Blog | 5 Ways the Human Eye Impacts How We Do Video Compression
--
You don’t need to know much about the human eye to use video compression standards . However, if you want to understand why they are designed the way they are, or tune your compression, knowing a little bit about the human eye goes a long way. Here are 5 facts about the human eye that directly influence our compression standards.
1. When it comes to colors, the human eye sees green best, red second best, and a little bit of blue.
Impact: Algorithms and video gear that focus on capturing green more than other colors. Humans process brightness and color differently. Because we are most sensitive to green, the way we see brightness is determined by how much green we see in something. As a result, cameras capture more green than other colors. Part of why we use green screens is because they appear so bright for people, they don’t require as much lighting compared to other choices. We also use green screens because the green channel has more information, allowing for a cleaner key around a subject. The way we process color not only impacts what the camera captures, but how we set up color encoding. We tend to create algorithms that preserve green more than the other colors, because that’s what we’re most sensitive to!
2. The highest resolution the human eye is capable of seeing is 576 megapixels.
Impact: Researchers and developers are working to create 8K TV and a codec to compress it. While your first thought might be that the 576 megapixels is a lot, it’s not the resolution we see with most of the time. That’s what you see with a very small area in the center of your eye called the fovea. The fovea only covers about 1% of the retina and you can only see about 1/60th of a degree with it. In the real world, this would be like looking at a dot about .07 inches wide from a distance of 20 feet. Most of the time the resolution you see at is between 5 and 15 megapixels. Because of this, it’s believed by many that 8K TV will be the end of the line in terms of quality. If you can’t see past this level why create it when it’s harder to capture, compress and deliver?
