230201 1L2L0X0A_(I), http://farbe.li.tu-berlin.de/AEAI.HTM or http://color.li.tu-berlin.de/AEAI.HTM

For this main page with general information and special images
of the corresponding image page with 10 colour series, see AEAI in English, AGAI in German.
For the previous main page, see AEZI in English, AGZI in German.
For the next main page, see AEBI in English, AGBI in German.

For links to the chapter A Colour Image Technology and Colour Management (2019), see
Content list of chapter A: AEA_I in English or AGA_I in German.
Summary of chapter A: AEA_S in English or AGA_S in German.
Example image part of 26 parts AEAS to AEZS: AEAS in English or AGAS in German.

Chapter A: Colour Image Technology and Colour Management (2019), Main part AEAI

1. Introduction and goals.

Since about 2000 the colour-information technology has developed in different directions. The ISO Committees TC 42 (Photography), TC 130 (Professional print), TC 159 (Ergonomics - Display requirement), TC 171 (Document management), and ISO/IEC SC28 (Office system) have developed many specific isolated colour standards for their devices.

In 2017, and after about 15 years the ISO Committee ISO-SCIT (Steering Committee for Image Technology) was closed. The members could not reach the goal for more common instead of isolated standards. For example the interests of industrial members are too different.

Since 2019 a new ISO guide for ISO standardization requires a balance of the net benefit of users and of industrial interests. For example ergonomic requirements are described in rules for display-work places, see ISO 9241-306. Applications of ergonomic rules for colour printers, professional print, colour cameras, and scanners can improve the net benefit and the health of all users. This is also true for the home office with display workplaces. Often a fast fatigue of users can be avoided by an ergonomic design.

2. Colour reproduction loop

The reproduction of the colour data rgb* and cmyk* of 1080 colours in the ISO file AG49 is possible after print and scan with a high precision.

Figure 1 shows the reproduction loop for this general goal.
For the download of Figure 1 in the VG-PDF format, see AEA21-4N.PDF.

In Figure 1 the abbreviation 100% Under Colour Removal (UCR) means, that all grey colours are only printed with the colorant black N, and not with three chromatic colorants C, M, and Y. If the three chromatic colorants C, M, and Y are twice as expensive as black N, then the print costs reduce with 100% UCR by up to a factor 6. In addition the important achromatic stability of the print is increased. In the case of an illuminant change a chromatic tint of the image is usually avoided.

3. ISO file AG49 according to ISO 9241-306:2018

The realisation of the colour-reproduction loop is managed with the ISO rgb*-colour file. This file is reproduced on the display and in the print by colorimetric and at the same time ergonomic criteria. A colorimetric scanner produces approximately the rgb*-colour data of the ISO-start file.

Figure 2 shows a 1MR-modification of the ISO file which is referred in Figure 1.
For the download of Figure 2 in the VG-PDF format, see AEA21-3N.PDF.

For the download of the ISO file in the VG-PDF format, see
http://standards.iso.org/iso/9241/306/ed-2/AE49/AE490-7N.PDF .

4. 1-Minus-Relation (1MR) for rgb and cmyk colour data

In Figure 2 all cmyk-colour data in this ISO file are changed by the 1-Minus-Relation (1MR) into rgb-colour data. For example it is valid:
r = 1 - c, g = 1 - m, b = 1 - y. [1]

There is software, for example Win Adobe FrameMaker V8, which does the changes according to 1MR automatically. Then the output file includes only rgb data similar as in Figure 2. The necessary second change of rgb- into cmyk-colour data is done internally by the printer manufacturers within the so called RGB printers. The intended output steering with 100% UCR is possible for proof printers in the graphical area, and with all PostScript printers A output steering by users is therefore not possible with the RGB printers in the consumer area. However, consumers request ergonomic printers with colorimetric possibilities for output steering. Methods are known and can not be applied for RGB printers.

5. Standardisation in colour-information technology: Devices and colorimetric ergonomy

Many properties of printers and displays can be tested with the standard series DIN 33872-1 to 6:2010, see

For additional ISO-test charts according to ISO/IEC 15775:1999, and ISO/IEC TR 24705:2005 see

For the ergonomic output on displays the same test charts are described according to ISO 9241-306:2018 in english, french and german with many output questions, see

Figure 3 shows the relations of many standard documents.
For the download of Figure 3 in the VG-PDF format, see EE680-3N.PDF.

Figure 4 shows the relations of many standard documents with links.
For the download of Figure 4 in the VG-PDF format, see EE681-3N.PDF.

There is free download of many of these standard documents and test charts. For a part of the German standards international standards (for example ISO/IEC DIS 19839-1 to -4) were not possible. The corresponding ISO/IEC TR 24705 was deleted in 2019.

The interests of the industry and of users are opposite, for example the industry tries to sell much colour materials. For the ergonomic output the users need usually much less colour material. A balance and steering according to the ISO net-benefit criteria seems not possible up to now.

Additional remarks and papers
Information about test charts of ISO, IEC, CEN, and DIN
according to ISO CEN 9241-306:2018 for the test of display output, and for eight contrast steps in english (E), german (G), and french (F).
The test charts are on the ISO Standards Maintenance Portal in the file formats PDF, and PostScript (PS, TXT), see

Richter, Klaus (2019), Colour Topics in the CIE and Applications, Annual conference of the German Society for Color Science (DfwG),
Leipzig, October 2019, 21 slides, 900 KB, see

Richter, Klaus (2019), Colorimetric scan, display, and print for archiving based on the ergonomic International Standard ISO 9241-306:2018 at work places, paper ARCH2019_Richter_PG_111.pdf within the book Archiving2019, Lisbon, Portugal, Society for Imaging Science and Technology.

For the application of the "anti chromatic Ostwald-Optimal colours"
see the following two reports for free download. If the first link in the standard-MLA format from the CIE web site does not work, then the second link produces the download from the WBM-archive server.

Thorstein Seim (2009), Reportership Report CIE R1-47, Hue angles of elementary colours, see (35 pages),
[ http://files.cie.co.at/526.pdf]._Internet Archive_.[ http://web.archive.org/web/20160304130704/http://files.cie.co.at/526.pdf].

Thorstein Seim (2013), Reportership Report CIE R1-57, Border between Blackish and Luminous Colours, see (23 pages),
[ http://files.cie.co.at/716_CIE%20R1-57%20Report%20Jul-13%20v.2.pdf] ._Internet Archive_.[ http://web.archive.org/web/20150413002133/http://files.cie.co.at /716_CIE%20R1-57%20Report%20Jul-13%20v.2.pdf].

Richter, Klaus (2016), Output linearization method OLM16 for displays, printers, and offset print (61 pages, 1,3 MB, Format A4) with updated links in 2019, see
The technical content of this paper is approximately equal to the Reportership Report CIE R8-09:2015. This report is freely available only for members of CIE Division 8 "Image Technology".

CIE 230:2019, Validity of formulae for prediction small colour differences, developed by CIE TC1-81 with the chairman: Richter, Klaus, see for a summary at
http://www.cie.co.at/publications /validity-formulae-predicting-small-colour-differences.

The last four papers include device independent rgb*-, cmyk*-, and Lab*-colour data for the definition of standard metadata. Standard metadata are necessary for the 1080 colours of the ISO-test chart AE49. Standard metadata are used for input linearization of scanners and cameras and the output linearization of printers and displays.

For output and input linearization in a general case 16,7 million (=256 x 256 x 256) colour data shall be changed to 16,7 million other data. With a laptop computer this is possible within less than a second.

The transformation table (Look_up_table) is calculated from the Lab*-measurement data of 729 (=9 x 9 x 9) colours in the rows 1 to 27 and the columns A to X of the test chart AE49, see K. Richter (2016).

For the archive information (2000-2009) of the BAM server "www.ps.bam.de" (2000-2018)
about colour test charts, colorimetric calculations, standards, and publications, see
indexAE.html in English, indexAG.html in German.

Back to the main page of this TUB web site (NOT archive), see index.html in English, indexDE.html in German.