In Layman’s Terms Issue 20: LCD/LED, Pixel, Megapixel, Aspect Ratio, Dithering,
With today’s issue of Layman’s Terms, we’re going to have a look at a few more graphically-inclined terms. Let’s get right into it, shall we?
LCD: “LCD” stands for “Liquid Crystal Display.” Basically, it utilizes a unique type of matter which exists somewhere between a solid and a liquid in terms of state. The molecules of this matter are particularly susceptible to electric currents, and change position based on how much voltage is applied to them. With the addition of color filters, you’ve got yourself an LCD TV or monitor. LCD’s don’t actually transmit light, so the majority of them incorporate a backlight into their design.
LED: Light Emitting Diode Displays generally use clusters of small, electrically charged diodes in addition to the standard LCD array. The diodes exist in clusters of red, blue, and green, generally, and are used as a backlight for the liquid crystal layer to allow for deeper, more vibrant colors. The color of each diode is based on the combination of electrons within the diode, as well as the size and shape of the area within the diode where the electrons can’t exist.
Pixel: Think of a picture as something of a building block. It comprises a single point within a larger image – the smallest possible unit. When a system renders an image, it does so by fitting the individual pixels together, much like you’d put together a LEGO structure. Makes sense, right?
Megapixel: This term actually has more than one meaning. The first is quite simple- it’s the next step of measurement up from the Pixel. One megapixel represents one million pixels. The second meaning is actually tied quite closely to the first, and used to measure the quality of image a camera is capable of capturing- the total pixel count of a photograph taken by a digital camera. For example, a 5MP camera will be able to capture images consisting of five million pixels. Pretty simple, right?
Granted, there’s a bit more to it than that, but for the purposes of this article…that definition will work just fine.
Aspect Ratio: The Aspect Ratio of a device refers to the height versus the width of an image. It’s typically measured in inches.
Dithering: Dithering’s a display technique by which a monitor or printer will ‘trick’ the human eye, generally by intentionally applying ‘visual noise’ to an image. A dithered image groups pixels of different colors together in a particular pattern, causing the area in which they’re grouped to appear as though it’s a single, continuous color. There’s a huge array of different dithering techniques, and I could probably write a whole article on just this entry alone. As such, we’re going to leave this one alone, for the time being.
Image Credits: [Techfresh]