UHDs

UHDs, or Ultra High Definition, refers to a family of high-resolution video standards used in consumer displays and content. The term encompasses resolutions and related technologies that provide greater detail and wider color than standard high definition.

The most common UHD resolution is 3840 by 2160 pixels, marketed as UHD-1 or 4K UHD. This is the consumer counterpart to cinema 4K, which uses 4096 by 2160 pixels. A higher tier, sometimes called UHD-2, corresponds to 7680 by 4320 pixels (8K UHD). These definitions, along with color and dynamic range capabilities, are standardized in international guidance such as the ITU and ITU-T BT.2020 frameworks.

Beyond resolution, UHDs typically imply accompanying features like High Dynamic Range (HDR), which expands contrast and brightness, and a wider color gamut to improve color accuracy. Common HDR formats include HDR10, Dolby Vision, and HLG. Increased frame-rate options and improved chroma subsampling (for better color fidelity at higher resolutions) are also part of the UHD ecosystem.

Adoption and use span televisions, computer monitors, and streaming services, as well as physical media such as Ultra HD Blu-ray. Devices generally support high-bandwidth interfaces like HDMI 2.0/2.1 and may employ upscaling to render lower-resolution content at UHD levels. While UHD content requires more bandwidth and storage, advances in compression and broadband delivery have facilitated widespread distribution, contributing to the mainstream presence of UHDs in home viewing.