Computer Graphics

Graphical Design and Computers

Computer graphics are graphics created by computers and, more generally, the representation and manipulation of pictorial data by a computer. The term computer graphics includes almost everything on computers that is not text or sound. Today nearly all computers use some graphics and users expect to control their computer through icons and pictures rather than just by typing. The term Computer Graphics has several meanings:

• the representationand manipulationof pictorialdataby a computer
• the various technologiesused to create and manipulate such pictorial data
• the imagesso produced, and
• the sub-field of computer sciencewhich studies methods for digitally synthesizing and manipulating visual content.

Today computers and computer-generated images touch many aspects of our daily life. Computer imagery is found on television, in newspapers, in weather reports, and during surgical procedures. A well-constructed graph can present complex statistics in a form that is easier to understand and interpret. Such graphs are used to illustrate papers, reports, theses, and other presentation material. A range of tools and facilities are available to enable users to visualise their data, and computer graphics are used in many disciplines.

Types of Computer Graphics

2D computer graphics

2D computer graphics are the computer-based generation of digital images—mostly from two-dimensional models, such as 2D geometric models, text, and digital images, and by techniques specific to them. The word may stand for the branch of computer science that comprises such techniques, or for the models themselves.

2D computer graphics are mainly used in applications that were originally developed upon traditional printing and drawing technologies, such as typography, cartography, technical drawing, advertising, etc.. In those applications, the two-dimensional image is not just a representation of a real-world object, but an independent artifact with added semantic value; two-dimensional models are therefore preferred, because they give more direct control of the image than 3D computer graphics, whose approach is more akin to photography than to typography.

Pixel art

Pixel art is a form of digital art, created through the use of raster graphics software, where images are edited on the pixel level. Graphics in most old (or relatively limited) computer and video games, graphing calculator games, and many mobile phone games are mostly pixel art.

Vector graphics

Vector graphics formats are complementary to raster graphics, which is the representation of images as an array of pixels, as it is typically used for the representation of photographic images. There are instances when working with vector tools and formats is best practice, and instances when working with raster tools and formats is best practice. There are times when both formats come together. An understanding of the advantages and limitations of each technology and the relationship between them is most likely to result in efficient and effective use of tools.

3D computer graphics

3D computer graphics in contrast to 2D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images. Such images may be for later display or for real-time viewing.

Despite these differences, 3D computer graphics rely on many of the same algorithms as 2D computer vector graphics in the wire frame model and 2D computer raster graphics in the final rendered display. In computer graphics software, the distinction between 2D and 3D is occasionally blurred; 2D applications may use 3D techniques to achieve effects such as lighting, and primarily 3D may use 2D rendering techniques.

3D computer graphics are often referred to as 3D models. Apart from the rendered graphic, the model is contained within the graphical data file. However, there are differences. A 3D model is the mathematical representation of any three-dimensional object (either inanimate or living). A model is not technically a graphic until it is visually displayed. Due to 3D printing, 3D models are not confined to virtual space. A model can be displayed visually as a two-dimensional image through a process called 3D rendering, or used in non-graphical computer simulations and calculations.

Computer animation

Computer animation is the art of creating moving images via the use of computers. It is a subfield of computer graphics and animation. Increasingly it is created by means of 3D computer graphics, though 2D computer graphics are still widely used for stylistic, low bandwidth, and faster real-time rendering needs. Sometimes the target of the animation is the computer itself, but sometimes the target is another medium, such as film. It is also referred to as CGI (Computer-generated imagery or computer-generated imaging), especially when used in films.

To create the illusion of movement, an image is displayed on the computer screen then quickly replaced by a new image that is similar to the previous image, but shifted slightly. This technique is identical to the illusion of movement in television and motion pictures.

Computer Graphic Programs

Adobe™ Photoshop

Adobe Photoshop, or simply Photoshop, is a graphics editing program developed and published by Adobe Systems. It is the current and primary market leader for commercial bitmap and image manipulation, and is the flagship product of Adobe Systems. It has been described as an industry standard for graphics professionals.

Photoshop CS4, the current eleventh iteration of the program, was officially announced on 23 September 2008. "CS" reflects its integration with other Creative Suite products, and the number "4" represents it as the fourth version released since Adobe re-branded its products under the CS umbrella. Photoshop CS4 features additions such as the ability to paint directly on 3D models, wrap 2D images around 3D shapes, convert gradient maps to 3D objects, add depth to layers and text, get print-quality output with the new ray-tracing rendering engine, and enjoy exporting to supported common 3D formats; the new Adjustment and Mask Panels; Content-aware scaling (previously known as seam carving); Fluid Canvas Rotation and File display options. On 30 April, Adobe released Photoshop CS3 Extended, which includes all the same features of Adobe Photoshop CS3 with the addition of capabilities for scientific imaging, 3D, and high end film and video users. The successor to Photoshop CS3, Photoshop CS4, will be the first 64-bit Photoshop on consumer computers.

GIMP

The GNU Image Manipulation Program, or GIMP, is a free raster graphics editor used to process digital graphics and photographs. Typical uses include creating graphics and logos, resizing and cropping photos, altering colors, combining multiple images, removing unwanted image features, and converting between different image formats. GIMP can also be used to create basic animated images in GIF format. It is often used as a free software replacement for Adobe Photoshop, the most widely used bitmap editor in the printing and graphics industries; however, it is not designed to be a Photoshop clone. The project's mascot is named Wilber.

The project was started in 1995 by Spencer Kimball and Peter Mattis and is now maintained by a group of volunteers under the auspices of the GNOME Project. The current version of GIMP works with numerous operating systems, including all modern Linux distributions, all recent versions of Microsoft Windows, and Apple's Mac OS X.

Corel Paint Shop Pro

Paint Shop Pro (PSP) is a raster graphics editor and, later in the series, a vector graphics editor for computers running the Microsoft Windows operating system that was originally published by Minneapolis-based Jasc Software. In October 2004, Corel Corporation purchased Jasc Software and the distribution rights to Paint Shop Pro. PSP functionality can be extended by Photoshop-compatible plugins. They are listed in the 'Effects' menu, below the built-in effects.

Originally called simply Paint Shop, the first version, 1.0, was released in early 1992. Paint Shop was originally distributed as shareware and is still available at many download sites (4.12 being a popular version). Newer versions are only available commercially. A key competitor is Adobe Photoshop, the commercial market leader in this category. Photoshop’s popularity is in part because Photoshop is available in an Apple Macintosh version, the platform widely used in the print publication industry, whereas Paint Shop Pro only runs on Microsoft platforms. While Photoshop is a popular piece of editing software, PSP is also widely used due to the lower price, and it was frequently called the "poor man's Photoshop." Corel announced, on November 28, 2007, that the office that created Paint Shop Pro would be shut down with development moved to offices in California and Taiwan.

Ulead PhotoImpact

Ulead PhotoImpact is a series of imaging software created by Ulead Systems. PhotoImpact is a powerful vector based graphics suite suitable for the home user as well as the digital artist. Considered to be especially useful for designing Web Graphics, Ulead has incorporated several HTML tools, such as rollover assistant, imagemap assistant, HTML assistant, background designer and button library. Photo editing is a breeze with retouch tools, red eye removals, and hundreds of masks and textures to liven up your Digital images. The current version of Photoimpact is Version X3.