230201 1L2L0X0A_(I), http://farbe.li.tu-berlin.de/AEDI.HTM or http://color.li.tu-berlin.de/AEDI.HTM
For this main page with general information and special images
of the corresponding image page with 10 colour series, see
AEDI in English,
AGDI in German.
For the previous main page, see
AECI in English,
AGCI in German.
For the next main page, see
AEEI in English,
AGEI 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 AEDI
1. Introduction and goals.In the main part AEBI the ISO-test charts AE49, AE09, and AE19 were changed from the vector-graphic format VG-PDF to the pixel-graphic format PG-PDF. The PG-PDF files have essential disadvantages and rarely advantages compared to the VG-PDF files:
- PG-PDF files are often by a factor 100 larger.
- the pixel structure of PG-PDF files is visible and disturbing with increasing magnification.
In this part the ISO-test charts AE09, AE19, AE29, AE39, and AE49 of the vector-graphic format VG-PDF are changed to a vector-graphic format VG-PDF with different content.
In addition to the PS-Operator settransfer the ISO-test charts use the three PS operators setgray, setrgbcolor und setcmykcolor. The 16 million possible colour data of these PS operators w, rgb und cmyk shall often be transferred into 16 million other data.
With the 1-minus-relation (1MR) the colour data w and cmyk are transferred into rgb colour data. Then only 16 million possible rgb colour data shall be transferred into 16 million other data. This produces many advantages:
- The produced VG-PDF files have for all 15 ISO-contrast steps the same and often by a factor 100 smaler size compared to the PG-PDF files.
- the output of the VG-PDF files can be magnified by a factor 16. A pixel structure is not visible. This leads to optimal readability and recognition.
The 16 million possible rgb colour data shall be transferred often into 16 millionen other data.
In case of PG-PDF files only the rgb colour data of settransfer shall be transferred. This is an advantages of PG-PDF files.
In case of VG-PDF files the 1MR calculation shall be done. Then only rgb colour data of setrgbcolor shall be transferred.
In this part from the standard ISO-contrast step CYP8 the other 15 ISO-contrast steps CYP1 to CYP15 are produced. For this no new file is produced with new calculated colour data.
The output of the VG-PDF file ist based on operators of the programming language PostScript. Additional PS procedures with mathematical transformations are for the steering of the output
- included in a PS file or
- included in a frame file or
- copied in the PS-AdobeDistillerDirectory.
In the last two cases the output of many files may be steered, for example a book with many pages.
2. Contrast change of test chart ISO-AE29 and ISO-AE39 in the VG-PDF format in 15 steps.
The following figures 1 to 6 use a frame file in the VG-PDF format with 16 separate figures.
All chromatic and achromatic figures are in the VG-PDF format. The file size is extremely small,
and any figure can be magnified by a factor 16 without any resolution defect.
Another main part AGBI includes similar figures as the figures 3 to 6.
In the part AGBI any frame files is also in the VG-PDF format. However, all chromatic figures
in AGBI are in the PG-PDF format. The figure-file size in the PG-PDF format is often by a factor 100 larger
compared to the VG-PDF format. It is often disturbing, that the pixel structure is visible for
any magnification. In the case of PG-PDF files a change of the ISO-contrast step requires only
a change of the PS operator settransfer.
The figures 1 to 6 use VG-PDF files. They require a more complex change of the data of the three
PS operators setrgbcolor, setcmykcolor, and setgray.
This way has the advantage that the file size still remains extremely small.
In addition with magnification no resolution defects occur.
The display contrast changes with the reflection of the environmental light on the display.
One can study in the following the visual changes of the achromatic ISO-test chart AE29,
and of the chromatic ISO-test chart AE39.
Figure 1 shows the ISO-test chart AE29 for 5 of 15 ISO-contrast steps.
For the download of this figure in the VG-PDF format, see
AED0L0N1.PDF.
Visual results show, that the optimal output of AE29 with 16 approximately
equidistant grey steps produces also 16 equidistant chromatic steps,
for example between white and the device cyanblue Cd or magentared Md or yellow Yd.
However, for the visibility of the element Landolt-ring a little lower contrast step
seems to be often better, for example by the ISO-contrast step CYP3 instead
of the step CYP5 in the standard office.
Figure 2 shows the ISO-test chart AE39 for 5 of 15 ISO-contrast steps.
For the download of this figure in the VG-PDF format, see
AED2L0N1.PDF.
With many output questions on 24 pages the ISO-test charts AE29 and AE39
can be downloaded. The ISO-test charts are similar to figure 1 and 2.
AE29: For the 8 ISO-contrast steps CYP1=CYN15 to CYP8=CYN8
on 24 pages, see (2,2 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE29/AE29F0PX.PDF
AE29: For the 8 ISO-contrast steps CYN8=CYP8 to CYN1=CYP15
on 24 pages, see (2,2 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE29/AE29F0NX.PDF
AE39: For the 8 ISO-contrast steps CYP1=CYN15 to CYP8=CYN8
on 24 pages, see (2,4 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE39/AE39F0PX.PDF
AE39: For the 8 ISO-contrast steps CYN8=CYP8 to CYN1=CYP15
on 24 pages, see (2,4 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE39/AE39F0NX.PDF
The ISO-test chart AE28 has in addition to AE29 an ISO/IEC image "flower motif".
Properties of this image are described in the main part AEEI.
3. Contrast change of ISO-AE49 with 1080 colours in the PG-PDF format in 15 steps.
The display contrast changes with the refection of the environment light on the display.
In the standard office with daylight the display contrast also changes with the day time.
Therefore defined changes of the gamma values gP are necessary to remain the health
of the users. This often avoids a fatigue or an overstress of the visual system.
Figure 3 shows on the top left the standard display output for the ISO-contrast step
CYP8.
For the download of this Figure in the VG-PDF format, see
AED3L0N1.PDF.
Figure 3 shows the ISO contrast steps CYP8 (position 0-1), CYP1 (position 0-2),
CYP5 (position 0-5), CYP6 (position 0-6), CYP8 (position 1-1), and
CYP15 (position 1-8). The contrast step CYP8 at the positions
0-1 and 1-1 is identical. This is the standard contrast in a dark room without any reflection
on the display. This case is marked by a red continuous square.
The standard display according to ISO 9241-306 has the contrast step CYP5.
This case is marked by a red dashed square. For this case the rgb data shall be changed
by the formulae in figure 1 with the exponent n = gP = 0,775.
IEC 61966-2-1 (sRGB-colour space) defines the
absolute gamma with ga = 2,4. The Mac computer-operating system has used
for more than 20
years until 2017 the absolute gamma ga = 1,8 as default value. The value ga = 1,8
corresponds to the relative gamma gP = 1,8/2,4 = 0,75. This is approximately the
required value gP = 0,775 for CYP5 (standard office)
according to ISO 9241-306.
In 2017 the value of the Mac gamma ga = 1,8 was changed to 2,4
and adjusted to the Windows gamma ga = 2,4.
This value corresponds to the relative gamma gP = 1,0. However, now in this point
the ergonomic requirements for the display output according to ISO 9241-306 are NOT any more
fulfilled for both operating systems.
If in the application many grey and colour steps are important for the display output, then
this ergonomic failure according to ISO 9241-306 leads to a fatigue and an overstress
of the visual system.
Until 2018 on the Mac operating system OSX and in agreement with the first edition of
ISO 9241-306:2009 a slider has allowed to change the gamma. With this slider it was possible
to adjust the whole display output and not only a file output according to the display contrast.
The first and second edition of ISO 9241-306 describes this possibility.
However in 2019 this possibility under "System Preferences - Display - Color - Gamma" was
deleted. Since 2019 the slider "Gamma" is not any more available.
Therefore now under the computer operating systems Mac, Windows, and Unix
one must look for corresponding possibilities, to fulfill the ergonomic standard
ISO 9241-306.
Figure 4 shows on the top left the ISO-contrast step CYP8 and for the steps CYP1
to CYP15
For the download of this Figure in the VG-PDF format, see
AED5L0N1.PDF.
Figure 4 shows den contrast step CYP8 (Position 0-1) and CYP1 (Position 0-2) to
CYP15 (Position 1-8). The contrast step CYP8 on the positions 0-1 and 1-1 is identical.
This is the standard contrast step in a dark room. This standard contrast step according to IEC 61966-2-1
is marked by a red continuous rectangle. The ergonomic standard contrast step CYP5 according to
ISO 9241-306 is marked by a red dashed rectangle.
With many output questions on 24 pages the ISO-test chart AE49 can be downloaded from an
ISO server. This ISO-test chart is on every third page similar to figure 4 and 5 for the eight contrast
step CYP1 to CYP8.
The page AE49 can be reached from the main ISO page
http://standards.iso.org/iso/9241/306/ed-2/index.html
AE49: For the 8 ISO-contrast steps CYP1=CYN15 to CYP8=CYN8
on 24 pages, see (1,7 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE49/AE49F0PX.PDF
AE49: For the 8 ISO-contrast steps CYN8=CYP8 to CYN1=CYP15
on 24 pages, see (1,8 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE49/AE49F0NX.PDF
4. Contrast change of test chart ISO-AE09 and ISO-AE19 in the PG-PDF format in 15 steps.
The display contrast changes with the reflection of the environmental light on the display.
One can study the visual changes on the achromatic ISO-test chart AE09,
and the chromatic ISO-test chart AE19.
Figure 5 shows the ISO-test chart AE09 for 5 of 15 ISO-contrast steps.
For the download of this figure in the VG-PDF format, see
AED6L0N1.PDF.
Visual results show, that the optimal output of AE09 with 16 approximately
equidistant grey steps produces also 16 equidistant chromatic steps,
for example between white and device red Rd or green Gd or blue Bd.
However, for the visibility of the element Landolt-ring a little lower contrast step
seems to be often better, for example CYP3 instead of CYP5 in the standard office.
.
Figure 6 shows the ISO-test chart AE19 for 5 of 15 ISO-contrast steps.
For the download of this figure in the VG-PDF format, see
AED8L0N1.PDF.
With many output questions on 24 pages the ISO-test charts AE09 and AE19
can be downloaded. The ISO-test charts are similar to figure 5 and 6 for the contrast step
CYP8.
AE09: For the 8 ISO-contrast steps CYP1=CYN15 to CYP8=CYN8
on 24 pages, see (2,2 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE09/AE09F0PX.PDF
AE09: For the 8 ISO-contrast steps CYN8=CYP8 to CYN1=CYP15
on 24 pages, see (2,2 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE09/AE09F0NX.PDF
AE19: For the 8 ISO-contrast steps CYP1=CYN15 to CYP8=CYN8
on 24 pages, see (2,4 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE19/AE19F0PX.PDF
AE19: For the 8 ISO-contrast steps CYN8=CYP8 to CYN1=CYP15
on 24 pages, see (2,4 MB)
http://standards.iso.org/iso/9241/306/ed-2/AE19/AE19F0NX.PDF
The ISO-test chart AE18 has in addition to AE19 an ISO/IEC image "flower motif".
Properties of this image are described in the main part
AEEI.
-------
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.