BAM Federal Institute for Materials Research and Testing
Prof. Dr. Klaus
contact point :
site contains information about colour image reproduction, colour
education and colour vision
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
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 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
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)
Workshop 2006 "Symmetric Colour Vision Model, CIELAB
and Applications of CIELAB fo Scanners, Monitors and Printers
in Image Technology (in German)"
BAM-DIN-Workshop on Image Technology
(in english), April 18-19, 2005, BAM, Berlin
Image reproduction test files
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.
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
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 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
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
Solution with the Measurement, Transfer and Linearisation