To be able to display lower resolution images and video on high-resolution screens TVs perform a function called upscaling.
Unfortunately, there are two main issues with this approach.
The real way upscaling works is by performing analysis with an interpolation algorithm.
The interpolation algorithm works by interpreting the image as is at the higher resolution.
This generally involves the machine having to infer what the colours would be between multiple pixels.
The difficulty comes with inferring the pixel colour when there is a colour gradient.
A sharpening algorithm is also used to help improve the clarity of the image.
Upscaling is almost always performed when the content is played, generally by the TV or other playback gear.
Upscaling can only be taken so far.
