The same image  viewed on different displays is likely to look different due to differences in hardware and other display settings. To obtain the same image on different displays requires the displays to be calibrated with a measurement device that measures the luminance and colour properties of the display output. Most end users do not have access to calibration equipment.


A low-tech solution to calibration is to use the human observer as the calibration tool. This is possible because colour-normal human observers show a remarkable constancy in unique hue judgements with inter-observer variability being  about twice as high as intra-observer variability. This consistency across observers can be exploited and these invariant hue judgements of the  human observer can be used as an internal standard.


To achieve device calibration using human visual judgements requires two step: (1) Gamma correction [1,5, 6], and (2) the colour calibration [2,3,4]. The process is shown in the figure below.






Collaboration with the Tate Gallery showing how the process works. Please click here



Dr. Kaida Xiao, School of Design, University of Leeds

Dr Dimos Karatzas, CVC, Barcelona, Spain



[1].     Xiao, K., Fu, C., Karatzas, D., & Wuerger, S. (2010). Visual gamma correction for LCD displays. Displays, 32(1), 17-23.

[2]. Wuerger, S.M., Karatzas, D. and Meyer, G. (2005)  A Display Calibration Technique based on Invariant Human Colour Mechanisms, Proceedings of the 2nd Symposium on Applied Perception in Graphics and Visualisation, ACM SIGGRPAH, Spain, 239-245.

[3].  Wuerger, S.M. (2006)  The linearity of colour appearance mechanisms, Proceedings of the 3nd European Conference on Color in Graphics, Imaging and Vision, Leeds, UK, pp. 1250-1259.

[4]. Wuerger, S. and Karatzas (2006).  A Hardware-Independent Colour Calibration Technique, Annals of the British Machine Vision Association, 3, 1-10.

[5]. Xiao K, Fu C, Karatzas D, Wuerger S. (2009). An improved method of visual gamma correction for LCD displays. In: Proceedings of the 11th Congress of the International Colour Association (AIC). Sydney, Australia.

[6] Parraga, A, Roca-Vila, J.,  Wuerger, S.  and Karatzas, D.  (2014). Limitations of visual gamma corrections in LCD displays. Displays, DOI: 10.1016/j.displa.2014.07.001



2001  Device-Independent Colour Calibration. UK Patent (0126696.4)
2006  European Patent granted (
2008  US Patent granted (US 20050052344)


Acknowledgement of support

Northwest Development Agency for 'Device-Independent Colour Calibration'
Merseyside Investment Funds for ‘Colour calibration based on human perceptual judgments’
Proof-of-concept funding from the Northwest Development Agency: ‘Colour calibration based on human perception’
Innovation Voucher (Daresbury) for a Colour vision Project at the Tate Gallery, Liverpool
ICI/AkzoNobel: ‘Device-independent Visual Display Calibration”
Technology Strategy Board (KTP)  ‘Device-independent Visual Display Calibration’