A PS file or image is a vector file based on page description language (PDL), which defines the arrangement of printed pages, including the layout, graphics, and texts. PS stands for PostScript and can be identified using the .ps file extension. The file format is also called Adobe PostScript.
A PS is a vector-based file format that describes texts and images as arithmetical lines and curves rather than a series of pixels. It is ideal for generating documents requiring high-resolution scaling or printing.
Compared to vector graphic and raster graphics file formats such as ICO, WEBP, PNG, and TIFF, PS file formats can prepare digital texts and graphics for printing. It plotters precisely and accurately render graphics and texts on a specific page.
PS files or images offer sharper and more detailed information in print compared to other Page Description Languages (PDL). PS files significantly narrow the design space between Mac and PC, making them ideal for both operating systems.
History of PS Files
Adobe Systems developed the PS format in the early 1980s. However, PostScript has a rich history dating back to 1976, when Chuck Geshke and John Warnock, the co-founders of Adobe, conceptualized its ideas. Yet, in 1984, the PS was launched as a usable file format.
The file format helps create high-quality or high-resolution printouts in the printing, graphic design, and publishing industries. It defines the various elements of a printed page, such as graphics, texts, color codes, and layout. The versions of PostScript files include 1.0, 2.0, 2.1, 3.0, and 3.1.
PS was also created to make viewing and opening printed pages easier on most devices and platforms, including Unix Systems, Personal Computers, and Macs. PostScript helps print documents, necessitating high-quality outputs, such as magazines, flyers, and brochures.
Its files are device-independent, allowing printers to interpret a file's instructions and produce high-quality printouts regardless of printer resolution or model. This ensures that printouts are consistent across various printing devices, a problem previous file formats hardly addressed.
PS images are available in texts, graphics, and emails. An individual can write a text or email and send it directly to a printer without the support of other applications. The PS format specifies image elements in cubic Bezier curves and straight lines.
With the advent of direct web-enabled publishing, PostScript's most dedicated publications are less popular than they were. Nonetheless, it remains among the most intuitive graphics formats in commercial printing and is widely supported by key illustration and graphic design programs.
Properties of PS Files
The PostScript file format possesses integrated features and can handle page descriptions and interactive graphics. It comprises sampled images, texts, different color profiles, painting operators, and an arbitrary shape.
Structure
A PostScript is a vector file containing color data, page layout information, and text. The PS describes texts, images, and other elements as mathematical lines and curves rather than a pool of pixels. It does not permit multi-sample pixels.
The PS file format structure includes a header, color mode data, image data, mask, and layer information, alongside other information or elements. The PostScript header contains information concerning the PS file, including the resolution, version number, and type.
It allows printing resolutions of 300 or 600 pixels per inch, making it a high-resolution file format. The PS's high resolution makes its images more detailed and sharp during and after printing. However, users can also opt for low-resolution printing to allow large images to be viewed from a distance.
Low-resolution PS images are used in highway billboards. Conversely, the color mode data comprises information regarding color depth and color mode. PS files support CIE, CMYK, RGB, and grayscale colors.
Particular types of colors are modeled as varying features, namely repeating patterns, shading, color mapping, and spot colors. Specifically, the default PS mode is grayscale output at a depth of 4-bit per pixel channel for each of the three colors. Other available PostScript depths include 1-bit, 2-bit, 4-bit, and 8-bit per pixel.
Its output quality varies considerably based on the number of bits used. Nonetheless, Monochrome PS files also support grayscale. PS drivers support monochrome or color PostScript devices as a scripting language. Monochrome is the default color feature.
It contains high-quality images, although it uses varying data representations compared to raster image files. PostScript is a scripting language rather than a file format. A PostScript file has a size limit of 30,000x30,000 pixels. No PS file or image can exceed 4GB, irrespective of the storage space available.
The image data contains the actual file or image data in either a vector or raster graphics format. It specifies images using geometry information such as commands instead of individual pixels. PS allows geometrical specifications to be printed at the maximum number of details possible.
The PostScript file also contains information about its mask and layers. Finally, the file format's structure includes information on manuscripts, like clipping paths, guides, and notes. The specifications of PS files make them complex for conversion and may lead to quality degradation.
Storage
PostScript stores data as prearranged layouts, graphics, and texts. It sends ongoing data on an hourly basis to a data warehouse. Historical data are pushed to a data warehouse upon the initial push. PostScript vector graphics data, including literals, logos, illustrations, and diagrams, is stored and transmitted uncompressed.
The pushed data document can contain compressed image data and the decompression routine needed to handle it. Thus, PostScript allows data to be stored indefinitely in file systems, the cloud, hard drives, or other memory drives.
Compression
PS files are an uncompressed file format. They do not need compression, either lossy or lossless. PostScript is a scripting language that controls the use of É…B and Run Length Encoding compression. Users do not need to configure the plotter to use any compression method.
Since PostScript files are uncompressed, they are larger and necessitate more storage space for retouches and photographers. The larger file sizes of PS files result in slow web responsiveness or increased web loading time.
Editing
Adobe Photoshop is the most popular software for creating PS files. Additional popular tools for creating and editing PS files include Adobe Illustrator, Photoshop, Adobe InDesign, CorelDraw, and GIMP.
The psresize command can resize a PostScript file or image. It scales to any required dimensions without losing image quality.
The scripting language files can be resized using software or programs such as VLC, IrfanView, Inkscape, CorelDraw, Adobe Photoshop, Microsoft Paint, Adobe Illustrator, Adobe Acrobat, and GIMP.
Animation
PostScript (PS) does not support animation. It is designed for static content and lacks multimedia and interactivity capabilities that support images or files compared with PDF or HTML. PostScript files are intended for printing, making them unsuitable for screen-based content.
Transparency
PostScript (PS) files do not support transparency when printing vector graphics images. Nonetheless, partially transparent or translucent images can be rendered as fully opaque and transparent pixels. Translucent PS images are known as masks.
Best Use Case of PS Files
- Suitable for graphic design projects, including print layouts, illustrations, and logos
- Suitable for generating professional documents such as reports, letters, and resumes
- Suitable for image editing activities, namely color correction, resizing, and cropping
- Suitable for photo manipulation like adding special effects, airbrushing, and retouching
- Suitable for vector illustration in comic art, icons, and creating company logos
- Suitable for printing, including commercial offset printing and desktop printing
Unrecommend Use Cases of PS Files
- Unsuitable for storing multiple files in limited storage space because they are large.
- Unsuitable for customizing reversible compressed files because of its limited editing capabilities
- Unsuitable for screen-based content such as animation or lively content
PS Browser Support
Web browsers do not directly support PostScript. However, users can add PostScript Compiler and Viewer to their browsers to open PostScript files in Google Chrome.
PostScript is not widely supported by top desktop and mobile browsers such as:
- Apple’s Safari
- Opera Mini
- Mozilla Firefox
- Vivaldi
- Microsoft Edge
- Internet Explorer
- Brave
- Discord
Possible PS Browser Errors
- Device communication error
- File not found
- Paper Out or paper jam error
- Timeout or Timeout Error
- Syntax Error or Invalid Operand
- Windows cannot open this file
- Limit check or Limitcheck Offending Command
- Printer offline or print spooler error
- Printer firmware error
- VMerror: dictfull
- Undefined command error or PostScript error
Advantages of PS
- Device Independent: The PostScript file format allows output quality to be consistently high when printing on a professional setup or in the home office.
- High-Quality: The PostScript file format produces detailed and sharper printouts than other page description languages (PDLs) used in printing.
- Design Gap Reduction: PostScript files minimize the design gap between Mac and Personal Computers as they can be used in both operating systems.
- Compatible: PostScript files are highly compatible and supported by various software programs, platforms, and devices.
- High Resolution: PostScript files can be printed at 300 or 600 pixels per color channel.
Disadvantages of PS
- Larger File Sizes: PostScript files retain detailed image data, making them larger and slower during transmission
- Lacks Universal Support: Whereas a select niche of print aficionados still uses PS files, most current software programs hardly support the file format.
- Inefficient Conversion: Though most printers support PostScript, not every model converts its files efficiently
How to open PS files
Adobe Photoshop is the most commonly used software for opening and editing PS files. Other programs which can be used to open PS files include GIMP, Amiga Forever, Acrobat, VLC, Photoshop, Works, Corel Paintshop Pro, and Adobe Fireworks.
On the other hand, a PostScript (PS) file is compatible with and supported by operating systems such as MacOS, Windows, Android, Linux, OS/2, and Unix Systems.
PS files are incompatible with most image editing or opening software, such as Okular, Inkscape, ImageMagick, and GostView. However, these programs need additional plug-ins or supporting software to open PS files.
Converting PS Images to other formats
Online PS converters can convert such files to PDF, SVG, BMP, PPM, EPS, PNG, JPEG, TIFF, GIF, and HEIC. You can use “convertjack†to convert a PostScript-generated file to the required format.