Digital Graphics - Curriculum 360

Digital Graphics

What are raster graphics? - Raster graphics are digital images created or captures as a set of examples of a given space. A raster is a grid of x and y coordinates on a display space. A raster image file identifies which of these coordinates to illuminate in colour values such as RGB ( Red, Green and Blue ). The raster file is sometimes referred to as a bitmap because it contains information that is directly mapped to the display grid. A raster file is usually larger than a vector graphics image file. A raster file is usually difficult to modify without loss of information, although there are software tools that can convert a raster file into a vector file, examples of a raster image file type are GIF, JPEG ( most common ), BMP and TIFF.

What are vector graphics? - Vector graphics is the creation of digital images through a sequence of commands or mathematical statements that place lines and shapes in a given two-dimensional or three-dimensional space. In physics, a vector is a representation of both a quantity and a direction at the same time. In vector graphics, the file that results from a graphic artist's work is created and saved as a sequence of vector statements. For example, instead of containing a bit in the file for each bit of a line drawing, a vector graphic file describes a series of points to be connected, one result is a much smaller file.

What are the key characteristics of both raster graphics and vector graphics? - A raster image is made of up pixels, each a different color, arranged to display an image.

A vector image is made up of paths, each with a mathematical formula (vector) that tells the path how it is shaped and what color it is bordered with or filled by. The major difference is that raster image pixels do not retain their appearance as size increases - when you blow a photograph up, it becomes blurry for this reason. Vector images do retain appearance regardless of size, since the mathematical formulas dictate how the image is rendered.

What are the most common applications of vector graphics and raster graphics? Explain why. - Right now in the present day vector graphic files such as engineering drawings are typically printed as bitmaps, after vector-to-raster conversion. The term 'vector graphics' is mainly used today in the context of two-dimensional computer graphics. It is one of several modes an artist can use to create an image on a raster display. An example of vector graphics is shown below.

Raster graphics are mostly used in photographs as it is easier to open files such as Adobe Photoshop. Most computer images are stored in raster graphics formats or compressed variations, including GIF, JPEG and PNG, which are popular on the World Wide Web.