The effect of gloss and viewing flare on colour appearance

Abstract

In colour management it is often desirable to obtain matching colours across media which impart different gloss characteristics to the image. Furthermore, this matching is often assessed in situations in which there is a high degree of viewing flare. These factors impact colour appearance in a way that is difficult to measure with existing techniques of colorimetry. Recent studies undertaken in evaluating colour difference have suggested to us that this is particularly significant with dark colours. In order to improve prediction of matching colours in real viewing conditions it is necessary to be able to predict viewing flare - and the effects of this when comparing samples of differing gloss in these viewing conditions. This will enable modelling of a correction to colorimetric data to improve appearance predictions in such circumstances. A hypothesis for this model is presented - together with the results of some preliminary work to justify the need for it.

Tony Johnson

Research Interests
• Colour Imaging
• Gloss
• Colour measurement
• Image Processing
• Printing Technology

Current Research

Since the end of 2004 I have largely retired but prior to that I spent over 30 years working in colour imaging research for the printing industry. I helped develop many colour and image processing algorithms for electronic imaging and undertook research in many aspects of colour reproduction by printing. I was also heavily involved in international standardisation for printing for many years.

During my last 10 years prior to retirement, as well as being a Professor at the LCP undertaking both research and teaching in colour imaging, I undertook consultancy work in colour imaging. Prior to that I worked in research for both Pira and Crosfield Electronics who, at that time, was one of the market leaders in electronic colour imaging.

I am in the process of publishing papers based on my research activity prior to retirement, dealing with the measurement of gloss and its effect on colour management. My time at LCC is now spent supervising research students. Currently I am supervising 5 postgraduate students working on various aspects of colour imaging, including colour management on non-paper substrates, colour difference measurement for complex images, colour image quality measurement, n-colour printing.