2007-12-20 INDEX_I EN | DE zurück | vor

BAM Federal Institute for Materials Research and Testing

Prof. Dr. Klaus Richter
Visual Methods and Image Reproduction in Non-Destructive Testing (NDT)

contact point :

BAM Division VIII.1
Measurement and Testing Technology; Sensors
Dr.-Ing.
Werner Daum
Unter den Eichen 87
12205 Berlin
phone:
+49 30 8104-1910
email:

Werner.Daum@bam.de

secretariat:
phone:
+49 30 8104-1919
+49 30 8104-1919

fax:

+49 30 8104-1917

     
 

This web site contains information about colour image reproduction, colour education and colour vision
Test files for image reproduction are the basis for DIN and ISO/IEC standards.

Attention: Parts of this website serve as an archive and are no longer regularly checked. Concerning their technical functions, many of the documents published on this website are not error-free.

 
 

National and international standards have been developed under the leadership of BAM VIII.34 and BAM VIII.1
The standards describe and improve image reproduction of colour devices in the office.
The standards are for the different office devices, e. g. copiers, printers, scanners and monitors.

Draft standards, application papers, meeting reports, and materials for colour education are included in this web site.

Basic research material about colour vision and some work for the CIE is also available, see publications

6th BAM-DIN-Workshop 2007 on Image Technology (in english), December 3, 2007, BAM, Berlin
For the program of the 6th BAM-DIN-Workshop 2007 including all abstracts of the papers and with most of the presented papers in the format PDF or PPT, see
info07

For recent series of BAM-test charts according to draft DIN E 33872-1 to 6:2007 for Relative Colour Image Reproduction in PDF format, see
33872E

For the recent series of BAM-test charts for Image Technology in PDF format, see
ZE1.HTM

For colour samples in four hue planes of the elementary colour system which is used in DIN E 33872-1 to -6:2007, see (900 kByte, 6 pages)
L94E00NP.PDF

Workshop 2006 "Symmetric Colour Vision Model, CIELAB and Applications of CIELAB fo Scanners, Monitors and Printers in Image Technology (in German)"
For users in the areas of: Graphic Design, Computer Graphic, Colorimetry and Colour Management
Saturday, September 30, 2006, 9.00 to 12.30h during the
FARBINFO 2006 at the Technical University Dresden, see
WS6E

BAM-DIN-Workshop on Image Technology (in english), April 18-19, 2005, BAM, Berlin
For information about the program, the invitation to present a paper or poster, the registration and the reasons for this workshop, see info05

Publications
It may be useful to look at the application papers first, please see the section "Technical publications" for recent and older publications.

Unique hue colours RGBJ and reproduction colours CMYOLV
PDF, PS, TXT

Image reproduction test files
Furthermore this web site contains many "image reproduction test files", see please section "Image reproduction tests".
The test files are given in the PostScript format (PS), Portable Document Format (PDF) and other formats.
The test files are useful to test the influence of the file format, the application software, the printer driver or the output device on the colour output.

ISO/IEC-test chart no. 2 according to ISO/IEC 15775
PDF, PS, TXT

ISO/IEC-test charts contain a lot of testing elements including Siemens-stars and Landolt-rings in different basic colours, 14 CIE-test colours, 16 step colour series. An image includes a 16 step gray scale which was equally spaced in the original and the CIE-test colours.
For other "image reproduction test files", see please the section "Image reproduction tests".


Problem of different output for CIELAB and corresponding colour series
One can define the colours in different colour spaces, e. g. LAB* (CIELAB), cmyn*, olv* etc. The colour output may be very different for the corresponding colours.


CIELAB and device space coordinates of the five step colour series between cyan blue (C) and white (W)
PDF, PS, TXT

The table shows the absolute colour coordinates LAB* (CIELAB) and the corresponding relative colour coordinates cmyn* and olv* for a 5 step colour series White ­ Cyan in the three colour spaces CIELAB, CMYN and OLV. The calculations are based on the 16 step colour series of ISO/IEC 15775 which are equally spaced in the analog and digital ISO/IEC-test charts (see Fig. B4 of the above ISO/IEC-test charts no. 2).

16 step CIELAB colour scales and linearisation of the reproduction
There are 16 step colour scales equally spaced in CIELAB in analog and digital ISO/IEC-test charts. The output of a test file on a device is the basis for the linearisation of the reproduction process including application software, printer driver and output device.


16 step colour series between white and the colours CMYOLV which are equally spaced in the CIELAB colour space
PDF, PS, TXT


16 step colour series which are equally spaced in the orange red hue plane W­O­N
PDF, PS, TXT

The two figures show different 16 step colour series. Similar as for the 5 step colour series in the above table all the CIELAB coordinates are defined. A transformation exists betweeen the absulte LAB* (CIELAB) data and the relative cmy* and olv* device data. For further information see the section "Transformation of colour coordinates".

Linearisation method for the reproduction
The linearisation method for the output process needs visual or colorimetric colour measurement of a start output, see please "Technical publications".

Test chart with 128 basic colours of eight 16 step series which are defined in relative cmyn* colour coordinates
PDF, PS, TXT

The start output of the above 128 colours define the linearisation data of a device system. The visual or colorimetric colour measurement data of a start output are used by the linearisation method, see section "Image reproduction linearisation"

The linearisation method can be applied for black and white printers and with simple technical knowledge. The method will be used by students in a competition of colour science. This competition is during the international colour meeting FARB-INFO '02, see info02/FI02WE.PDF

Linearisation data for a reproduction process
The linearisation data (measurement of the above 128 colours) may be included at different places for a reproduction process:
1. in the test file
2. in the startup directory of the software Adobe Acrobat Distiller
3. in PostScript printer driver (PPD) file for printers
4. in the memory of PostScript printers.

A file with linearisation data which may be used at the four above places is the linearisation file info02/MTL20000.PS. This file includes PostScript code of about 50 lines with different relative visual data (linear, square root and square) and the colorimetric CIELAB lightness data L* of a start output of a printer. The last data may be changed according to the start output of the device system used.

Requirement for a similar output by the consumers
A similar output is often required by consumers but software and hardware produce for the DIN- and ISO/IEC-test files often different colours. The test file output is often influenced and changed by the computer operating system, the file format, the application software, the printer diver, and the output device. The reproduction differences become visible. The colour differences are sometimes unacceptable, e. g. if the mean colour differences reach about 20 CIELAB.

Solution with the Measurement, Transfer and Linearisation (MTL) code
With the MTL PS software code, which includes the output measurement data of 16 (achromatic) or 128 (chromatic) colours in the startup directory of the software Adobe Acrobat Distiller, the linearisation of the output is possible, see the section "Image reproduction linearisation"