What Does1080p Mean?
Digital displays consist of pixels, which are arranged in rows or lines. 1080p refers to a display that has 1,920 pixels arrayed horizontally and 1,080 pixels arrayed vertically. Said another way, the 1,920 pixels on an HD display are arranged in vertical rows crossing the screen from left to right. The 1,080 pixels are arranged in rows or lines that go from top to bottom. 1,080 (which is referred to as the horizontal resolution) is where the 1080 part of the term 1080p comes from.
The Total Number of Pixels in 1080p
With 1,920 pixels displayed across the screen and 1,080 pixels running from top to bottom, you end up with a lot of pixels. When you multiply the number of pixels across (1920) and down (1080), the total is 2,073,600. Referred to as pixel density, this is the total number of pixels displayed on the screen. In digital camera and photography terms, it’s about 2 megapixels. However, while the number of pixels remains the same regardless of the screen size, the number of pixels-per-inch changes as screen sizes change.
Where 1080p Fits In
1080p is considered quality video resolution for use in TVs and video projectors (currently 4K is higher—equivalent to 8.3 megapixels). Still, neither comes close to the megapixel resolution of many inexpensive digital still cameras. This is because it takes more bandwidth and processing power to produce moving images than still images. Currently, the maximum video resolution possible using current technology is 8K, which approaches a digital still camera resolution of 33.2 megapixels. However, it will be a few years before 8K technology becomes mainstream.
Here Comes the “p”
Now that you understand the pixel part of 1080p, what about the p? In short, the p stands for progressive. This refers to how pixel rows (or lines) display on a TV or video projection screen. When an image is progressively displayed, the pixel rows display on the screen sequentially (one after the other in numerical order).
How 1080p Relates to TVs
1080p is part of the high-definition (HD) video standards landscape. HDTVs, especially those that are 40-inches or larger, have at least a 1080p display (or pixel) resolution. However, a growing number are now 4K Ultra HD TVs. This means that if you input a signal into a 1080p TV that has a resolution of less than 1080p, the TV processes that signal so that it displays the image on its entire screen surface. This process is referred to as upscaling. This also means that input signals with less than 1080p resolution don’t look as good as a true 1080p video resolution signal because the TV has to fill in what it thinks is missing. With moving images, this can result in unwanted artifacts such as jagged edges, color bleeding, macroblocking, and pixelation (this is the case when playing those old VHS tapes). The more precise guess the TV makes, the better the image will look. The TV shouldn’t have difficulty with 1080p input signals, such as those from Blu-ray Disc and from streaming, cable, or satellite services that may offer channels in 1080p. TV broadcast signals are another matter. Although 1080p is considered Full HD, it is not officially part of the structure that TV stations use when broadcasting high-definition video signals over the air. Those signals are either 1080i (CBS, NBC, and CW), 720p (ABC), or 480i depending on what resolution the station or its associated network has adopted. Also, 4K TV broadcasting is on the way.
