There are several ways to interpolate an image. However, upscaling relies on a process called interpolation, which is really just a glorified guessing game. If you show a 1080p video on a 4K TV without upscaling, the video will take up only a quarter of the screen.įor a 1080p image to fit a 4K display, it needs to gain 6 million pixels through the upscaling process (at which point, it will become a 4K image). A 1080p TV screen is comprised of only 2,073,600 pixels, while a 4K screen has 8,294,400. It has nothing to do with the actual size of your TV.

Remember, physical resolution is defined by the number of pixels on a display. But why would you need to increase an image’s resolution? Wikipedia These algorithms effectively add pixels to an image to increase their resolution. Upscaling Makes an Image “Bigger”Įvery TV contains a mess of interpolation algorithms, which are used to upscale low-resolution images. Now that we’re all brushed up on the difference between physical and optical resolution, it’s time to get into upscaling. We’re mentioning this to reinforce the idea that screen size isn’t the same thing as physical resolution, and that a screen’s pixel density doesn’t define its physical resolution. A 4K iPhone, for example, has a higher pixel density than a 70-inch 4K TV. Pixel Density: The number of pixels per inch on a display. All 4K displays contain the same amount of pixels, but on smaller 4K displays, the pixels are closer to each other, so they have a high pixel density.Sometimes, this is a result of upscaling, but we’ll get back to that in a minute. This leads to blurry images and contrast. TVs sometimes squander their high physical resolution by displaying video with a crappy optical resolution. When a photo looks sharp and has a clear dynamic range, it has a high optical resolution. Optical Resolution: This is why your old disposable camera photos look better than your pretentious friend’s fancy digital camera photos.Physical resolution is at the mercy of optical resolution.

While TVs with a high physical resolution can use their extra pixels to offer additional detail, it doesn’t always work out that way. All 4K displays, regardless of their size, contain the same number of pixels. A 4K TV has more pixels than a 1080p TV, and a 4K image is four times the size of a 1080p image.

Physical Resolution: On a TV spec sheet, the physical resolution is simply referred to as “resolution.” It’s the number of pixels on a display.

We’re also going to cover pixel density-but don’t worry-we’ll keep things short and sweet. These aspects work together to create a good image, and they’re the basis for understanding upscaling. However, we tend to forget some key aspects, namely, the difference between physical resolution and optical resolution.

My tv is 1080p but shows 720p