View source for Slicing (interface design)

In fields employing interface design skills, '''slicing''' is the process of dividing a single [[2D computer graphics|2D]] [[user interface]] [[composition (visual arts)|composition]] [[page layout|layout]] ([[Comprehensive layout|comp]]) into multiple image files ([[digital asset]]s) of the [[graphical user interface]] (GUI) for one or more [[electronic page]]s. It is typically part of the [[client side]] development process of creating a web page and/or [[web site]], but is also used in the [[user interface design]] process of [[software development]] and [[game development]].

The process involves partitioning a comp in either a single layer [image file format] or the multi-layer native [[file format]] of the [[graphic art software]] used for partitioning. Once partitioned, one would save them as separate image files, typically in [[GIF]], [[JPEG]] or [[Portable Network Graphics|PNG]] format in either a [[batch processing|batch process]] or one at a time. Multi-layered image files may include multiple versions or states of the same image, often used for [[animation]]s or [[widget (computing)|widgets]].

==Practical usage==
Slicing is used in many cases where a [[graphic design]] layout must be implemented as [[interactive media]] content. Therefore, this is a very important skill set typically possessed by "[[front end processor (program)|front end]]" developers; that is interactive media developers who specialize in user interface development. 

Slices may be produced and used in several different ways. Before [[tableless web design]], sliced images were held together precisely with [[html table]]s. Modern interactive page layout includes extensive use of [[Cascading Style Sheet]]s (CSS) and [[semantic markup]]. Tables may be used for compatibility with rarer older [[web browser]]s that are incapable of processing modern tableless coding accurately.

Slicing is exclusively used for [[Raster graphics|bitmap image]]s. [[Vector graphics|Vector images]] are usually processed by [[Media player (application software)|media-playing]] [[Plug-in (computing)|plugin]] applications and contained within native [[multimedia]] file formats such as [[X3D]], [[SWF]], [[Scalable Vector Graphics|SVG]] or [[PDF]] files.

==Benefits==
Slicing reduces work loads and [[computer data storage]] space requirements to needing only the part of a dynamic image that changes instead of the whole image. If the slice is on a [[Transparency (graphic)|transparent]] multi-layered image, it can be reused in multiple parts of an image without changing the background.

On the web, slicing breaks up one large image into many smaller ones, which reduces "page weight" or [[load time]] considerably. Advanced methods of slicing can be used to further compress the amount of data needed to [[download]] to the user's computer in order for the web page to display correctly. Techniques such as repeating background images mean that one small image can be downloaded from the [[web server]] only once and then be instructed (via a CSS) to repeat by the markup language, shifting the work load from the web server onto the client's computer. Certain performance issues can be raised, however they are typically negligible compared with today's technology and trends of web design shifting towards [[rich media]] websites that typically require high [[Bandwidth (computing)|bandwidth]] connectivity and recent computing hardware.

In offline electronic media, individually sliced sections of a 2D image can be used to decrease the local computer processing requirements to change a section of that image.

==Tools==
Quite a few industry standard programs offer the abilities to automatically slice a layout directly into tables using built in functions. These are outlined below:

* [[Adobe Photoshop]]
* [[Sketch (application)|Sketch]]
* [[Adobe Fireworks]] (Previously published by [[Macromedia]])
* [[Adobe ImageReady]] (Discontinued after CS2, functionality from ImageReady ported into Photoshop since CS3)
* [[GIMP]]
* [[Jasc Paint Shop Pro]]

Recent versions of these programs have improved ability to convert artwork directly into CSS, albeit an unorthodox method since the algorithms rely heavily on [[absolute positioning]] (for example), which can render (display) inconsistently across modern web browsers.

==Alternatives==
Slicing is mainly used for [[2D computer graphics]] with single-layered interfaces. Multi-layered interfaces may use slices, but may also use [[vector graphics]] (including [[3D model]]s) with the drawback of added (most often unnoticeable) [[Rendering (computer graphics)|rendering]] time and with the advantage of more options and flexibility in altering the appearance of the individual image. These alternate individual images are commonly referred to as  [[Sprite (computer graphics)|sprites]].

==See also==
* [[Web development]]
* [[Software development]]
* [[Separation of presentation and content]]
* [[Image editing]]
* [[Graphic image development]]

==External links==
* [http://www.alistapart.com/articles/sprites alistapart.com article on CSS Sprites compared to slices]
* [http://www.xhtml-css-code.com/html/things-to-remember-while-coding-a-website-to-make-it-search-engine-friendly Things To Remember, While Coding A Website, To Make It Search Engine Friendly]
* [http://instacut.eu Slicing tool for HTML + CSS email]
* [http://wdpt.eu Tool for putting sliced images together to HTML and CSS]

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[[Category:Web design]]
[[Category:User interfaces]]
[[Category:Graphic design]]