2005-06-01 XY06 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
Werner Daum
Unter den Eichen 87
12205 Berlin
+49 30 8104-1910


+49 30 8104-1919
+49 30 8104-1919

+49 30 8104-1917


  Visual Methods and Image Reproduction  
  Transformation of colour coordinates  

Transformation between CIELAB and device color coordinates (olv*, cmy*, sRGB, etc.) and vice versa

Transformation of colour coordinates used in
ISO/IEC 15775: 1999-12
ISO/IEC TR 19797:2004
ISO/IEC TR 24705:2005
DIN 33866-1 to 5: 2000-07 and
DIN 33870:2001-01

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

Colour coordinates in CIELAB related colour spaces for a 5 step colour series cyan blue ­ white

The table shows corresponding colours for a 5 step colour series white ­ cyan blue 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 chart no. 2 (see Fig. B4).

Application examples which show the need for the transformation between LAB* (CIELAB) and device coordinates cmyn*, olv*, etc.

There are new colorimetric devices, e. g. scanners, digital cameras and others, on the market which produce LAB* (CIELAB) output coordinates. For many applications it is necessary to transform the LAB* coordinates into device coordinates, e. g. cmyn* or olv*, of standard printing (PR18) or into similar coordinates of standard television (TV00 or TV18).

Transformation between LAB*- and device coordinates olv*, cmy*, ncu*, ctu*, und sRGB
VM03TE: 000901: Transformation of LAB* colour coordinates (absolute CIELAB colour space) to lab* , LAB* da, lab*da, olv*, cmy*, ncu*, ctu*, and sRGB coordinates
Series 7110, ..., 7190, 7210, ..., 7290, 7310, ..., 7390, 7410, ..., 7490
Series 8650, 8750, 8870, 8880, 8890

Examples of colour coordinate transformations

d8/8bit digital and hexadecimal coding of relative cmyn* colour coordinates

D8/8bit digital and hexadecimal coding of absolute CMYN* colour coordinates

For technical reports about colour coordinate transformations go to "Publications" on home

Transformation of CIELAB to the digital codes olv*, cmy* and sRGB

DE07: 010125: Transformation of CIELAB colour codes of standard TV colours to the digital codes olv*, cmy* and sRGB of TV colours