There‘s more to UHD than pixels: BBC R&D on HDR video
Tuesday, 22 July 2014
Most people associate UHD with 4K - four times as many pixels. A more important aspect is a higher range of colour and brightness - High Dynamic Range Video. Recently BBC R&D took part in the European UHD standards workshop:
Currently in stills photography, due to limitations in print and screen technologies, it is usual to utlilse a "tone-mapping" algorithm to create a lower dynamic range representation of an HDR image suitable for printing or viewing on a PC screen. These tone-mapping algorithms can lead to severe distortion and poor representation of natural scenes. For HDR video, the intent is to utilise a high brightness, high contrast ratio screen to show the HDR content, reducing the need for tone-mapping.
Their belief is that further work is required amongst the various standards groups to:
identify a suitable peak brightness and suitable dynamic range to maximise the increase in subjective quality without causing physical discomfort or requiring long adaptation periods,
identify which proposal is best suited to television including live production with mixes, fades and Digital Video Effects (DVE) image shifts, and
write a final end-to-end specification for the delivery of HDR video