Evaluation of chromatic cues for trappingBactrocera tau

2016 ◽  
Vol 73 (1) ◽  
pp. 217-222 ◽  
Author(s):  
Lei Li ◽  
Huabo Ma ◽  
Liming Niu ◽  
Dongyin Han ◽  
Fangping Zhang ◽  
...  
Keyword(s):  
Chromatic Cues

Coloring high-resolution near-infrared images using chromatic cues from low-resolution references

2015 ◽  
Author(s):  
Chester Brian Lim ◽  
Maria Monica Salud ◽  
Benjamin Uttoh ◽  
Carlo Noel Ochotorena ◽  
Cecille Adrianne Ochotorena ◽  
...  
Keyword(s):  
High Resolution ◽  
Near Infrared ◽  
Infrared Images ◽  
Low Resolution ◽  
Chromatic Cues

scholarly journals Colour cues proved to be more informative for dogs than brightness

2013 ◽  
Vol 280 (1766) ◽  
pp. 20131356 ◽  
Author(s):  
Anna A. Kasparson ◽  
Jason Badridze ◽  
Vadim V. Maximov
Keyword(s):  
Colour Vision ◽  
Visual Stimuli ◽  
Cone Photoreceptors ◽  
Lighting Conditions ◽  
Chromatic Cues

The results of early studies on colour vision in dogs led to the conclusion that chromatic cues are unimportant for dogs during their normal activities. Nevertheless, the canine retina possesses two cone types which provide at least the potential for colour vision. Recently, experiments controlling for the brightness information in visual stimuli demonstrated that dogs have the ability to perform chromatic discrimination. Here, we show that for eight previously untrained dogs colour proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity. Although brightness could have been used by the dogs in our experiments (unlike previous studies), it was not. Our results demonstrate that under natural photopic lighting conditions colour information may be predominant even for animals that possess only two spectral types of cone photoreceptors.

scholarly journals Chromaticity in the UV/blue range facilitates the search for achromatically background-matching prey in birds

2008 ◽  
Vol 364 (1516) ◽  
pp. 511-517 ◽  
Author(s):  
Nina Stobbe ◽  
Marina Dimitrova ◽  
Sami Merilaita ◽  
H. Martin Schaefer
Keyword(s):  
Search Task ◽  
Cyanistes Caeruleus ◽  
Chromatic Contrast ◽  
Background Matching ◽  
Long Time ◽  
Chromatic Cues ◽  
Blue Range ◽  
Underlying Mechanisms ◽  
Chromatic Properties ◽  
Blue Tits

A large variety of predatory species rely on their visual abilities to locate their prey. However, the search for prey may be hampered by prey camouflage. The most prominent example of concealing coloration is background-matching prey coloration characterized by a strong visual resemblance of prey to the background. Even though this principle of camouflage was recognized to efficiently work in predator avoidance a long time ago, the underlying mechanisms are not very well known. In this study, we assessed whether blue tits ( Cyanistes caeruleus ) use chromatic cues in the search for prey. We used two prey types that were achromatically identical but differed in chromatic properties in the UV/blue range and presented them on two achromatically identical backgrounds. The backgrounds had either the same chromatic properties as the prey items (matching combination) or differed in their chromatic properties (mismatching combination). Our results show that birds use chromatic cues in the search for mismatching prey, whereupon chromatic contrast leads to a ‘pop-out’ of the prey item from the background. When prey was presented on a matching background, search times were significantly higher. Interestingly, search for more chromatic prey on the matching background was easier than search for less chromatic prey on the matching background. Our results indicate that birds use both achromatic and chromatic cues when searching for prey, and that the combination of both cues might be helpful in the search task.

A neural and computational model for the chromatic control of accommodation

1990 ◽  
Vol 5 (6) ◽  
pp. 547-555 ◽  
Author(s):  
D. I. Flitcroft
Keyword(s):  
Image Quality ◽  
Computational Model ◽  
Cortical Neurons ◽  
Chromatic Aberration ◽  
Refractive State ◽  
Spatial Frequencies ◽  
Proposed Model ◽  
Band Pass ◽  
Chromatic Cues ◽  
Chromatic Processing

AbstractAccommodation is more accurate with polychromatic stimuli than with narrowband or monochromatic stimuli. The aim of this paper is to develop a computational model for how the visual system uses the extra information in polychromatic stimuli to increase the accuracy of accommodation responses. The proposed model is developed within the context of both trichromacy and also the organization of spatial and chromatic processing within the visual cortex.The refractive error present in the retinal image can be estimated by comparing image quality with and without small additional changes in refractive state. In polychromatic light, the chromatic aberration of the eye results in differences in ocular refractive power for light of different wavelengths. As a result, the refractive state of the eye can be estimated by comparing image quality in the three types of cone photoreceptor. The ability of cortical neurons to perform such comparisons on image quality with a crude form of spatial-frequency analysis is examined theoretically. It is found that spatially band-pass chromatically opponent neurons (that may correspond to double opponent neurons) can perform such calculations and that chromatic cues to accommodation are extracted most effectively by neurons responding to spatial frequencies of between 2 and 8 cycles/deg.

scholarly journals Triggerfish uses chromaticity and lightness for object segregation

2017 ◽  
Vol 4 (12) ◽  
pp. 171440 ◽  
Author(s):  
Laurie Mitchell ◽  
Karen L. Cheney ◽  
Fabio Cortesi ◽  
N. Justin Marshall ◽  
Misha Vorobyev
Keyword(s):  
Visual Perception ◽  
Human Visual Perception ◽  
Chromatic Contrast ◽  
Visual Patterns ◽  
Ishihara Test ◽  
Achromatic Contrast ◽  
Chromatic Cues ◽  
Object Segregation

Humans group components of visual patterns according to their colour, and perceive colours separately from shape. This property of human visual perception is the basis behind the Ishihara test for colour deficiency, where an observer is asked to detect a pattern made up of dots of similar colour with variable lightness against a background of dots made from different colour(s) and lightness. To find out if fish use colour for object segregation in a similar manner to humans, we used stimuli inspired by the Ishihara test. Triggerfish ( Rhinecanthus aculeatus ) were trained to detect a cross constructed from similarly coloured dots against various backgrounds. Fish detected this cross even when it was camouflaged using either achromatic or chromatic noise, but fish relied more on chromatic cues for shape segregation. It remains unknown whether fish may switch to rely primarily on achromatic cues in scenarios where target objects have higher achromatic contrast and lower chromatic contrast. Fish were also able to generalize between stimuli of different colours, suggesting that colour and shape are processed by fish independently.

Visual Attention to Color: Parvocellular Guidance of Attentional Resources?

2002 ◽  
Vol 13 (2) ◽  
pp. 180-184 ◽  
Author(s):  
Robert J. Snowden
Keyword(s):  
Eye Movements ◽  
Attentional Capture ◽  
Target Identification ◽  
Dominant Role ◽  
Attentional Resources ◽  
Dynamic Noise ◽  
Abrupt Changes ◽  
Chromatic Cues ◽  
Detection And Localization

Although transient changes in luminance have been well documented to automatically attract attention to their location, experiments looking at abrupt changes in color have failed to find similar attentional capture. These results are consistent with current theories of the role of the magnocellular (M) and parvocellular (P) streams that postulate that the M stream, which is “color-blind,” plays the dominant role in guiding attention and eye movements. The experiment reported here used stimuli that contained only information defined by color, and masked residual luminance information with dynamic noise, to assess the capacity of purely chromatic cues to automatically guide spatial attention. Such stimuli were as effective as those containing large luminance signals in guiding attention. To the extent that these purely chromatic signals isolated the P stream, these results suggest that this stream is also capable of automatic attentional capture. Hence, color vision not only aids target identification but also is a strong aid for target detection and localization.

scholarly journals Combining achromatic and chromatic cues to transparency

2010 ◽  
Vol 5 (8) ◽  
pp. 566-566 ◽  
Author(s):  
J. M. Fulvio ◽  
M. Singh ◽  
L. T. Maloney
Keyword(s):  
Chromatic Cues

scholarly journals How chromatic cues can guide human eye growth to achieve good focus

2021 ◽  
Vol 21 (5) ◽  
pp. 11
Author(s):  
Timothy J. Gawne ◽  
Rafael Grytz ◽  
Thomas T. Norton
Keyword(s):  
Human Eye ◽  
Eye Growth ◽  
Chromatic Cues

Chromatic Cues for Face Detection in Natural Scenes

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 294-294
Author(s):  
A Oliva ◽  
S Akamatsu ◽  
P G Schyns
Keyword(s):  
Face Detection ◽  
Reaction Times ◽  
Detection Task ◽  
Natural Scenes ◽  
Colour Space ◽  
Affect Detection ◽  
Detection Of Objects ◽  
Chromatic Cues ◽  
Colour Histograms ◽  
Euclidian Distances

One of the challenging problems of human and machine vision is the detection of objects against complex backgrounds. Our research addresses the question of how faces can be very quickly detected in naturalistic scenes on the basis of luminance and chromatic cues. Although luminance information varies with pose and illumination differences, chromatic information is by and large invariant under these transformations. Hence, chromatic information might be a very powerful cue for segmentation and detection. We compared faces of different pigmentation against background scenes of different colours. Specifically, colour histograms were computed in a perceptually uniform colour space (L*u*v*). We computed the Euclidian distances between the averages of the colour histograms of faces and scenes in L*u*v*. This metric was used to calibrate the contrast between face and scene colour in the experimental design. In a face detection task, subjects saw faces against scene backgrounds at a different distance in colour space. Each combination face - scene was presented for 120 ms (to prevent saccadic explorations), and the subject's task was to indicate whether or not a face was present. Controls involved face - scene pairs on an isoluminant background. Results revealed that luminance information did not affect detection on the basis of chromatic cues. Importantly, the metric of detectability in L*u*v* space between scene and faces predicted reaction times to detection.

scholarly journals Perception of Chromatic Cues During Host Location by the Pupal ParasitoidPimpla turionellae(L.) (Hymenoptera: Ichneumonidae)

2004 ◽  
Vol 33 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Sabine Fischer ◽  
Jörg Samietz ◽  
Felix L. Wäckers ◽  
Silvia Dorn
Keyword(s):  
Host Location ◽  
Chromatic Cues
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