[Openicc] ICC meta Tag for Monitor Profiles - DRAFT 1

[Kai-Uwe Behrmann]

The Draft provides means to embed monitor informations into ICC profiles.

== Introduction ==
ICC profile vendors have to maintain different installation procedures to
register ICC device profiles on a client machine. This is either fully
customised, but only for certain operating systems, or an manual error 
prone task through the required user interaction. With ICC profiles for 
monitors containing device informations, it will be easy for colour 
management systems to identify monitors and use a matching ICC profile 
without special registration in the system. This allows for easy 
preselection and implicit configuration. The advantage for vendors are 
less maintainance costs and better cross platform support in a flexible 
manner. Users benefit by the implementation of this proposal through a 
simplified and more robust colour management system. Adding of device 
informations to ICC profiles can be assisted through according tools.

This proposal defines key/value pairs for storing into a ICC display
profiles meta tag. Consequently only colour management and device
identification related properties are considered for inclusion.
A explicit configuration in a given CMS shall override such implicit
mechanisms as defined by this proposal.


==Definition==
The following key/value pairs are defined
* (key: value)
* mnft:         decoded three byte string from EDID address 8-9
* manufacturer: mapping of mnft to a full string - only for displaying
* mnft_id:      MSB decoded numerical representation of EDID address 8-9
* model_id:     LSB decoded numerical representation of EDID address 10-11
* week:         week of production from EDID address 16
* year:         decoded year of production from EDID address 17
* colour_matrix_text_from_edid_redx_redy_greenx_greeny_bluex_bluey_whitex_whitey_gamma:
containing a comma separated list of floats with decimal
point. The values are decoded from EDID address 25-34 (colour
primaries) plus address 23 (gamma)
* model:        decoded string from EDID text section 54 till 125 of 
typical type 252
* serial:       decoded string from EDID text section 54 till 125 of 
typical type 255

Detailed instructions how to decode EDID can be obtained from VESA through
the Enhanced Extended Display Identification Data Standard (E-EDID) - Rel. 
A, 1.0 .


The colour_matrix_text_from_edid_redx_redy_greenx_greeny_bluex_bluey_whitex_whitey_gamma 
keys value is composed from the according EDID block colorimetry 
informations. The values are each written as floating point as permitted 
by the ICC meta tag specifications and separated by comma. The order of 
the contained values is described by the key name itself. Parser must be 
prepared to interpret the contained values numerically and not textual.



==Example==
The data is a dump of iccDumpProfile from SampleICC
Contents of metaDataTag tag ('meta' = 6D657461)
Type:   dictType
BEGIN DICT_TAG

BEGIN DICT_ENTRY
Name=manufacturer
Value=HP
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=mnft
Value=HWP
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=model
Value=HP LP2480zx
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=serial
Value=3CM827001W
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=week
Value=27
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=year
Value=2008
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=mnft_id
Value=8944
END DICT_ENTRY

BEGIN DICT_ENTRY
Name=model_id
Value=9973
END DICT_ENTRY


BEGIN DICT_ENTRY
Name=colour_matrix_text_from_edid_redx_redy_greenx_greeny_bluex_bluey_whitex_whitey_gamma
Value=0.69043,0.296875,0.205078,0.714844,0.150391,0.0449219,0.3125,0.329102,2.2
END DICT_ENTRY

END DICT_TAG


==Discussion==
A tag to embed the complete EDID data block is defined. But that serves
different goals. Namely it is not possible to support a wider range of
devices by this approach.
To create a generic meta tag, the serial number and possibly production
times need to be stripped from the meta tag, if they are considered non
relevant in regards of colour rendering. Most monitors series will be well
identified by the model_id and mnft_id entries. Others might need the
colour_matrix_text_from_edid_redx_redy_greenx_greeny_bluex_bluey_whitex_whitey_gamma
if they can switch colour spaces.
The "week", "year", "mnft_id" and "model_id" keys might contain value
ranges as allowed by the ICC meta tag definition.



==References==
1. ICC - http://www.color.org/

2. meta tag - http://www.color.org/ICCSpecRevision_25-02-10_dictType.pdf

3. VESA - http://www.vesa.org/

4. EDID - Enhanced Extended Display Identification Data Standard (E-EDID) - Rel. A, 1.0

4.1 http://en.wikipedia.org/wiki/EDID (overview)



regards
Kai-Uwe Behrmann
-- 
developing for colour management 
www.behrmann.name + www.oyranos.org


PS: Further discussed could be the EDID CMD block. If someone would pass us a
     EDID block containing such data, that would be helpful. Thanks.