In what format are vector images saved? Vector graphics formats. Other vector formats

Graphic file formats

• by Igor Skrynnikov
• 01/10/2008
• 3 comments

File formats are the basis for working with digital photographs. FotoTips.ru will tell you about all the main graphic file formats.

A file format containing raw information coming directly from the camera sensor. These files are not processed by the camera's processor (unlike JPG) and contain original shooting information. RAW can be compressed without losing quality.

The advantages of RAW are obvious - unlike JPG, which was processed in the camera and already saved with data compression - RAW gives the widest possibilities for processing photographs and maintains maximum quality.

Note. Various manufacturers Photography technicians use different algorithms to create RAW in their cameras. Each manufacturer comes up with its own resolution for its RAW file - NEF - Nikon, CR2 - Canon...

JPEG (aka JPG).

This is the most common graphics file format.

JPG has earned its popularity due to its flexible data compression capabilities. If necessary, the image can be saved from maximum quality. Or compress it to the minimum file size for transmission over the network.

JPG uses a lossy compression algorithm. What does this give us? An obvious disadvantage of such a system is the loss of image quality every time a file is saved. On the other hand, image compression simplifies data transfer by 10 times.

In practice, saving a photo with minimal compression does not result in any visible degradation in image quality. That is why JPG is the most common and popular format for storing graphic files.

The TIFF format is very popular for storing images. It allows you to save photos in various color spaces(RBG, CMYK, YCbCr, CIE Lab, etc.) and with high color depth (8, 16, 32 and 64 bits). TIFF is widely supported graphic applications and is used in printing.

Unlike JPG, a TIFF image will not lose quality every time the file is saved. But, unfortunately, precisely because of this TIFF files weigh many times more than JPG.

Right to TIFF format V at the moment owned by Adobe. Photoshop can save TIFF without merging layers.

The PSD format is used in Photoshop. PSD allows you to save a raster image with many layers, any color depth and in any color space.

Most often, the format is used to save intermediate or final results of complex processing with the ability to change individual elements.

PSD also supports compression without loss of quality. But the abundance of information that a PSD file can contain greatly increases its weight.

The BMP format is one of the first graphic formats. It is recognized by any program that works with graphics, format support is integrated into operating systems Windows and OS/2.

BMP stores data with color depth up to 48 bits and maximum size 65535x65535 pixels.
For now BMP format practically not used either on the Internet (JPG weighs several times less) or in printing (TIFF copes with this task better).

The GIF format was created in the early days of the Internet for sharing images. It can store lossless compressed images in up to 256 colors. The GIF format is ideal for drawings and graphics, and also supports transparency and animation.
GIF also supports compression without loss of quality.

PNG format designed to both improve and replace GIF format graphic format that does not require a license for use. Unlike GIF, PNG has alpha channel support and the ability to store an unlimited number of colors.

PNG compresses data without loss, which makes it very convenient for storing intermediate versions of image processing.

JPEG 2000 (or jp2).

A new graphics format created to replace JPEG. With the same quality, the file size is JPEG format 2000 is 30% less than JPG.

With strong JPEG compression 2000 does not split the image into squares that are characteristic of the JPEG format.

Unfortunately, at the moment this format is not very widespread and is only supported Safari browsers and Mozilla/Firerox (via Quicktime).

Vector graphic formats files

ai
Vector file format, created by the program Adobe Illustrator. In Adobe Illustrator large number versions - Adobe Illustrator 3, Adobe Illustrator 4, Adobe Illustrator 5, etc. ai format of each new version incompatible with older versions, which means for example a file saved in Adobe versions Illustrator 9 can be opened in a newer version of the program (Adobe Illustrator 10, CS, CS2, etc.), but cannot be opened in a newer version old version programs (Adobe Illustrator 8, 7, 6, etc.), although Adobe Illustrator 10 supports the ability to import files of newer versions. The format provides very high quality drawings, but due to a number of parameters it is poorly compatible with other programs (for example, various Adobe effects Illustrator and gradient fill may not transfer to other formats).

cdr
Vector file format created by CorelDraw. CorelDraw has a large number of versions - CorelDraw 3, CorelDraw 4, CorelDraw 5, etc. cdr format each new version is incompatible with older versions, which means, for example, a file saved in CorelDraw versions 9 can be opened in a newer version of the program (CorelDraw 10, 11, 12, etc.), but cannot be opened in an older version of the program (CorelDraw 8, 7, 6, etc.). The format provides very high quality drawings, but in a number of respects it is poorly compatible with other programs (for example, various CorelDraw effects and gradient fills may not be transferred to other formats).

cmx
Corel Presentation Exchange - format graphics programs Corel Corporation, designed to transfer drawings between different programs. The format is supported starting from CorelDraw 6.

eps
A relatively universal vector file format, supported by most vector editors - CorelDraw, Adobe Illustrator, Macromedia FreeHand and various highly specialized programs (for plotter cutting, engraving, wood burning, etc.). The format has many versions and, unfortunately, each program only supports it up to a certain version (for example, CorelDraw only supports versions up to EPS 7). The format provides very high quality drawings.

fla, fh
Flash source files are created in Adobe Flash(formerly Macromedia Flash).

svg
Abbreviation from English. Scalable Vector Graphics. It is an open standard, i.e. Unlike most other formats, SVG is not proprietary. This is based on XML language markup designed to describe two-dimensional vector graphics. The format is supported by many web browsers and can be used to design web pages. Unfortunately, the format does not provide high quality for complex drawings and has limitations in its scope of use.

swf
Flash format that can be viewed from using Flash Player, installed as a browser plugin.

wmf
Windows Metafile is a graphical file format in Microsoft system Windows. A universal vector format supported by most vector editors. Unfortunately, the format does not provide high quality for complex designs and has a very limited number of supported effects, so for professional use is not suitable and is used mainly by private users. The format is supported by a number of web browsers and can be used to design web pages.

The EPS (Encapsulated PostScript) format is a standard for vector-based images that need to be placed into a page layout program. An EPS file is a PostScript code containing a precise description of the design that will be used for printing. Additionally, the EPS includes a low-resolution image for preview(preview, not to be confused with thumbnail - a miniature on the file icon). Preview makes it easier to identify images during layout and allows you to visually control its position, scale and rotation.

How to get a vector file in EPS format?

Adobe Illustrator is the only vector editor for which EPS format- practically native. Prior to version 8 of Illustrator, EPS was its internal format (available in the Save as > Illustrator EPS menu), and the Illustrator format (*.ai) differed from it mainly in that it allowed some of the additional editing capabilities available in Illustrator to be retained. Starting with version 9, internal EPS was replaced by PDF, a format also created and successfully promoted by Adobe, although the Save as EPS option is still available. PDF format introduced many new features in the creation of drawings (effects based on the transparency of elements (normal transparency) and various methods of overlaying colors ( blending mode), similar to those used in Photoshop), but at the same time made it difficult to record in EPS format, which does not support transparency. Thus, when recording EPS, transparent elements are converted into rasterized objects, and exactly how this happens is controlled by the settings of the Document Setup > Transparency dialog box. In the 10th version of Illustrator, another means of controlling the processing of transparent objects has appeared - this is the optional (not connected by default) Flattening Preview plugin. When installing the program, it is located in the Utilities folder (there is also a PDF file with its description), and in order to use it, you need to transfer or copy the Flattening Preview.aip file to the Plug-ins folder. This plug-in makes it possible to see in the preview window which objects and how will be processed when saving the EPS version of the image. Despite quite ample opportunities settings, you should be careful when saving graphics that contain transparent elements in EPS format. If quite a lot of various transparencies are used, it is possible the best way out There will be a complete conversion of your drawing into TIFF raster format. At the right approach This transformation ensures that the design remains of high quality.

In the FreeHand program, saving a picture in EPS format is done through the Export menu. Before this operation, you need to decide whether any editing of the file will be required after this or not. The fact is that FreeHand, when exporting to EPS, offers the Include FreeHand Document option. If the option is activated, a second version of the drawing in the native format of the program is written to the EPS file - and then FreeHand will be able to open the file. If the option is disabled, the EPS file will only contain PostScript code, and FreeHand will only be able to open a preview version, which cannot be modified in any way. Keep in mind that prepress specialists clearly prefer to deal with EPS files, and not with “hybrids” EPS+FreeHand, as this avoids possible errors output and reduces file processing time. Once the issue with the mentioned option is resolved, select the EPS option for Mac platforms or Windows (Macintosh EPS/EPS with TIFF Preview) - and get a file to be placed in the layout.

CorelDraw! also allows you to export your drawing to EPS format. The export procedure itself is not complicated, but few people would dare to predict what Corelov's EPS will look like on color-separated films and, therefore, on paper. Unlike Illustrator CorelDraw! does not in any way regulate the rasterization of “dangerous” transparent elements. As a rule, the simpler the original drawing was in execution, the greater the chance that everything will work out without problems. If there are still problems, it is better when this is clarified at the photo output stage. Depending on the essence of the error and the model of the phototypesetting device, one RIP may issue an error report, another will simply freeze hopelessly, but the third will not issue any warnings and will output what it was able to render - and then, if you do not want to get a defect in the print run, Review the received films very carefully. Be aware that there is an opinion among prepress specialists: what is started in Korel should be finished in Korel. This means that it is safer to write a print file (*.ps) directly from CorelDraw!, since apparently no other program knows better than it how to process the drawings it creates, not only effects, but even plain text.

The EPS file is ready. What's next?

Next, we put it into the layout program. This is its direct purpose. But its use does not end there, although other options are a “side effect” of versatility of this format. For example, the resulting EPS can also be placed in a vector graphics program. And even into the program raster graphics. Let's consider the options.

Putting EPS into the layout

First, a couple of notes about EPS in page layout software. All programs of this kind allow you to transform placed images quite arbitrarily, which is sometimes used inexperienced users. It is important to understand the following: in a layout program, transforming a placed EPS file is permissible only within very limited limits, and you need to be aware of what exactly is happening, and it is better to carry out all transformations with the original file in the program in which it was created.

The only absolutely “safe” action is moving the EPS around the page or in a mask (box in QuarkXPress or frame in PageMaker). Turning is not very desirable, but quite acceptable. It may require additional efforts by the layout program to process the image and even redraw the screen, and, in the case of an extremely complex vector original, it may cause a photo output error. The most undesirable transformation is scaling. The point is that scaling not only requires increased resources processor to recalculate changes, but also makes adjustments to such critical parameters as line thickness, gradient size, trapping values, pattern fill type and others. For example, in a vector original there is a drawing made with a line 0.1 pt thick, which, when reduced by 50% in a layout program, will turn into 0.05 pt and may simply not appear on color-separated film or paper. Likewise, trapping done using a vector package can either become too noticeable (at scales greater than 100%) or insufficient (at scales less than 100%).

To summarize: you can move it arbitrarily, rotate it at any angle – you can be careful, and scale it – it’s undesirable.

Vector EPS in Photoshop

In Photoshop, the Place command places the selected file in open image in the form of an object (preview in an “envelope” - a crossed out rectangle), which can be transformed if necessary, and then double click mouse or the Enter key to embed it on new layer. EPS is immediately rasterized to the resolution of the file in which it is placed. This procedure can be useful when you need to place some vector art (for example, a logo) into a raster sketch, which you also use in other sketches and therefore want to preserve the vector-quality version.

At the same time, vector EPS You can simply open it in Photoshop. A dialog box that appears will ask you to select the dimensions, resolution, and color model of the image you want to obtain. By default, the size of the source vector file is suggested, and the resolution is 72 dpi or whatever you used last time in this dialog box. The result can be dragged-and-dropped to another raster file, and if you know the resolution of this target file, select the same resolution for rasterizing EPS to avoid the need to scale the resulting raster layer, since each such transformation will inevitably lead to a greater or lesser loss of quality.

Using the Open command followed by rasterization, you can get a raster version of the vector original while maintaining the highest possible quality, and given that Photoshop can do rasterization much better than vector programs, this is how you should convert complex vector files(for example, Illustrator 9 or 10 files containing transparency effects) into raster format.

Is it necessary or not?.. But it’s possible

That's right - it is possible to place a vector EPS into a vector graphics editor document. Reasons? Well, let's say...

For some reason you are doing the color separation (writing the PS file) directly from the vector editor. You have a vector EPS created in another program (not necessarily in vector editor); You don’t have such a program, and when opened in the editor you have (that is, when converted to this editor’s own internal format), the file is interpreted with errors (unfortunately, not all vector programs equally accurately recognize an EPS file created by another program, but layout packages do this as correctly as possible, provided that the file was created correctly). A way of placing this EPS while maintaining a link to the original may solve the problem. Perhaps the situation described is somewhat far-fetched, but who knows, maybe the situation that you will one day have to face will be even more unexpected.

What you need to be especially careful with is not the placement, but the implementation of EPS (without connection with the original) into a vector editor document. Some objects may be interpreted incorrectly, or some undesired attribute may be assigned to them. For example, Illustrator version 8 allows you to assign anyone vector object output resolution parameter, i.e. the resolution in which the processing will be processed this object when printing. So, for some unknown reason, Illustrator assigns 300 dpi to objects of embedded EPS, even if created correctly, although the default value for the document is 800 dpi. When outputting to film, this can manifest itself in a gross distortion of smooth lines - they are transformed into short straight segments, quite noticeable upon careful examination - the so-called “nut effect”. This “misunderstanding” grew into a problem in versions 9 and 10 of Illustrator, where only the permission attribute is saved for the entire document and changing it at the level of an individual object is not available. By the way, for vector files of Korelov origin, placed and even copied into Illustrator 8, the output resolution of objects is always 300 dpi and requires correction.

Other ways to obtain an EPS file

You can convert a page from a layout program to an EPS file. In Quark, this is done using the Save page as EPS command. In PageMaker, the same result can be achieved using the Print command, where in the print settings you need to specify Print to file > EPS. The resulting EPS can, in principle, be opened and modified in a vector editor, although some difficulties may arise with the accuracy of the interpretation of some objects, with the conversion of font encodings and other, more specific problems. Fewer problems arise if the resulting EPS is used for layout in the same layout program from which it was obtained. For what? Agree that, for example, when mounting individual pages of a multi-page work onto a printed sheet, it is easier to operate with EPS files than with complex groups of objects different formats and origin. Even more correct layout methods are described in the article on layout programs.

Other vector formats

First of all, these are native formats of well-known vector editors - Illustrator, FreeHand, CorelDraw!. As a rule, they are poorly compatible with each other, since they support very different ways of describing objects, effects, and editing capabilities that are specific to each of them. However, sometimes in one editor you can open a file created by another (manufacturers provide appropriate import filters for this), but this is fraught with the loss of some of the features inherent in the original program and will most likely require modification to return lost or distorted details of the drawing. If you are going to allow someone to open your drawing in another vector program, save a copy of it in an earlier version of the editor than the one you are using. This will increase the likelihood of it being interpreted correctly by the import filter.

You should not experiment with placing vector drawings in the layout of your editor in the native format - even if such compatibility (in the form of an import filter) is provided, it does not guarantee error-free processing of this file when printing and is only acceptable at the stage of preliminary layout sketches.

Raster in vector. Problems of coexistence

Vector programs allow the inclusion of raster images in their documents (which do not become vector images! - note especially for dummies), but this feature should be used carefully. The first problem you will notice is the significant increase in the file size of the vector document and therefore the print file; Screen redrawing usually slows down as well. The second, less obvious problem has to do with how builtins are handled. raster image– mainly in relation to color. If used in a vector editor color settings(read, profiles) that differ from the settings used when creating the raster file, the result of color transformations may be difficult to predict. This does not apply to linked raster EPS - its parameters are untouchable. Therefore, if the premises raster object You can’t avoid it in a vector drawing, place a linked EPS. But know that the most correct way to combine both formats - the only one that is 100% correct and does not cause any complaints from prepress professionals - is to do this in a layout program.

References

To prepare this work, materials from the site http://best-sell.ru/ were used