Computer Graphics Basics What is a pixel? Short for Picture Element, a pixel is a single point in a graphic image. Graphics monitors display pictures by dividing the display screen into thousands (or millions) of pixels, arranged in rows and columns. The pixels are so close together that they appear connected.

What is a graphic? Any kind of image displayed by a computer. Computer graphics fall under two categories: vector and raster.

Vector graphics are made up of a series of Raster graphics, also known as bitmaps, are lines, curves and splines that form different stored by the computer as a series of values, shapes through mathematical instructions. with each pixel taking a set amount of Vector graphics are resolution independent, memory. Raster graphics are resolution meaning they can be scaled to any dependent, meaning that any change in the dimension and still retain perfect resolution graphic's dimensions will result in a jagged or without affecting the graphic's file size. distorted look as well as a corresponding change in the graphic's file size. Common imaging tools for creating vector graphics are: Adobe Illustrator, CorelDraw, Common imaging tools for creating raster Macromedia FreeHand and Flash. graphics are: Adobe Photoshop, Macromedia Fireworks and Director. Vector graphics are best suited for line art, illustrations and logos. Raster graphics are best suited for photographs and continuous tone images Currently, the only widely supported vector such as blurs and drop shadows. format for use on the web is Flash. Raster graphic formats for the web are GIF, JPEG and PNG. Other raster formats such as BMP, TIF and PSD must be optimized and saved in a web format to be seen on the web.

What are the tradeoffs between vector and raster graphics? In general, vector graphics take longer to display but can be scaled to any size without any loss of image quality. Raster graphics are quick to display (especially when optimized) but image quality often becomes unacceptable when they are scaled.

There is also a tradeoff between a graphic's file size its complexity. The vector graphic file needed to draw an eight inch circle might be just a few hundred bytes while the same image as a raster graphic might be a few hundred times bigger. Conversely, the vector graphic file needed to draw a highly detailed black and white diagram in a four square inch area could easily be hundreds of times bigger than the corresponding raster graphic. So one cannot say that vector graphics are smaller than raster graphics or vice versa. It depends on the graphic.