(1) (
High
Data
Rate) A CDMA 3G technology. See
Qualcomm HDR.
(2) (
High
Dynamic
Range for photos) See
HDR for photos.
(3) (
High
Dynamic
Range for TV) A high dynamic range for display screens that generates more intense colors by producing blacker blacks and whiter whites. HDR is achieved by techniques within various TV brands or with TVs that support any of the HDR encoding standards added to the content.
In the TV
OLED TVs are known for their high contrast ratio; however, backlight techniques employed on LED/LCD TVs also create a high dynamic range. For example, a common method is "local dimming," in which the light is reduced to the dark pixels in real time. See
OLED,
LED TV and
Dolby HDR.
Added to the Content
HDR10, Dolby Vision and HLG are HDR encoding methods that are added to the video format. The effects are rendered on TVs that support one or more of the standards.
HDR10
HDR10 is part of the Ultra HD 4K Blu-ray standard. It supports 10-bit color, which renders 1,024 shades, one billion colors and 1,000 nits of brightness. See
nit.
Dolby Vision
Dolby Vision supports 12-bit color, which equates to 4,096 shades, 68 billion colors and 10,000 nits, although most displays cannot handle more than 4,000 nits. See
Dolby HDR.
Both HDR10 and Dolby Vision use meta-data that compliant TVs interpret but non-HDR TVs ignore. However, HDR10 meta-data affects the overall content, whereas Dolby Vision meta-data can change from scene to scene.
HLG (Hybrid Log Gamma)
Developed by the broadcast industry, HLG is the newest of the three. HLG does not use meta-data but adds a logarithmic curve to the standard dynamic range (SDR) gamma curve. HLG is compatible with old and new TVs. See
contrast ratio and
PQ.