A study on Memory Colours

Memory colour has generated a sustained interest in the colour world. Previous studies mainly focused on the reflection colour chips and colour samples on real scenes or displays. Less attention was paid to the specific attributes of memory colour. In this paper, the forced choice psychophysical experiment method was used to study the preference, the colourfulness and the naturalness memory colours of 29 familiar objects on mobile displays by Chinese observers. The experiment collected the memory colours data and the representative memory colour was specified by CIELAB L*, a*, b* value. The intra-observer and inter-observer variations were analyzed by mean colour difference from the mean values, which was compared with other similar studies. An ellipsoid model was established to represent results in terms of memory colour centre and colour range in CIELAB a* b* space. At the same time, the results of this experiment were compared with those of previous experiments.

"Picture This": Advertising and Image in the New Zealand Architectural Journals in 1965

Throughout the 1960s advertising content in New Zealand's two leading architectural journals increased dramatically. In the case of the NZIA Journal, what was a staid professional publication without advertising in the 1950s, by the end of the 1960s carried significant advertising material including advertorial covers and the first colour centre pages. While not changing so dramatically, Home and Building nonetheless significantly increased the visibility of its advertising content over the same period. This research presents the findings of a comparative analysis of commercial advertising imagery found in the pages of Home & Building and the NZIA Journal for 1965. Throughout the 1960s the dominant publications dedicated to the activities of architects and architecture in New Zealand were the periodicals Home & Building and the NZIA Journal. From the point of view of advertisers it is important to emphasise that these periodicals were not market competitors. While the NZIA Journal was a professional journal published by the New Zealand Institute of Architects, Home & Building was published under the auspices of the NZIA, and consequentially the content differences between the two reflects a conscious effort on the part of the NZIA to distinguish between two different readerships. To a large extent this is reflected in the advertisements contained in each. The NZIA Journal shows an appeal on the part of the advertisers to architects as building professionals with its bias towards products and systems of construction. By contrast Home & Building advertising content tends to be directed towards a client market with a marked appeal to spaces of occupancy. This is exactly what we might expect to find; the professional journal directed to the work of the architect, and the more populous one appealing to potential clients. Consequentially much of the advertising content reflects this distinction. However what is less clear is the degree to which the advertising content either followed or directed this ideological editorial difference.In making a comparative analysis of the advertising material found in the pages of these two dominant forums attention has been given to the manner in which advertisers may have actively contributed to redefining the roles and responsibilities of "architect" and "client" during this period of 1960-70. I suggest that the NZIA may have had less control than it might have imagin ed over the nature of influence its two premiere publications were having on New Zealand architects and architecture in the 1960s.

Preferred skin reproduction centres for different skin groups

Producing preferred skin colours is vital for the digital images on mobile phone manufacturers. Previous studies investigated the skin colours only in chromatic plane excluding lightness. A psychophysical experiment was conducted to determine preferred skin colour centres for different skin colour types on mobile displays in a darkened room. Ten facial images were selected for the experiment to cover different skin colour types (Caucasian, Oriental, South Asian and African). A set of 49 predetermined colour centres uniformly sampled within the skin colour ellipsoid in CIELAB colour space was used to morph skin colours of test images. Thirty observers from each of the 3 ethnic groups (Caucasian, Oriental and South Asian) participated in the experiment. The preferred skin colour centre and region in the form of ellipsoid for each skin group were reported. It was found that the preferred colour centres from different skin colour types were very similar except their lightness as expected, and were also quite similar between the observers from different ethnic groups.

Colour centre generation in diamond for quantum technologies

Effective methods to generate colour centres in diamond and other wide band-gap materials are essential to the realisation of solid state quantum technologies based on such systems. Such methods have been the subject of intensive research effort in recent years. In this review, we bring together the various techniques used in the generation and positioning of colour centres in diamond: ion implantation, delta-doping, electron irradiation, laser writing and thermal annealing. We assess the roles and merits of each of these techniques in the formation of colour centres for different quantum technologies and consider future combinations of the techniques to meet the requirements of the most demanding applications.