This is one of a series of articles. If you are interested in other articles in this series, they are as follows:
Part 3 of this series addressed the overall issues of naming conventions defined by the various organizations (DCI, ITU, EBU and CEA) regarding 4K and Ultra-HDTV.
This part 4 covers the specifics of the DCI (Digital Cinema Initiatives) and ITU (International Telecommunications Union) naming conventions and standards.
Part 5 will cover European Broadcasting Union (EBU) and the Consumer Electronics Association (CEA) naming conventions and standards, wrap the subject, and provide a historic perspective of similar naming decisions made by the CEA with DTV.
Digital Cinema Initiatives (DCI) 4K standard:
And I quote from the standard document:
"A joint project of seven motion picture studios (Disney, Fox, MGM, Paramount, Sony Pictures Entertainment, Universal, and Warner Bros.), DCI published their specification in 2005....The primary purpose of DCI is to establish uniform specifications for Digital Cinema.."
"The Digital Cinema system shall have the capability to present a theatrical experience that is better than what one could achieve now with a traditional 35mm Answer Print."
"The specification calls for picture encoding using the ISO/IEC 15444-1 "JPEG2000" (.jp2) standard and use of the CIE XYZ color space at 12 bits per component encoded with a 2.6 gamma applied at projection, and audio using the "Broadcast Wave" (.wav) format at 24 bits and 48 kHz or 96 kHz sampling, controlled by an XML-format Composition Playlist, into an MXF-compliant file at a maximum data rate of 250 Mbit/s."
DCI Formats: 2K and 4K. K means 1024 pixels of horizontal resolution.
2K Format: 2048x1080
4K Format: 4096x2160
Aspect Ratio: 1.89 (17:9)
Color Space: 12-bit each per X'Y'Z' channel using the most significant bits of 16-bit words (filled with 4 zeros)
Audio: capacity for up to 16 channels of uncompressed audio at 24 (AES3) bits at 48 kHz or 96 kHz sampling rates, with subtitles. The presentation is required to provide, at a minimum, a 5.1 audio format, (Left, Center, Right, Low Frequency Effects, Left Surround and Right Surround).
Frame Speed: 2K: could be 24fps or 48fps (12-bit DCDM), 4K could be 24fps only
Spatial Resolution Conversion (as per DCI standard): "The projector is required to display either a native resolution of 4096x2160 or 2048x1080. If the projector's native resolution is 4096x2160, and the incoming spatial resolution of the content is 2048x1080, then the projection system is required to perform the up-conversion of 2048x1080 content to 4096x2160. All spatial conversions are required to be done at an exact ratio of 2:1 in each axis, i.e., a projector with a horizontal pixel count of slightly higher than the image container is required to not convert the projected image beyond the image container to fill the array, nor is an image to be converted to something less than the 4096x2160 or 2048x1080 image container size.
Should electronic image resizing or scaling be used to support a constant height projection or constant width projection theater environment, then it is required that the image resizing or scaling does not introduce visible image artifacts."
Ultra-HDTV as defined by the ITU (International Telecommunication Union):
As per ITU-R BT.2020 UHDTV parameters document (August 2012)
Picture aspect ratio: 16x9
Quantization Levels: 10 and 12 bit per component
Frame frequencies (Hz): 24, 30, 60, and (updated to) 120 fps, and also 25 and 50 for other systems/countries.
Scan mode: progressive
Resolutions: 3840x2160 and 7680x4320, also called as 4K and 8K by ITU:
“The first level of UHDTV picture levels has the equivalent of about 8 megapixels (3840 x 2160 image system), and the next level comes with the equivalent of about 32 megapixels (7680 x 4320 image system). As a shorthand way of describing them, they are sometimes called the ‘4K’ and ‘8K’ UHDTV systems.”
Recommended diagonal minimum size of screens: 1.5 meters and larger screens (LSDI) of large venue presentations to "provide viewers with an increased sense of “being there” and increased sense of realness" and "higher spatial/temporal resolution, wider colour gamut, wider dynamic range, etc."
Recommended viewing distance for 8K: 0.75 H
Diagram of the CIE 1931 color space that shows the Rec. 2020 (UHDTV) color space in the outer triangle and Rec. 709 (HDTV) color space in the inner triangle. Both Rec. 2020 and Rec. 709 use Illuminant D65 for the white point.
Ultra-HDTV Audio as per ITU:
22.2 multichannel sound with audio sampling frequency of 48 kHz, and 96 kHz, which can optionally be applied, with a bit depth of 16 bits, 20 bits or 24 bits per audio sample.
1 FL Front left
2 FR Front right
3 FC Front centre
4 LFE1 LFE-1
5 BL Back left
6 BR Back right
7 FLc Front left centre
8 FRc Front right centre
9 BC Back centre
10 LFE2 LFE-2
11 SiL Side left
12 SiR Side right
13 TpFL Top front left
14 TpFR Top front right
15 TpFC Top front centre
16 TpC Top centre
17 TpBL Top back left
18 TpBR Top back right
19 TpSiL Top side left
20 TpSiR Top side right
21 TpBC Top back centre
22 BtFC Bottom front centre
23 BtFL Bottom front left
24 BtFR Bottom front right
Stay tuned for part 5 of this “Living with 4K” series for the European Broadcasting Union (EBU) and the Consumer Electronics Association (CEA) naming conventions and standards for U-HDTV and U-HD.
Posted by Rodolfo La Maestra, December 21, 2012 7:24 AM
About Rodolfo La Maestra
Rodolfo La Maestra is the Senior Technical Director of UHDTV Magazine and HDTV Magazine and participated in the HDTV vision since the late 1980's. In the late 1990's, he began tracking and reviewing HDTV consumer equipment, and authored the annual HDTV Technology Review report, tutorials, and educative articles for HDTV Magazine, DVDetc and HDTVetc magazines, Veritas et Visus Newsletter, Display Search, and served as technical consultant/editor for the "Reference Guide" and the "HDTV Glossary of Terms" for HDTVetc and HDTV Magazines. In 2004, he began recording a weekly HDTV technology program for MD Cable television, which by 2006 reached the rating of second most viewed.
Rodolfo's background encompasses Electronic Engineering, Computer Science, and Audio and Video Electronics, with over 4,700 hours of professional training, a BS in Computer and Information Systems, and thirty+ professional and post-graduate certifications, some from MIT, American, and George Washington Universities. Rodolfo was also Computer Science professor in five institutions between 1966-1973 in Argentina, regarding IBM, Burroughs, and Honeywell mainframe computers. After 38 years of computer systems career, Rodolfo retired in 2003 as Chief of Systems Development from the Inter-American Development Bank directing sixty+ software-development computer professionals, supporting member countries in north/central/south America.