A picture element is the smallest possible quantitative part of an image, whether it is one that is printed or a digital image on a monitor or television screen. The term is typically used with reference to graphic artwork that is printed commercially or used in graphic design. It is also commonly used with reference to monitors and displays for computer or televisions. The number of picture elements present in such a monitor is typically used to describe the quality of the monitor. A picture element is rarely considered in traditional forms of art, such as drawing or painting, though it can be of importance for certain techniques.
Also called a pixel, a picture element does not have a set size for any given medium, but is instead a term that relates to the smallest component of an image. One of the easiest ways to understand a picture element is to consider older newspaper images. These images were made up of tiny dots of ink that could be easily seen when looking closely or through a magnifying glass, similar to images created in artwork using pointillism or stippling. Each tiny dot is a picture element and was the smallest point of ink that could affordably be made at that time; pixels are smaller now as printing technology has improved.
Though the picture element count on a printed page has increased, as each dot of ink has become smaller, it is still an important consideration. Many printers, both mainstream and commercial, will advertise the dots per inch (DPI) that the printer can produce, with higher numbers representing a higher picture element count and better quality. This is because more dots in a small space are more difficult to visually discern and produce a smoother, higher quality image.
DPI can also be used with reference to video monitors and similar display devices. A picture element on a monitor is a tiny facet of the larger image. This can most easily be seen on older television screens; such screens, when viewed closely, can be seen to consist of a number of small, individual points of light that make up the larger image.
Modern displays and monitors work much the same way, though these tiny points are typically quite a bit more difficult to observe. The resolution of a computer monitor is typically given in terms of the number of picture elements available in each direction of the screen, 1024x768 indicates a monitor that is 1,024 pixels wide and 768 pixels high. Similarly, high definition televisions (HDTVs) will typically indicate the number of pixels found running the width of the screen, with higher numbers indicating greater picture quality.