This paper presents a negative result: current machine colour constancy algorithms are not good enough for colour-based object recognition. This result has surprised us since we have previously used the better of these algorithms successfully to correct the colour balance of images for display. Colour balancing has been the typical application of colour constancy, rarely has it been actually pu...

The colour vision of domestic chicks (Gallus gallus) was investigated by training them to small food containers decorated with tilings of grey and coloured rectangles. Chicks learn to recognise the colour quickly and accurately. Chicks have four types of single-cone photoreceptor sensitive to ultraviolet, short-, medium- or long-wavelength light. To establish how these receptors are used for co...

The colours we see reflect not only the light wavelengths presently being detected, but also those already received. To understand colour constancy therefore requires an understanding of adaptation in the visual system.

To perform their job safely firefighters must be able to identify colours on industrial gas cylinders, portable fire extinguishers, road traffic signals and several pieces of firefighting equipment. Although good colour vision is necessary we believe that the existing colour vision standard, which bars entry to the fire service to applicants who fail more than two plates of the Ishihara test, i...

A follow-up study of colour vision in two patients with gyrate atrophy was performed. Gyrate atrophy was diagnosed in the first patient at the age of 17 years. Her colour vision was first tested at the age of 25 years; at the follow-up examination 7 years later, she correctly interpreted the Standard Pseudoisochromatic Plates part 2, however, with one mistake due to lens opacity. In the Farnswo...

THE analysis of colour defects and individual differences in normal colour vision requires an apparatus in which spectral stimuli are used. It should be possible to determine the following: (1) Relative luminous efficiency of spectral light (luminosity curve). (2) Threshold of wavelength discrimination in spectrum (hue discrimination curve). (3) Threshold of saturation discrimination in spectru...

Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly...

At one time during the past few months the writer's attention was called to the following statement made in January I926 by an eminent surgeon: "In fishes a falci-ft \form ligament is attached to the back of the lens and to the back of the eye for N /fX,E1 focusing. They have no color vision. This fact will be disputed by those who sell q .; ~~~artificial flies at high prices.""5 A subse-"~ Xe\...

Today, there is good knowledge of the physiological basis of bird colour vision and how mathematical models can be used to predict visual thresholds. However, we still know only little about how colour vision changes between different viewing conditions. This limits the understanding of how colour signalling is configured in habitats where the light of the illumination and the background may sh...

Humans lose colour vision at night and it has often been assumed that this happens to other animals as well. It is not true of nocturnal moths, however: a recent study has shown that the elephant hawk moth makes use of trichromatic colour vision when seeking flowers by starlight.