The Basics

Everyone knows the basics about computer displayed images, right? Terms like pixel, polygon, and texel all sound familiar; the context surrounding these words usually offer enough information to give readers a superficial understanding. Face it, anyone can read the back of their 3D accelerator box and be able to throw these terms around without sounding like a total newbie, but how many of us know enough to give a point blank explanation of each term? What exactly is a pixel? A texel? Let's go over the basics.

Pixels and Resolutions

A pixel is the most basic unit of a computer image. A computer image is composed of a matrix of pixels, which can be represented as a matrix of bits, known as a bit map. The size of a single pixel can range from 1 bit for black and white displays to 32 bits for true color displays including the alpha bits. Pixels are the smallest addressable units for graphics which can be given a level of intensity or color.

The resolution of your display refers to number of pixels your screen is able to display. A 800 x 600 resolution displays 800 pixels in each horizontal line, and 600 pixels in each vertical column for a total of 480,000 pixels. In contrast, a higher resolution of 1600 x 1200 displays 1,920,000 pixels. Wait, does this mean that a screen with a 1600 x 1200 resolution will be 4 times bigger than a screen with an 800 x 600 resolution? No, not exactly. The size of your display will remain the same, but it will have 4 times the detail.

Let's say you have a 21 inch monitor. The size of your display will not change when you switch from 800 x 600 to 1600 x 1200, but everything will appear smaller because there will be 4 times as many pixels being displayed in the same amount of space.