The four-byte chunk type field contains the hexadecimal values
-6D 44 43 76 +6D 44 43 56-
If present, the mDCv chunk characterizes - the Mastering Display Color Volume (mDCv) used at the point of content creation, - as specified in [[SMPTE-ST-2086]]. The mDCv chunk provides informative static metadata which +
If present, the mDCV chunk characterizes + the Mastering Display Color Volume (mDCV) used at the point of content creation, + as specified in [[SMPTE-ST-2086]]. The mDCV chunk provides informative static metadata which allows a target (consumer) display to potentially optimize its tone mapping decisions on a comparison of its inherent capabilities versus the original mastering display's capabilites.
-mDCv is typically used with the PQ [[ITU-R-BT.2100]] transfer function - and additional cLLI metadata and is commonly then called +
mDCV is typically used with the PQ [[ITU-R-BT.2100]] transfer function + and additional cLLI metadata and is commonly then called + [[?HDR10]] (PQ with ST 2086 static metadata, MaxFALL and MaxCLL). - The mDCv chunk may also be included with HLG [[ITU-R-BT.2100]] and + The mDCV chunk may also be included with HLG [[ITU-R-BT.2100]] and SDR image formats (for example [[ITU-R-BT.709]]).
-Since mDCv was originally created as supplemental static metadata meant to +
Since mDCV was originally created as supplemental static metadata meant to optimize the tone-mapping of images on a video display target, a cICP chunk - must accompany the use of mDCv in order to establish the basic characteristics + must accompany the use of mDCV in order to establish the basic characteristics of the image content. Color Primaries and White Point characteristics can be derived from cICP chunk formats. Specific examples of its most common use-cases for images using both HDR [[ITU-R-BT.2100]] and SDR [[ITU-R-BT.709]] are available in [[ITU-T-Series-H-Supplement-19]]. The basic (cICP) characteristics plus the supplemental - (mDCv) static metadata may provide valuable information to optimize + (mDCV) static metadata may provide valuable information to optimize tone-mapping decisions.
Issue #319 discusses tone-mapping behavior when - the mDCv chunk is present.
+ the mDCV chunk is present. -For SDR images, if mDCv display min/max luminance are unknown, the default +
For SDR images, if mDCV display min/max luminance are unknown, the default characteristics can be derived from the values in [[ITU-T-Series-H-Supplement-19]] Table 11 or from the relevant SDR specification. At present, there is no published, standardized method for translating an SDR image signal from its default viewing condition (display luminance and ambient illumination) to that signalled in the mDCV chunk.
@@ -3878,11 +3879,11 @@The following specifies the syntax of the mDCv chunk:
+The following specifies the syntax of the mDCV chunk:
-