Part 6/15:

For visual data, perceptual factors allow significant data reduction. Our eyes are primarily sensitive to brightness rather than color. This insight underpins schemes like chrominance subsampling: instead of transmitting full RGB values for each pixel, one can send the total brightness (Y) to all pixels and reduce the color information (UV) frequency—often to every four pixels—since the human eye can't distinguish subtle color differences at that scale. This clever exploitation of perception allows up to 50% reduction in data size without perceptible loss in quality.

The Role of Human Perception in Encoding

Perception-driven encoding is pivotal. The expert illustrates how certain color schemes and luminance levels are more critical to human observers. For example: