Pixel

A pixel is represented by a dot or square on a computer monitor display screen. Pixels are the basic building blocks of a digital image or display and are created using geometric coordinates. Depending on the graphics card and display monitor, the quantity, size and colour combination of pixels varies and is measured in terms of the display resolution. For example, a computer with a display resolution of 1280 x 768 will produce a maximum of 98,3040 pixels on a display screen. The pixel resolution spread also determines the quality of display; more pixels per inch of monitor screen yields better image results. The physical size of a pixel varies, depending on the resolution of the display. It will equal the size of the dot pitch if the display is set to its maximum resolution, and will be larger if the resolution is lower since each pixel will use more dots. Because of that, individual pixels may become visible, leading to a blocky and chunky image defined as “pixelated”. Each pixel has a unique logical address, a size of eight bits or more and, in most high-end display devices, the ability to project millions of different colours. The colour of each pixel is determined by the specific blending of the three main components of the RGB colour spectrum. Depending on the colour system, a different number of bytes can be allocated for specifying each colour component of the pixel. For example, in 8-bit colour systems, only one byte is allocated per pixel, limiting the palette to just 256 colours. In the common 24-bit colour systems used for nearly all PC monitors and smartphone displays, three bytes are allocated, one for each colour of the RGB scale, leading to a total of 16,777,216 colour variations. A 30-bit deep colour system allocates 10 bits each of red, green, and blue for a total of 1.073 billion colour variations.