An EPS image or file is a vector file that facilitates the inclusion of illustrations and images into text-based files or documents meant for printing. The file format may contain 2D texts, raster images, and vector graphics. EPS stands for Encapsulated PostScript and is identified using the .eps file extension.
Unlike other file raster graphics formats such as PNG, SVG, or JPG, vector files like EPS can be scaled limitlessly without degrading image quality or resolution. This is because EPS files consist of complex mathematical formulas comprising shapes, lines, and points.
The scalability and high-resolution capabilities of EPS files make them highly suitable for large-scale print designs such as billboards, banners, and posters. As a vector-based format, EPS is a widely accepted choice in the professional printing industry, and it is known for maintaining high quality across various sizes.
Its closest variation is the PostScript (PS) file format. PS existed as a scripting language that propelled the development of the Encapsulated PostScript. While PS is a powerful page description language, EPS files extend this functionality by encapsulating PS commands with additional structure and portability features, such as a preview image and standardized bounding box definitions.
EPS files are widely supported by computer software and systems like QuarkXPress, Freehand, CorelDraw, Illustrator, MacOS, Linux, and Adobe Photoshop. However, an EPS file can hardly be edited after being saved, compelling users to get the initial design files for error correction.
History of EPS Files
Adobe Incorporation created the Encapsulated PostScript (EPS) file format in 1987. The format was intended to facilitate the incorporation of illustrations and graphics into textual files or documents intended for printing.
The design and printing industry could hardly offer digital files to meet and serve printers' and designers' demands. This prompted Adobe Systems to create EPS files, which could logically enable image printing in different sizes.
EPS also allowed rendering in preview before printing, an impossible feature in previous file formats. Since most prominent image setters, printing equipment, and design software are compatible with EPS, most designers adopted the file format during its inception and afterward.
Finally, EPS images set the mark of becoming a business standard for professional printers. Their images or files were widely used in advertisement banners, billboards, icons, logos, marketing materials, scientific printing, and publishing charts and graphs.
The emergence of next-generation file formats like SVG and PDF has outshined the Encapsulated PostScript vectors. Despite losing their popularity to these file formats, some print professionals still use EPS files owing to their backward support feature, which allows them to be used with outmoded printers.
Properties of EPS Files
EPS files can contain raster and vector graphics data, including images, drawings, and texts. The components of an EPS file are apparent in its structure, storage, browser support, compatibility, compression mode, support for transparency and animation, and ability to be edited and resized.
Structure
EPS is primarily a vector graphics file type that comprises mathematical equations that define the image colors, lines, and shapes. Such graphics comprise curves and lines rather than pixels, distinguishing them from other raster file formats.
However, the EPS file format includes 3D geometry, texts, and other raster graphics. It can combine both vector and raster graphics functionalities, making it a versatile tool for professionals, designers, and amateurs.
An EPS file extension structure has a file header, PostScript Program, encapsulated image data, and an end-of-file marker. The header contains primary information about the file, including the resolution level, the bounding image box, and its version number.
The PostScript Program stores the PostScript instructions used in rendering the image. Conversely, the encapsulated image data comprises the palette information, color depth, and image pixels. Finally, the end of the file marker shows the end of an EPS file.
An EPS file is information-rich and high-quality. Its file information or data benefits from lossless compression, which ensures the image quality remains high even with upward or downward scaling. The file format is one page long, with a limit of 0.5MB and 10 MB.
EPS files or images contain bitmap data, retaining individual coding on color and size. This implies that the image data it preserves ensures that the resolution levels remain high regardless of scale. It supports both CMYK, Grayscale, and RGBA color profiles but hardly supports the ICC profile.
The file format allows users to save the header in black and white, 4-bit grayscale or color, and 8-bit grayscale or color. However, the EPS preview header is 32 bytes in length. On the other hand, the EPS read supports 1-bit, 8-bit, and 24-bit color channels.
Although not pixel-based, the PostScript programming language in EPS allows color integration in its multiple files. The 8-bit displays only 256 colors, while the 24-bit displays over 16 million colors. EPS is a vector graphics file format and does not allow multi-sample pixels.
The header resolution can be between 1 and 300 dots per inch (dpi), which makes it both a high- and low-resolution format. The default header resolution is 72 dpi. The bit depth and resolution level show how detailed an image is and its quality.
Storage
EPS files can store uncompressed and compressed data, including vector graphics, lines, text, and other document elements. The format is designed to preserve all image information, minimizing the chances of quality degradation for vector graphics. Although EPS is primarily a vector format, it can also include raster data, ensuring versatility in the types of content it can store.
Lossless EPS data can be stored indefinitely as there is no image degradation over time. The storage mediums for EPS images include Content Delivery Networks, Floppy Drives (FD), Hard Drives (HDD), File Systems, Base64 Encoding, and Cloud Storage.
Compression
EPS image data can be compressed using a lossless technique. This ensures the picture quality remains high, even when the file is downsized. Often, EPS files are uncompressed, although the file format supports lossless LZW and ZIP compression. However, the file format does not permit variable compression.
The table-based lookup algorithms remove redundant or replica EPS image data and then compress the remaining information of the original file into a smaller file using LWZ encoding algorithms.
The file compression rate for PackBits (ZIP) expressively minimizes EPS files by 10% to 20%. However, the compression rate of EPS files can sometimes be zero when non-photographic EPS files or images are handled.
EPS file compression is important to minimize file sizes, save bandwidth, preserve image details, and improve web performance. Nonetheless, EPS tends to retain image quality exchanges with larger file sizes. EPS larger file sizes reduce web responsiveness or increase website loading time.
Editing
The EPS file can be edited in software supporting vector graphics, including CorelDraw, QuarkXpress, Inkscape, Adobe Illustrator, Photoshop, GIMP, Paint.Net, and InDesign.
An EPS image can be resized using the most popular software or programs for creating this file format, including Adobe Photoshop, GIMP, GhostScript, Inkscape, CorelDraw, and Adobe Illustrator. These are vector graphics editing and resizing tools applicable to EPS.
Animation
Encapsulated PostScript or EPS files do not support animation. The file format was designed to support still images or content and has no multimedia or live content capabilities to support animated images or animations. EPS files are meant for professional printing and are not ideal for screen-based displays.
Transparency
EPS files do not have inherent support for transparency or transparent backgrounds, which is an obstacle when working with design elements or layered images that require them. An EPS file's fundamentals are its textual form, which uses the PostScript programming language.
Humans can read EPS files. Although PostScript is a completely functional programming language and can describe graphics in more complicated ways, the PostScript interpreter is ideal for rendering an EPS file for review.
Best Use Case of EPS Files
- EPS files have been widely adopted and used in printing and designing graphics for:
- Billboards: Vector files store individual image data, meaning they retain high resolutions irrespective of the scale used. Thus, EPS files are suitable for expanded images, including large-scale advertising collateral or billboards that can be read from a distance.
- Printing: The EPS format's backward support suits professional printers carrying out large-scale tasks. EPS files are used in various printers, including those that outdated modern file formats hardly use, including PDF. EPS data are also quickly rendered in detail using computer-controlled engraving machines.
- Legacy Format: EPS file format still functions as a legacy format supported and compatible with various software programs, systems, and applications, although modern file formats, including PDFs, have overtaken it.
Unrecommended Use Cases of EPS Files
- Transparent Artwork: Unsuitable for artworks with transparent backgrounds, the file information will flatten and be lost when saved as EPS.
EPS Browser Support
EPS is supported by Browsers such as:
- Google Chrome
- EPS files are not supported in almost all modern and older Browsers, such as:
- Safari
- Internet Explorer
- Opera
- Firefox
- Microsoft Edge
Users must add PostScript Viewer and Compiler extensions to Google Chrome to open and view EPS files.
Possible EPS Browser Errors
The following browser errors are encountered when using EPS image files:
- Corrupted file or file not found
- Windows cannot open this file
- Undefined command error or PostScript error
- Google Chrome can't display a .eps file
Advantages of EPS
The EPS file format has many advantages in the graphic design field, including:
- Embedding: The EPS files are easy to embed in other file formats or documents, including InDesign layouts, Word files, and PDFs. This makes it effortless to share illustrations and graphics with different stakeholders, namely colleagues, clients, or friends.
- Printability: EPS files are ideal for professional printing because they are simply integrated into design and layout software. EPS files also comprise vector graphics that ensure printed images are clear and crispy even when maximally scaled upwards or downwards.
- Compatibility: The EPS files are widely supported and compatible with various software, including CorelDraw, Photoshop, Inkscape, Illustrator, etc. This allows designers to choose the most appropriate tool without worrying about compatibility issues.
- Scalability: EPS files can be easily scaled upwards or downwards without losing image quality, making them suitable for sharing and creating images necessitating resizing, including illustrations and logos.
- Flexibility: The EPS files are very flexible because they can store text elements, raster, and vector graphics in a single file. This enables designers to work with multiple image elements and types without switching between file formats.
Disadvantages of EPS
The EPS file format has various drawbacks:
- Unavailable in Microsoft Office: Microsoft withdrew its support for EPS files in 2018 because of many exploits anchored on embedded PostScript usage, impacting teams and workflows that heavily depended on Office 365.
- Complexity: The EPS files use complex PostScript codes, making manual adjustments or editing of images or files difficult or challenging for most designers using the file format.
- Limited Transparency Support: The EPS files do not have inherent support for transparency, making it difficult to work with design elements or layered images that require transparent backgrounds. Designers may use SVG or PDF instead of EPS for different projects.
- Larger File Sizes: EPS files can be comparatively larger than PNG or JPEG since vector graphics need more data to describe image colors, lines, and shapes, making it difficult to work with large, complicated graphics.
How to open EPS files
EPS is a platform-independent file format that can be opened using software programs such as GIMP, GhostScript, CorelDraw, Adobe Photoshop, Adobe Illustrator, FreeHand, Irfan View, Aspose, Paint.Net, and XnView MP.
The EPS file format is compatible with most operating systems, such as Android, Unix Systems, Linux, Windows, MacOS, QuarkXPress, and iOS. However, most modern and older browsers do not support it.
Converting EPS
Individuals can use online EPS converters to transform their EPS files to raster graphics or standard image formats such as EMF, PDF, HTML, DOC, DOCX, TIFF, S BMP, VG, PNG, WMF, and JPG. An example of an online EPS converter is the "convertjack," which easily converts your file to a desired format.