Conference Report by Seo Young Choi, Colour & Imaging Group, Colour & Polymer Chemistry Department, University of Leeds, UK

The 10th Congress of the International Colour Association, AIC Colour 05, was held from May 8th to 13th, 2005 in Granada, Spain. A total of 548 attendees experienced 208 high-quality oral papers and 211 posters. In addition, the temperature was perfect with warm and sunny weather.

The organisers (the Spanish Colour Committee) prepared several social programmes which enabled the participants to exchange their ideas within a relaxed and pleasant atmosphere: Andalusian dinner, and Alhambra and Generalife visit. The conference began with The symbolic chromatic content of Japanese painting and its relation to western art by Fernando García Gutiérrez. There was an award event on third day: John Hutchings (a visiting fellow at the University of Leeds) received the 2005 Deane B. Judd Award from the AIC and gave a fascinating presentation entitled "Colour and Power and Ethics". The overall programme was divided into 19 symposiums with 22 invited papers and 17 oral sessions:

Symposium (number of invited papers) Multispectral Colour Science I: Spectral colour imaging systems (1) Multispectral Colour Science II: Spectral colour imaging and illuminants (1) Multispectral Colour Science III, IV: Art spectral colour imaging I (1), II (2) Multispectral Colour Science V: Spectral colour estimation Colour vision and aging (1) Colour vision with natural images: physics and psychophysics I (2), II Photoreceptors and colour vision mechanisms (2) Computational colour constancy (2) Colour appearance: ordinal, interval& ratio scales (2) Evaluation of image quality (2) Colour image capture, devices and media (1) Environmental colour design I (1), II, III (1) How do we teach colour today and tomorrow? (1) Art and colour (1)

Oral Session Colour vision I, II Colour in computer vision Applied colorimetry I, II, III Colour physics Colour appearance Camera and displays characterisation Gamut mapping, characterisation and displays Colour differences Colour education Colour emotion Colour preference Colour in architecture Colour, culture and design Colour and painting

Five sessions were allocated for the 7th Symposium on Multispectral Colour Science. Three good invited talks were given from Chiba University in Japan. N. Tsumura introduced the basic points and frame-work for the reproduction of colour and appearance (including other attributes such as glossiness, graininess and translucency). H. Haneishi described a method for expanding dynamic range that uses a six-band camera consisting of three high-sensitive bands and three low-sensitive bands. Y. Miyake summarised the state of research in Multispectral Imaging: Past, Present and Future. These were very helpful for a 2nd year PhD student to learn multispectral imaging.

In the symposium, on the evaluation of image quality, S. Westland (Leeds University, UK) proposed a computational model of luminance CSF (contrast sensitivity function) which can take account of the dependence of the luminance CSF on mean luminance and colour. This is important, because traditional estimates of the luminance CSF based upon achromatic stimuli are thought to over-estimate the visual system's sensitivity to luminance contrast in colour image.

N. Katoh (Sony, Japan) suggested practical solutions to improving the accuracy of colour reproduction for digital still cameras in the Colour Image Capture, Devices and Media symposium. A two-dimensional visualisation method for colour filter spectral sensitivity evaluation was proposed. Also, extended-gamut colour spaces were discussed with a view to storing those colour images captured and processed by digital still cameras.

W.Y.Lee's (Leeds University, UK) presentation concerned the 3D colour-form combinations used to investigate 20 imagery scales in the Colour Preference session. Finally, the imagery-based and colorimetric-based preference models were introduced. In the Colour Emotion session, there were several debates about this, a new research topic in the field of colour science, including its definition, suitable research methods and applications of colour emotion. Among the audience, a few psychologists argued that "colour emotion scales" were semantic scales rather than real emotion terms, in contrast, the current colour emotion researchers have indicated that semantic scales are the current focus and that real emotion terms will be investigated as future work using non-psychophysical methods, such as through psycho-physiological and psycho-neurological techniques. While colour emotion studies have been suggested to be beneficial to practical design - especially in the evaluation stage of colour scheme development - there are still a few designers who disagree and seem to be against this assertion.

Two late afternoons on May 9th and 12th were devoted to ten poster sessions. M. S. Millán, (Universidad Politécnica de Cataluña, Spain) in the Colour in Computer Vision and Image Processing session, demonstrated that CIELAB colour difference between image pixels could be used as a metric in the application of derivative sharpening filters such as Laplacian.

In the Colour in Art session, T. Nakamura (Nara Saho College, Japan) gave an interesting analysis about the relationship between colour and sense-of-season for Japanese and Spanish. All poster sessions were widely attended with many interactive discussions taking place.

This was the first opportunity for me to attend such a conference. From it I received much insight & motivation as to how to study and address many various research topics. I would really like to express appreciation to the Royal Photographic Society, Imaging Science Group for awarding me a research student travel grant.