210810 1L2L0X0A_(I), http://farbe.li.tu-berlin.de/AEAI.HTM oder http://color.li.tu-berlin.de/AEAI.HTM
Back to the TUB-main page (NOT archive), see index.html in English, indexDE.html. in German
For the archive information of the BAM-Server (2000-2017)
"http://www.ps.bam.de", see A/indexAE.html in English, A/indexAG.html in German

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 the corresponding image page with 10 colour series, see
AEAS in English, AGAS in German.
For the previous image page, see AEZS in English, AGZS in German.
For the next image page, see AEBS in English, AGBS in German.

For links to the chapter A Colour Image Technology and Colour Management, 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 content part AEAI of 26 parts AEAI to AEZI: AEAI in English or AGAI in German.
Example images part AEAS of 26 parts AEAS to AEZS: AEAS in English or AGAS in German.

For links to the chapter B Colour Vision and Colorimetry, see
Content list of chapter B: BEA_I in English or BGA_I in German.
Summary of chapter B: BEA_S in English or BGA_S in German.
Example content part BEAI of 26 parts BEAI to BEZI: BEAI in English or BGAI in German.
Example images part BEAS of 26 parts BEAS to BEZS: BEAS in English or BGAS in German.

For links to the chapter C Colour Spaces, Colour Differences, and Line Elements, under work, see
Content list of chapter C: CEA_I in English or CGA_I in German.
Summary of chapter C: CEA_S in English or CGA_S in German.
Example content part CEAI of 26 parts CEAI to CEZI: CEAI in English or CGAI in German.
Example images part CEAS of 26 parts CEAS to CEZS: CEAS in English or CGAS in German.

For links to the chapter D Colour Appearance, Elementary Colours, and Metrics, under work, see
Content list of chapter D: DEA_I in English or DGA_I in German.
Summary of chapter D: DEA_S in English or DGA_S in German.
Example content part DEAI of 26 parts DEAI to DEZI: DEAI in English or DGAI in German.
Example images part DEAS of 26 parts DEAS to DEZS: DEAS in English or DGAS in German.

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

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
http://farbe.li.tu-berlin.de/A/33872E.html.

For additional ISO-test charts according to ISO/IEC 15775:1999, and ISO/IEC TR 24705:2005 see
http://farbe.li.tu-berlin.de/A/24705TE.html.

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
http://standards.iso.org/iso/9241/306/ed-2/index.html.

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