The shift from analogue film to digital video has made 4K the gold standard, yet much content remains in 1080p or lower. Converting older videos to modern resolutions involves creating millions of new pixels to match the 3,840 x 2,160 pixel count of ultra-high definition. This process requires generating four times as many pixels as the original frame, a task that is nearly impossible to perform without quality loss.

Traditional upscaling software uses interpolation to estimate what missing pixels should look like. Since real detail cannot be recovered if it was never recorded, this 'guess-timation' often results in softer, smoother footage. While sharpening can help edges, it presents a delicate balance; too much processing ruins the image. Similarly, noise reduction can make final footage appear unnatural, highlighting the limitations of simple resolution changes.

For professional restorations, working from high-quality original source files is crucial. The HD restoration of Star Trek: The Next Generation illustrates this complexity. Commissioned by CBS in 2011, the project used original 35mm film negatives with quality equivalent to 20 megapixels. Over three years and more than $12 million were spent remastering all seven seasons using 25,000 reels of film stock, along with visual effects upgrades.