IP, 4K/UHD & HDR test & measurement challenges explained Phillip Adams, Managing Director
Challenges of SDR → HDR transition
What’s to be covered o HDR – a quick overview o Compliance & monitoring challenges o Tools for test & measurement
HDR overview – more compelling, more realistic pictures BRIGHTER STRONGER GREATER WIDE COLOUR IMAGES HIGHLIGHTS CONTRAST GAMUT Outdoor Highlights, Increased Significantly scenes can be specular contrast increased noticeably reflections can colour volume brighter than be increased Detail (chromaticity) indoor scenes x100 – maintained in increases deep blacks Saturated realism colours can be brighter
Evolving HDR/WCG Standards HDR ARIB STD-B67 (HLG) Hybrid Log-Gamma ITU-R BT. 2100 (07/2016) Image (Origin BBC/NHK) parameter values for high dynamic ST2084:2014 (PQ) High Dynamic Range range television for use in Electro-Optical Transfer Function of Mastering production and international Reference Displays (origin: Dolby) programme exchange Colour Gamut ITU-R BT.709 (Parameter values for HDTV systems) ITU-R BT.2020 (Parameter values for UHDTV systems) Sony Formats S-Log3 , S-Gamut3 S-Log3-live, BT.2020 NAB 2017 - Growing interest in HDR/WCG for HD applications
HDR scales comparison Image credit: TV Technology
Wide Colour Gamut (WCG) overview Colour gamuts are abstracted into mathematical colour models & defined for use as colour spaces with finite chromaticity values The CIE 1931 colour space compares physical pure colours (i.e. wavelengths) in the electromagnetic visible spectrum and physiological perceived colours in human colour vision In ‘full HD’ television systems, BT.709 defines the colour gamut WCG refers to the colour gamut defined in BT.2020 Image credit: CEPro
Contrasting SDR/709 & HDR/2020 Image credit: Dolby
HDR/WCG overview Superior luminosity (Y-Axis) of HDR (PQ) in BT.2020, compared to SDR in BT.709 Image credit: Sony
“ A whole new set of test & measurement tools is needed to manage the wider range of brightness & broader colour space offered by HDR and WCG ”
Compliance & monitoring challenges • Managing simultaneous SDR/HDR production • Ensuring HDR levels are right for key skin & grass areas • Monitoring signal colour space after mapping to another colour space • Evolving products & standards – ensuring consistent settings across equipment • Conversion between standards is technically complex & not an exact science!
HDR / WCG New test & measurement tools for High Dynamic Range / Wide Colour Gamut
HDR test pattern generation • BT.709, BT.2020 colour space • SDR, PQ, HLG* and S-log3* • HDR patterns • SDR patterns in HDR containers • Pathological overlay • Full range of HD to UHD standards HDR enabled test pattern generator * Feature in development
HDR Heat-map tool measures luminance Programmable HDR Heat-map to highlight luminance zones Ideal for adjusting brightness of picture
HDR Heat-map tool measures luminance • 7 simultaneous and programmable colour overlay bands • Individual upper & lower overlay threshold controls • User presets for SDR & HDR modes • Selectable background grey / colour • Identify shadows, mid-tones or specular highlights
WCG: monitoring chromaticity with CIE chart • BT.709, BT.2020, DCI-P3 colour BT.2020 (WCG) gamut overlays • x, y labelled axis* BT.709 (HD) • Tooltip co-ordinate display • Picture linked cursor* • Supports SDR, PQ, HLG* and S- log3* CIE 1931 X Y chart * Feature in development
Waveform with HDR / WCG support • Graticules for SDR & HDR • YCbCr/YRGB & single trace modes • Tooltip co-ordinate display • 12-bit resolution • Horizontal / vertical pan and zoom • Picture linked cursor* • SDR, PQ, HLG* and S-log3* Waveform Display * Feature in development
Vectorscope with HDR / WCG support • Graticules/Targets for SDR and HDR* • Tooltip co-ordinate display • 12-bit resolution • Zoom to targets • User definable targets* • Picture linked cursor* • SDR, PQ, HLG* and S-log3* Vectorscope * Feature in development
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