF and TIFF. Lossy compression algorithms discard information that is not perceptible to humans (JPEG, PCD). The degree of compression in this case is much higher, but occurs more slowly and can lead to deterioration in quality (depending on the selected compression ratio). The main disadvantage of this algorithm is the impossibility of recompression without significant loss of the original image quality. Therefore, it is recommended to save only the final editing results in JPEG format, and in no case intermediate ones.

General purpose formats

Microsoft Windows Bitmap (BMP)

A format for storing raster graphics in a Microsoft Windows environment (for example, screen wallpapers and screensavers). Supports 1-, 4-, 8-, 24-bit color. Allows compression without loss of quality.

Kodak Photo CD (PCD).

Developed by Kodak. The format is intended for storing slides and negatives captured using a Kodak Photo CD type camera. Each file stores 5 copies of one image of different sizes and qualities from 192x192 to 3072x2048 pixels. It is impossible to programmatically record a PCD image on a computer; you can only import the image into a graphics editor that supports this format.

Zsoft PC PaintBrush (PCX)

One of the oldest and most famous formats for storing raster graphics. It appeared almost along with personal computers, due to which it is the most common and is supported by almost all image viewing/editing programs. Uses the simplest lossless compression algorithm RLE.

Tag Image File Format (TIFF)

Developers: Aldus and Microsoft. A universal format for storing raster graphics, widely used in publishing. It is necessary to make a reservation that there are quite a lot of its varieties, due to different compression algorithms. The format that uses the LZW algorithm has the greatest compatibility. The format supports 24 and 32-bit color (CMYK), two types of recording IBM PC and Macintosh, and can store information about masks (selected areas of the image).

TrueVision TGA (TGA)

Developed by TrueVision. The format is used for storing raster graphics and has an interesting feature - along with support for 24-bit color, it has another 8 bits for each single image element to store additional information. In particular, it may contain a mask, which is used in video editing programs, for example, to create an overlay of two sequences of frames. It has been known for a long time and is supported by many graphics packages.

Graphics Interchange Format (GIF)

Developed by CompuServe Corporation in 1987 for storing raster graphics. Implemented one of the most effective LZW compression methods for its time (87g). Allows you to display an image on the screen in four passes, allowing you to preview the image before its final drawing. In 1989, a new version of GIF 89a appeared. This format supports saving multiple images, animation sequences, and transparency colors in one file for the purpose of overlaying images on top of each other. Still widely used to store and transmit small images (page design elements) to the World Wide Web.

Joint Photographic Experts Group (JPEG)

The raster format owes its popularity to the high degree of compression of the source image, based on a lossy compression algorithm. However, this applies primarily to 24- and 8-bit images. There are several varieties, due to different compression algorithms and display methods (gradual rendering is similar to gif). Also widely used on the WWW, mainly for transmitting large images.

Specific formats

As mentioned above, this group of formats is intended mainly for “internal” use (storing intermediate results of image editing). In addition to information about the image itself, the files contain a lot of service data that cannot be correctly interpreted by other viewing/editing programs. Such data may include information about fonts, layers, selections (masks), curves, special effects, etc. The most common formats are for vector graphics - cdr (Corel Draw) and ai (Adobe Illustrator), for raster graphics - psd (Adobe Photoshop ) and cpt (Corel PhotoPaint). Typically, the final image (ie the image intended for publication) is imported into one of the general purpose formats depending on the purpose of publication (gif or jpeg for the Internet, tiff for publishing systems, etc.).

Igor Sivakov

Lecture No. 3. Graphic 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. Format conversion.

Graphic file formats

In computer graphics, at least three dozen file formats are used to store images. But only some of them are used in the vast majority of programs. As a rule, raster, vector, and three-dimensional image files have incompatible formats, although there are formats that allow you to store 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 BMR format is a native Windows format, it is supported by all graphic 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 extensions .bmp, .dib and .rle. Additionally, data in this format is included in binary RES resource files and PE files.

The BMP format can save images with a color depth (the number of bits that describe one pixel in the image) of 1, 4, 8, and 24 bits, which corresponds to a maximum number of usable colors of 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 designed for storing high-quality raster images (file name extension.TIF). TIFF is a hardware-independent format; it is supported by almost all programs on PC and Macintosh that are somehow related to graphics. TIFF is the best choice when importing raster graphics into vector programs and publishing systems. It has a full range of color models available from monochrome to RGB, CMYK and additional Pantone colors. TIFF can store layers, clipping paths, alpha channels, and other additional data.

TIFF has two varieties: for Macintosh and PC. This is because Motorola processors read and write numbers from left to right, while Intel processors read and write numbers the other way around. Modern programs can use both formats without problems.

The native program for this Photo-Styler format is currently “discontinued”, but the format continues to develop and be supplemented with new features. Letraset has introduced a shortened version of the TIFF format called RIFF (Raster Image File Format).

In the TIFF format, LZW, JPEG, and ZIP compression can be used. A number of older programs (eg QuarkXPress 3.x, Adobe Streamline, many text recognition programs) cannot read compressed TIFF files, but if you are using newer software there is no reason not to use compression.

TIFF, despite all the compression algorithms, is still the most “weighty” raster format, so it is not suitable for use on the Internet.

PSD(PhotoShop Document). Adobe Photoshop's own format (file name 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, degrees of transparency, and many masks. Supports 48-bit color encoding, color separation, and various color models. The main disadvantage is that the lack of an effective information compression algorithm leads to a large volume of files. Doesn't open in all programs.

PCX. The format appeared as a format for storing raster data in the PC PaintBrush program from Z-Soft and is one of the most common (file name extension.PCX). The inability to store color-separated images, insufficient color models and other limitations 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 (file name extension.JPG). Allows you to adjust the relationship between file compression rate and image quality. The compression methods used are based on removing “redundant” information, so 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 images with high color depth, 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. The lossless compression algorithm preserves image information so that the decompressed image exactly matches the original. Lossy compression sacrifices some of the image information to achieve a higher compression ratio. The decompressed JPEG image rarely matches the original exactly, but very often the differences are so small that they are barely noticeable.

JPEG is a compression algorithm based not on searching for identical elements, as in RLE and LZW, but on the difference between pixels. Data encoding occurs 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. For each block, a set of numbers is formed. The first few numbers represent the color of the block as a whole, while subsequent numbers reflect the subtle renderings. The range of details is based on human visual perception, so large details are more noticeable.

In the next step, depending on the quality level you choose, a certain portion of the numbers representing fine details are discarded. The final step uses Huffman coding to more efficiently compress the final data. Data recovery occurs 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, but it is relatively new and is not understood by older programs (before 1995). JPEG does not support indexed color palettes. Initially, CMYK was not included in the format specifications; Adobe added support for color separation, but CMYKJPEG causes problems in many programs. A better solution is to use JPEG compression in Photoshop EPS files, which is described below.

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

From the above, the following conclusions can be drawn. JPEG compresses photographic-quality raster images better than logos or diagrams - they have more halftone transitions, and unwanted interference appears among monochromatic fills. Large images for the web or with high printed resolution (200-300 or more dpi) are compressed better and with less loss than with low resolution (72-150 dpi), because in each 8x8 pixel square, 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 rendering (reproduction) are important, since color information is discarded during compression. Only the final version of the work should be saved in JPEG, because each resaving leads to more data loss (discarding) and turning the original image into mush.

GIF (GraphicsInterchangeFormat). The hardware-independent GIF format was developed in 1987 (GIF87a) by CompuServe for transmitting raster images over networks. In 1989, the format was modified (GIF89a), support for transparency and animation was added. GIF uses LZW compression, which makes it possible to compress files with a lot of uniform fills (logos, inscriptions, diagrams) well.

GIF allows you to record an image “through a line” (Interlaced), thanks to which, having only part of the file, you can see the entire image, but with 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 file is downloaded, the user can understand what is inside and decide whether to wait until the entire file is downloaded. Interlaced notation 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 can contain not one, but several raster images, which 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 particularly evident in connection with the expanded use of electronic publications (in the form of Web pages or Web sites). Despite the ever-increasing capacity 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 effectiveness of an electronic publication largely depends on the quality of graphic elements, and, first of all, on the resolution and color depth of image pixels. Therefore, the desire of 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 have by no means faded into the background. Large graphic files require a lot of 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, GIF files do not need to be archived, as this rarely provides a noticeable gain in volume.

Therefore, the GIF format, whose main advantage is its minimal file size, still retains its significance 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 color mode. This is clearly not enough for printing.

There are two GIF specifications. The first refers to the GIF87a format, which provides for recording multiple images, and GIF89a, which is focused on storing both text and graphic data in one file.

GIF87 a provided the following GIF file capabilities:

Interlacing. At first, only the “skeleton” of the image is loaded, then, as it is loaded, it is detailed. This allows you to avoid loading the entire graphic file on slow lines in order to get an idea of it.

Compression using the LZW algorithm. This feature of GIF files keeps them among the leaders in terms of smallest file size.

Placing multiple images in one file.

Position 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 location in this area.

Subsequently, this standard was expanded by the GIF89a specification, which added the following capabilities:

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

Controls the delay before changing frames (set in 1/100 of a second, or waiting for user input).

Controls the deletion of the previous image. The previous image can be left, replaced with the background color or with what came before it.

Definition of transparent color.

Text output.

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

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

The color depth in PNG files can be any, up to 48 bits. Two-dimensional interlacing is used (not only rows, but also columns), which, just like in GIF, slightly increases the file size. Unlike GIF, where there is either transparency or not, PNG also supports translucent pixels (then available in the transparency range from 0 to 99%) due to the Alpha channel with 256 shades of gray.

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

PNG is supported in Microsoft Internet Explorer version 4 on Windows and version 4.5 on Macintosh. Netscape added PNG support to its browser in versions starting with 4.0.4 for both platforms. However, support for such important format functions as smooth transitional transparency and gamma correction has not yet been implemented.

PNG and GIF89a have the following properties:

The format is organized as a data stream

"Lossless compression"

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

Progressive display of interlaced data

Transparent color support

Ability to store public and restricted data

Independent of hardware and platform

Advantages of PNG over GIF:

Faster progressive display of interlaced patterns

Expanded user data storage capabilities

PNG features not found in GIF:

Storing full color 48-bit images

Storing 16-bit black and white images

Full Alpha Channel

Contrast pointer

CRC is a method for detecting errors in a data stream

Standard toolkit for developing PNG read-write applications

A standard set of test images to test these applications

GIF features missing from PNG version 1.0:

Ability to store multiple images in one file

Animation

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

EPS (EncapsulatedPostScript). A format for describing both vector and raster images in Adobe's PostScript language, the de facto standard in the field of prepress processes and printing (file name extension.EPS). Since the PostScript language is universal, the file can simultaneously store vector and raster graphics, fonts, clipping paths (masks), equipment calibration parameters, and color profiles. The format used to display vector content on the screen is W.M.F. and raster - TIFF. But the screen copy only roughly reflects the real image, which is a significant drawback EPS. The actual image can only be seen at the output of the output device, using special viewing programs or after converting the file to PDF format in the Acrobat Reader, Acrobat Exchange applications.

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 universal way to save data. It uses a simplified version of PostScript: it cannot contain more than one page in one file, and does not save a number of printer settings. 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. It makes sense to use it only when the output is carried out on a PostScript device. EPS supports all color models necessary for printing, among them, such as Duotone, it can also record data in RGB, clipping path, trapping and raster information, embedded fonts. In EPS format, data is saved on the clipboard (Clipboard) of Adobe programs for exchange among themselves.

You can save a sketch (image header, preview) along with the file. This is a low-resolution copy in PICT, TIFF, JPEG or WMF format that is saved with the EPS file and allows you to see what's inside, since only Photoshop and Illustrator can open the file for editing. All others import the sketch, replacing it with original information when printed on a PostScript printer. On a printer that does not support PostScript, the sketch itself is printed. If you work on Photoshop for Mac, save 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 working on a PC or don't know where the file will be used, save the sketch in TIFF format (when given the choice).

EPS has many varieties, depending on the creator program. The most reliable EPS are created by programs produced by Adobe Systems: Photoshop, Illustrator, InDesign. Since 1996, Adobe programs have a built-in PostScript interpreter so they can open and edit EPS. 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 the Save Page As EPS function, and FreeHand editable EPS, created by the Save As function. You should not particularly trust Corel EPS versions 6 and lower and EPS from CorelXARA. EPS files from CorelDraw 7 and higher still have the problem of adding fields to the Bounding Box (a conditional rectangle in PostScript that describes all objects on the page). Before exporting EPS files from CorelDRAW, CorelXARA and, to a lesser extent, from FreeHand, it is worth converting many program effects (translucent fills, for example) into raster or simple vector objects. Thick outlines (more than 2 pt) may have It also makes sense to convert into objects when the program provides such an opportunity. You can check the EPS file with Adobe Illustrator, if it opens, then everything is in order.

PDF (PortableDocumentFormat). Document description format developed by Adobe (file name extension.PDF). Although this format is primarily intended for storing entire documents, its impressive capabilities allow for efficient presentation of images. The format is hardware-independent, so images can be displayed on any device - from a monitor screen to a photo 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, to do this, in most cases you will need the full Adobe Acrobat package, which contains Adobe Acrobat Distiller and Adobe Acrobat Writer.

PDF has been an open ISO 32000 standard since July 1, 2008. The PDF format allows you to embed the necessary fonts (line-by-line text), vector and raster images, forms and multimedia inserts. Supports RGB, CMYK, Grayscale, Lab, Duotone, Bitmap, several types of raster information compression. It 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.

To view, you can use the official free Adobe Reader program, as well as third-party programs. The traditional way to create PDF documents is a virtual printer, that is, the document as such is prepared in its own specialized program - a graphic or text editor, CAD, etc., and then exported to PDF format for distribution in electronic form, transfer to a printing house, etc. .p.

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

The format has been known in the past for low stability and poor file compatibility, however, 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, and multi-page is supported.

Ai (AdobeIllustror). Vector image file created in Adobe Illustrator; instead of raster data, consists of paths or lines connected by dots; may include objects, color and text. Ai documents can be opened in Photoshop, but the image will be "rasterized", meaning that it will be converted from a vector image to a raster image. The AI format encapsulates and formalizes a subset of the PostScript page description language (PDL) in a structured file. These files are designed to be displayed on a PostScript printer, but may also include a raster version of the image, thereby providing a preview of the image. PostScript in its full implementation is a powerful and complex language and is capable of defining almost anything that can be displayed on a two-dimensional output device, an AI format adapted for storing traditional graphics data: drawings, drawings and decorative lettering. Note, however, that AI files can be very complex. PostScript's power comes largely from its ability to define sequences of operations and then combine them using simple syntactic means. This hidden complexity is sometimes (but not always) minimized in Adobe Illustrator files.

File Conversion

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.

Convert files from raster to vector format

There are two ways to convert files from raster to vector format:

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

2) tracing a raster image to create a vector object.

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

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

Original raster image Vectorized image

Converting files from one vector format to another

Vector formats contain descriptions of lines, arcs, shaded fields, text, etc. Different vector formats describe these objects in different ways. When the program tries to convert one vector format to another, it acts like a regular translator, namely:

Reads object descriptions in one vector language,

Tries to translate them into a new format language.

If the translator program reads a description of an object for which there is no exact match in the new format, this object can either be described by similar commands in the new language, or not described at all. Therefore, some parts of the design may become distorted or disappear. It all depends on the complexity of the original image. In Fig. presents one of the possible results of converting a file from one vector format to another. The original image was created in CorelDRAW and consists of the following elements: an imported bitmap image in JPEG format, a frame around the bitmap image, text, and a rectangle with a conical fill.

The main question and topic of our article is formats. Among all the wealth of choice, there is no ideal format that would satisfy all possible requirements. Nevertheless, knowing the future fate of the file - printing, the Internet or simply printing on an inkjet printer, you can properly prepare it and, if not guarantee, then at least maintain hope for success.

All graphic information can be divided into two main groups: vector and raster. Fonts occupy a separate niche in vector graphics.

Raster graphics are a two-dimensional matrix (bitmap) consisting of elementary particles - pixels. The main parameters are size and resolution. The size can be expressed in millimeters, inches, pixels, etc., respectively, this parameter characterizes the horizontal and vertical size of the image. The second main parameter - resolution - characterizes the ratio of the number of pixels per square inch (ppi - pixels per inch or dpi - dot per inch). For newspaper printing, raster graphics should be in the range of 120-150 dpi, for high-quality printing with photo output - 250-300 dpi. Large resolution values are usually redundant and do more harm than good, slowing down the output. Screen resolution is considered to be 72 dpi (in printing it is used only for preview).

BMP(Windows Device Independent Bitmap). Windows native format. It is supported by all graphic editors running this operating system. It is used to store bitmap images intended for use in Windows and this is where its scope ends. Using BMP for purposes other than Windows is a fairly common mistake.

GIF(CompuServe Graphics Interchange Format). The hardware-independent GIF format was developed in 1987 (GlF87a) by CompuServe for transmitting raster images over networks. In 1989, the format was modified (GIF89a), support for transparency and animation was added. GIF uses LZW compression, which makes it possible to compress files with a lot of uniform fills (logos, inscriptions, diagrams) well.

JPEG(Joint Photographic Experts Group). Strictly speaking, JPEG is not a format, but a compression algorithm based not on searching for identical elements, but on the difference between pixels.

The higher the compression level, the more data is discarded, the lower the quality. Using JPEG you can get a file 1-500 times smaller than BMP! Initially, CMYK was not included in the format specifications; Adobe added support for color separations, but CMYK JPEG causes problems in many programs.

JPEG compresses photographic-quality raster images better than logos or diagrams.

TIFF, TIF(Target Image File Format). The hardware-independent TIFF format is one of the most widespread and reliable today; it is supported by almost all programs on PC and Macintosh that are somehow related to graphics. The entire range of color models is available to him from monochrome to RGB, CMYK and additional Pine colors. TIFF may contain clipping paths, alpha channels, layers, and other additional data.

In the TIFF format, it is possible to save using several types of compression: JPEG, ZIP, but, as a rule, only LZW compression is used.

EPS(Encapsulated PostScript). The format uses a simplified version of PostScript: it cannot contain more than one page in one file, and does not save a number of printer settings. EPS is designed for transferring vectors and rasters to publishing systems, and is created by almost all programs that work with graphics. It makes sense to use it only when the output is carried out on a PostScript device. EPS supports all color models needed for printing.

EPS has many varieties, depending on the creator program. The most reliable EPS are created by programs produced by Adobe Systems: Photoshop, Illustrator, InDesign.

QXD(QuarkXPress Document). Working format of the well-known layout program QuarkXPress. The package is characterized by stability, speed and ease of use. The main, never defeated competitor of Adobe Systems continues to exist now in its fifth reincarnation. It should also be noted that two previous versions of QuarkXPress 3.x and QuarkXPress 4.x are still in use. The special ideology of the package lies in its ability to adapt to any layout designer’s tasks. After all, the main functions are performed by special extensions (Xtensions), of which there are more than Plug-ins for Photoshop.

RM(Page Maker). Adobe Systems layout program format. An extremely simple package in terms of capabilities. It was intended primarily for the transition from manual layout to computer layout with minimal costs for staff training. It became widespread among us thanks to timely Russification and, again, ease of learning for beginners. Currently, development of the package has been stopped.

ID(InDesign). Code name "Quark Killer" A follower of RM, designed to squeeze out competitors in the publishing market, primarily Quark. A hodgepodge of solutions borrowed from other layout packages did not lead to the expected result. ID is an extremely clumsy and inconvenient package, which turned out to be the killer only of its progenitor RM, and then because of the cessation of development of the latter.

The only advantages include a built-in PostScript interpreter and apparent ultra-compatibility with other Adobe products.

PDF(Portable Document Format) - proposed by Adobe as a platform-independent format for creating electronic documentation, presentations, transferring layout and graphics over networks.

PDF files are created by converting from PostScript files or using the export function of a number of programs. The format was originally designed as a means of storing electronic documentation. Therefore, all data in it can be compressed, and in different ways: JPEG, RLE, CCITT, ZIP. PDF can also retain all of the output device information that was in the original PostScript file.

Adobe PostScript- page description language. It was created in the 80s to implement the WYSIWYG (What You See is What You Get) principle. Files in this format are actually a program with commands to execute for the output device. Such files contain the document itself, associated files, fonts used, as well as other information: color separation boards, additional boards, screen lineature and halftone dot shape for each board, and other data for the output device.

Data in a PostScript file is usually written in binary encoding. Binary code takes up half the space of ASCII.

CDR- format of the popular vector editor CorelDraw. The package gained its popularity and distribution due to its apparent ease of use and interactive special effects (lenses, transparencies, non-standard gradients, etc.). The wide capabilities of this program in terms of effects are explained by a richer internal page description language than that of Adobe products that use PostScript. This is precisely the main disadvantage of CorelDraw. PostScript with Korelov special effects is often a headache for printing houses and prepress bureaus.

CCX- vector graphics format from Corel. It is not supported by anything other than CorelDraw. Unsuitable for printing and the Internet. The advantages include only a small volume of files saved in this format and the presence of many excellent cliparts.

Vector graphics are a mathematical description of objects relative to an origin. Thus, to display a straight line, the coordinates of only two points are required. For a circle - coordinates of the center and radius, etc.

Graphic formats can contain a lot of additional information: alpha channels, paths, color model, raster lineature and even animation. The choice of format for printed products primarily depends on the output device. Phototypesetting machines operate under the PostScript language. Therefore, for printing, the main data storage formats are TIFF and EPS. Accordingly, the format is raster and vector graphics. Recently, PDF (Portable Document Format) has been gaining momentum.

TIFF Only suitable for transmitting raster graphics. This format allows you to store a lot of useful information: alpha channels, color model, paths and even layers (when using Adobe Photoshop 6-7). However, to improve output reliability, many prepress bureaus do not recommend leaving additional channels and layers in the final files. To be on the safe side, if it is not possible to consult with the printing house, it is also better to disable compression. You should also not save text labels and vector graphics in TIFF format. Even with a resolution of 300 dpi, they will look like a sawtooth effect when printed. In order to avoid such defects, the EPS format is provided, which allows you to contain raster and vector graphics, fonts and other useful information. However, quite often we encounter this curious misconception: when opening an EPS file (created using Illustrator or Corel Drow) with the raster graphics program Photoshop, users continue to firmly believe that they are still working with vector graphics. No, my dears, no matter what format you save it in, the output you will get is only a raster and nothing more. By opening any file with vector graphics in Photoshop, you rasterize it, that is, turn it into a raster format. The only exception can be EPS created directly in Photoshop versions 6-7. Fonts and vector primitives, in this case, will remain vector in the output. This format is called Photoshop EPS. There are quite a few varieties of EPS, they differ in the presence of preview images, composite or separated images, encoding and compression. But they all agree on one thing - EPS is based on the PostScript page description language, which in turn is a standard for printing output devices. Therefore, it should be taken into account that all files in other formats, such as CDR and CCX, must be forcibly converted to PS. At the same time, commands from one language are not always adequately translated into another, and the result of such a conversion can be, at best, damaged films, or, at worst, the entire circulation. Therefore, the attitude of printing house workers towards such formats and programs is appropriate. However, this does not mean that everyone should prepare vector graphics in Illustrator and raster graphics in Photoshop; it’s just that when preparing graphics in another package, you need to limit your flight of “fantasy” and especially carefully check the output files for PostScript errors. Unlike other packages, Adobe Illustrator was designed as an interface to the PostScript language and does not need to convert its files to produce a format understandable for the output device. In the ninth and tenth versions of Illustrator, the base format is PDF, which is also not a problem for output, because it is essentially "refined" EPS. All previous versions are based on PostScript.

Don't forget about fonts. Often, only the names of fonts appear in the EPS file and others are substituted during output, which in no way corresponds to the designer’s intention. Therefore, fonts must be converted to curves, either embedded in a file, or attached as separate files.

We all know that absolutely all files have their own specific extension. Photos - jpg, music files - mp3 and so on. The file name can be whatever the user wants, but it is not recommended to change the file extension. Sometimes changing the extension can corrupt the file. So be careful about this. Let's look at the most popular file extensions that we come across almost every day:

Archive extensions:

ZIP is a file using ZIP compression, which is supported by almost all archivers.

RAR (Roshal ARchive)– this is already a file using RAR compression. The compression ratio is much higher than ZIP compression.

Video extensions:

AVI– one of the most popular video file extensions. The compression ratio is lower than that of similar video formats. This format is played in almost all video players.

MPEG1-2(MPG)– expansion of audio and video storage with data loss.

MPEG4(MP4)– this format is very often used to transfer files on the Internet.

Graphic extensions:

GIF (Graphics Interchange Format) - format for network distribution. The files are very small in size. Supports animation.

BMP– raster format. The most common graphics format in Windows. Almost all graphics programs can create and read the BMP format. Standard graphics file format for Windows. Almost all Windows image editing programs can create and read BMP files. An image with a .BMP extension cannot be compressed.

JPEG(JPG)– very often used for raster images (drawings, photos). Excellent compression ratio allows for downsizing. But I would like to note that when compressing a file, the quality of the compressed image may be lost. The JPEG format is one of the best formats in the field of photographs and images, as it supports a large number of colors. (16.7 million colors)

PSD (Photo Shop Data)– Photoshop processing format.

TIFF(Tagged Image File Format)– very widely used by digital technology users. It is compressed without data loss, which is a big advantage over other formats. The number of colors is approximately the same as the JPEG format - 16.7 million colors.

Document formats:

DOC– I think this is the most famous format :) Belongs to the Microsoft Word program. Contains both text and graphs, pictures, tables, diagrams, etc.

PDF (Portable Document Format)– This format belongs to an equally well-known program - Adobe Acrobat. Mainly intended for electronic presentation of printed products. To display this format, the free Adobe Reader program is used.

TXT– a document containing unformatted text. In Windows, it is created and opened with regular notepad.

Music formats:

MP3– the compression ratio is approximately the same as that of the JPG format. But naturally, with strong compression, the sound quality deteriorates significantly.

WAV– a format from Microsoft that is used in Windows. Since this format has large file sizes, it is very inconvenient for transmission over the Internet.

WMA (Windows Media Audio)- another music format from Microsoft for storing audio information. Has a good compression ratio.

There are several extensions used for each file type. This is because they are processed by different programs that encode them based on content, compression, and other features. Graphic file formats can be divided into raster and vector. If you are going to get acquainted with computer graphics, then you need to know everything about them. File formats play an important role in preparing print layouts, designing, placing images on Web pages, and many other types of work.

Raster type of graphic images

Raster graphics are based on pixels that are organized into rows and columns. They represent surface rendering elements. They are independently assigned color, transparency, and other properties. Image quality and pixel count are related: the more pixels used, the better the final image will look.

Raster graphics have several advantages:

wide scope of application (with their help you can transfer objects of the real world using photos);
graphic information is easy to process;
printing can be done on any equipment; standard printers easily construct an image from pixels;
Most raster formats are accepted by any program for processing and displaying images on a monitor.

But when working with them, you need to take into account a number of disadvantages:

The file size can be very large, which will make it difficult to transfer (this most often happens with uncompressed images);
editing a raster image is more difficult, since the pixels become an integral part of the overall picture, and are not perceived as independent units;
formatting and transformation can distort the image.

Nevertheless, we come across raster images most often. Any camera creates images in this format.

In what formats are raster files saved?

Popular raster graphics file formats can be found on every computer. Most of them you have seen on your device. Raster formats include:

Bit Map (BMP, extension - bmp) is a file with the most wasteful encoding, one of the standard graphic formats used in the very first versions of Windows. Initially, only 256 colors were available to users, and each pixel was equal to one byte. Now you can use BMP to store full-color pictures. The main program for working with it is Paint, but you can open it through Photoshop and other editors.
Tagged Image File Format (TIFF, tif extension) is a universal cross-platform format used to transfer images between users. It is most often used in publishing and in the preparation of topographic maps, since it can be used to obtain a clear image on a printed version of the picture. Installed by default in utilities that work with scanners and faxes. Not suitable for websites as images are heavy. It is best to work with it using the FastStone program - it allows you to view the contents of the file, process and convert it.
Graphic Interchamge Format (GIF, extension - gif) is a format that supports animation without losing information during compression. Widely used on the Internet, despite the limited number of colors. The appearance of the image does not change when used to view different browsers and platforms. The following programs work with the format: Viewer, Paint, Adobe Photoshop, Visio.
PhotoShop Document (PSD, extension - psd) is an internal raster graphics format used for the Adobe Photoshop software package. Its peculiarity is that the image retains all layers and can therefore be easily edited.
Portable Network Graphics (PNG, extension - png) is a free format in which the image is compressed without loss, which allows it to be used in various areas of computer graphics. Work with this program format : Viewer, Paint, Photoshop, Visio, Corel PaintShop Pro.
Joint Photographic Expert Group (JPEG, extension – jpg) – stores images by compressing them. This format is considered the standard for full-color images. It is used to record pictures taken from cameras and is used in computer graphics. It features a smooth change in brightness and color in the work area. During compression, data that does not have a significant effect on the final image is excluded from the file. The entire drawing is divided into rectangular areas, sometimes resulting in a blurry image. Image processing can be carried out using the following utilities: FastStone Viewer, Paint, Adobe Photoshop, Visio.
Joint Photographic Expert Group 2000 (JPEG 2000, extension - jp 2) - allows you to get sharper images when compressed, while the file weight becomes smaller. It is processed by the same programs as its prototype. It is not very common because not all browsers support it.
Windows I con (ICO, extension - ico) - used to create small format images and icons. These images mark sites in the address bar or in the “Favorites” bar of browsers. The following programs are used to work with this format: Inkscape, Newera Iconcool Editor, Sibcode Sib Icon Editor.
RAW (extensions: ari, dpx, arw, srf, sr2, bay, crw, cr2, dng, dcr, kdc, erf, 3fr, mef, mrw, nef, nrw, orf, ptx, pef, raf, raw, rwl, dng, rw2, r3d, srw, x3f) is a form called digital negative. Used when saving images with professional cameras. There is no general standard for expanding this format, so each equipment manufacturer creates its own version and software that can work with it and convert it into other generally accepted options.

The variety of graphic file formats can confuse even a professional, so many programs are able to work immediately with files with different extensions. One of them is Photoshop, which is the most popular among users.

Vector type of graphic images

Advanced users know another type of images built on the basis of regular structures. In a primitive sense, vector graphic file formats are a diagram that is made up of the simplest shapes: triangles, segments, straight lines, rectangles and others. The advantages of vector files are:

small file size if the drawing is made up of graphic primitives;
scaling occurs without loss of quality;
When outputting vector images, the maximum resolution of the printer or other device is used.

Such images have a number of significant disadvantages:

You cannot create realistic images using vector graphics;
it is impossible to automate the input of graphic information due to the heterogeneity of the elements;
Each program has its own format in which it saves images; the files depend on the utilities.

A large number of programs used to work with vector graphics were created because each of them performs its own tasks. Unlike raster images, vector images are used in design, architecture and other areas. Often, working with drawings requires high precision and a wealth of special knowledge.

Vector image formats

The most common vector graphic file formats are:

CDR (cdr extension) is an internal format of the CorelDRAW software package. Allows you to save images created in this program and text. This software package can also use other special formats: CDT, CDX, CGM, CLK, CMX, CPX, CSL, DES, DRW, DSF. Some of these formats support the combined use of raster and vector graphics. They are used for various CorelDRAW applications and can be used to create different images, templates and video clips.
AI (ai extension) is a format used in Adobe Illustrator. When working with this file, it is worth remembering that a file created on a recent version of the software cannot be opened on an outdated version of the utility. This format is loved for its high quality graphics, but its drawback is that a number of effects are lost during its conversion, for example, gradient fill.
EPS (eps extension) is a format supported by many vector graphics programs. It has several versions, which are indicated by digital values, but many programs do not support EPS above 7. Thanks to this format, conversion is resorted to in extreme cases, because it is much easier to save the file in it than to restore lost properties later.
DXF (dxf extension) is a format with which AvtoCAD design applications and its analogues work. The files support many features not found in other vector-based options, such as saving 3D objects.
WMF (wmf extension) - used to work with applications based on Windows OS. This is a universal tool used to display images on computer screens and printers.
SWG, SVGZ (extensions - swg, svgz, differing in the percentage of image compression) - a format used to design web pages. All popular browsers support it. It cannot be used to store complex designs, so its scope of use is very limited.
TGA (tga extension) is a popular format used in motion graphics and video editing. Information is stored at a depth of 32 bits per point. This is a universal file option that can also be used to store raster images.
FLA, FH (extensions fla , fh ) – used to store the original versions of Flash images. Open only on Adobe software. In particular, they use the Flash program and the vector editor FreeHand.

The popular format for PDF documents can also be classified as vector. Initially, it was not planned that it would be used to transfer images, but now more and more often users save information mixed in content - text and graphics - in it. In this case, the illustrations in this document can be either vector or raster. The text part contains a large number of fonts. This format was also presented to the world by Adobe.

How to change image formats?

The need to convert one file format to another most often arises for the following reasons:

software incompatibility with the current extension;
there was a need to reduce the size;
you need to process the file in another program, and not in the one in which it was created;
to meet the requirements of the file hosting environment (for example, when placing graphics on a web page).

Conversion of graphic file formats is carried out using utilities. For example, in Adobe Photoshop you can save files with an extension other than just for internal use. Using the “Save for Web” command, about a dozen popular raster formats will be available to you. Other programs for working with images have similar capabilities; for example, in CorelDRAW you can not only change the format of the created graphics, but also transform the vector version into a raster one.

You can also use separate applications called converters for transformation. Most have a wide range of available formats, but it's best to use options that only work with a few extensions. Examples of the best graphics conversion utilities:

Flash-SWF to AVI/GIF/MP3 Converter;
FormatFactory;
VeryDOC EMF to EPS ;
Image Converter;
DWG to BMP;
Aunsoft SWF Converter;
Uniconvertor;
GraphicsConverterPro ;
Converter 3Plus;
Solid Converter DWG;
Photo to PDF;
Raster to Vector SDK.

Most programs work with vector files, since they are most common and not only professional designers and planners work with them.

Another opportunity to convert and work with files is provided by plugins that complement standard graphic editors. One of them is Irfan View. It allows your software to work not only with basic extensions, but also with more than 20 other formats.

Now you know what the graphic file formats are. This article lists basic information about them. We recommend saving it and sharing your new knowledge with friends. You can also ask questions in the comments and tell them about your experience working with graphics.