scholarly journals Disruptive coloration, crypsis and edge detection in early visual processing

2006 ◽  
Vol 273 (1598) ◽  
pp. 2141-2147 ◽  
Author(s):  
Martin Stevens ◽  
Innes C Cuthill
Keyword(s):  
Edge Detection ◽  
Pattern Matching ◽  
Visual Processing ◽  
Colour Vision ◽  
The Body ◽  
Detection Algorithms ◽  
Avian Predators ◽  
Early Visual Processing ◽  
Disruptive Coloration ◽  
Risk Of Predation

Many animals use concealing markings to reduce the risk of predation. These include background pattern matching (crypsis), where the coloration matches a random sample of the background and disruptive patterns, whose effectiveness has been hypothesized to lie in breaking up the body into a series of apparently unrelated objects. We have previously established the effectiveness of disruptive coloration against avian predators, using artificial moth-like stimuli with colours designed to match natural backgrounds as perceived by birds. Here, we investigate the mechanism by which disruptive patterns reduce detectability, using a computational vision model of edge detection applied to photographs of our experimental stimuli, calibrated for bird colour vision. We show that, disruptive coloration is effective by exploiting edge detection algorithms that we use to model early visual processing. Thus, ‘false’ edges are detected within the body rather than at its periphery, so inhibiting successful detection of the animal's body outline.

scholarly journals Computerized or Automated Object Recognition and Analysis of Pattern Matching in Runways Using Surface Track Data

2021 ◽  
Vol 23 (11) ◽  
pp. 159-165
Author(s):  
JAYANTH DWIJESH H P ◽  
◽  
SANDEEP S V ◽  
RASHMI S ◽  
◽  
...  
Keyword(s):  
Edge Detection ◽  
Object Detection ◽  
Pattern Matching ◽  
Aerial Images ◽  
3 Dimensional ◽  
Detection Techniques ◽  
Detection Algorithms ◽  
Detection Analysis ◽  
Efficient Detection ◽  
Minimal Damage

In today’s world, accurate and fast information is vital for safe aircraft landings. The purpose of an EMAS (Engineered Materials Arresting System) is to prevent an aeroplane from overrunning with no human injury and minimal damage to the aircraft. Although various algorithms for object detection analysis have been developed, only a few researchers have examined image analysis as a landing assist. Image intensity edges are employed in one system to detect the sides of a runway in an image sequence, allowing the runway’s 3-dimensional position and orientation to be approximated. A fuzzy network system is used to improve object detection and extraction from aerial images. In another system, multi-scale, multiplatform imagery is used to combine physiologically and geometrically inspired algorithms for recognizing objects from hyper spectral and/or multispectral (HS/MS) imagery. However, the similarity in the top view of runways, buildings, highways, and other objects is a disadvantage of these methods. We propose a new method for detecting and tracking the runway based on pattern matching and texture analysis of digital images captured by aircraft cameras. Edge detection techniques are used to recognize runways from aerial images. The edge detection algorithms employed in this paper are the Hough Transform, Canny Filter, and Sobel Filter algorithms, which result in efficient detection.

scholarly journals Outline and surface disruption in animal camouflage

2008 ◽  
Vol 276 (1657) ◽  
pp. 781-786 ◽  
Author(s):  
Martin Stevens ◽  
Isabel S Winney ◽  
Abi Cantor ◽  
Julia Graham
Keyword(s):  
Body Shape ◽  
Luminance Contrast ◽  
The Body ◽  
Maximum Effect ◽  
High Contrast ◽  
High Luminance ◽  
Effective Surface ◽  
Avian Predators ◽  
Disruptive Coloration ◽  
Visual Mechanism

Camouflage is an important strategy in animals to prevent predation. This includes disruptive coloration, where high-contrast markings placed at an animal's edge break up the true body shape. Successful disruption may also involve non-marginal markings found away from the body outline that create ‘false edges’ more salient than the true body form (‘surface disruption’). However, previous work has focused on breaking up the true body outline, not on surface disruption. Furthermore, while high contrast may enhance disruption, it is untested where on the body different contrasts should be placed for maximum effect. We used artificial prey presented to wild avian predators in the field, to determine the effectiveness of surface disruption, and of different luminance contrast placed in different prey locations. Disruptive coloration was no more effective when comprising high luminance contrast per se , but its effectiveness was dramatically increased with high-contrast markings placed away from the body outline, creating effective surface disruption. A model of avian visual edge processing showed that surface disruption does not make object detection more difficult simply by creating false edges away from the true body outline, but its effect may also be based on a different visual mechanism. Our study has implications for whether animals can combine disruptive coloration with other ‘conspicuous’ signalling strategies.

Visual body processing’s associations to Body Mass Index and internalization of societal beauty ideals

2020 ◽  
Author(s):  
Valentina Cazzato ◽  
Elizabeth Walters ◽  
Cosimo Urgesi
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Visual Processing ◽  
The Body ◽  
Configural Processing ◽  
Cultural Ideals ◽  
Beauty Ideals ◽  
Female Bodies ◽  
Processing Mechanisms ◽  
Attention To Detail

We examined whether visual processing mechanisms of the body of conspecifics are different in women and men and whether these rely on westernised socio-cultural ideals and body image concerns. Twenty-four women and 24 men performed a visual discrimination task of upright or inverted images of female or male bodies and faces (Experiment 1) and objects (Experiment 2). In Experiment 1, both groups of women and men showed comparable abilities in the discrimination of upright and inverted bodies and faces. However, the genders of the human stimuli yielded different effects on participants’ performance, so that male bodies and female faces appeared to be processed less configurally than female bodies and male faces, respectively. Interestingly, altered configural processing for male bodies was significantly predicted by participants’ Body Mass Index (BMI) and their level of internalization of muscularity. Our findings suggest that configural visual processing of bodies and faces in women and men may be linked to a selective attention to detail needed for discriminating salient physical (perhaps sexual) cues of conspecifics. Importantly, BMI and muscularity internalization of beauty ideals may also play a crucial role in this mechanism.

scholarly journals Fractional Order Processing of Satellite Images

2021 ◽  
Vol 11 (11) ◽  
pp. 5288
Author(s):  
Manuel Henriques ◽  
Duarte Valério ◽  
Rui Melicio
Keyword(s):  
Edge Detection ◽  
Fractional Order ◽  
High Performance ◽  
Satellite Images ◽  
Automatic Detection ◽  
Automatic Processing ◽  
Order Processing ◽  
Detection Algorithms ◽  
Grey Scale ◽  
Fixed Set

Nowadays, satellite images are used in many applications, and their automatic processing is vital. Conventional integer grey-scale edge detection algorithms are often used for this. This study shows that the use of color-based, fractional order edge detection may enhance the results obtained using conventional techniques in satellite images. It also shows that it is possible to find a fixed set of parameters, allowing automatic detection while maintaining high performance.

scholarly journals Directional selectivity and its use in early visual processing

1981 ◽  
Vol 211 (1183) ◽  
pp. 151-180 ◽  
Keyword(s):  
Visual Processing ◽  
Visual Motion ◽  
Time Derivative ◽  
Receptive Fields ◽  
Specific Model ◽  
Zero Crossings ◽  
Second Stage ◽  
Early Visual Processing ◽  
Local Direction ◽  
Zero Values

The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of ∇ 2 G(x, y) ∗ I(x, y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative ∂[∇ 2 G(x, y) ∗ l(x, y) ]/∂ t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180°. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.

scholarly journals Increased plasticity of the bodily self in eating disorders

2011 ◽  
Vol 42 (4) ◽  
pp. 819-828 ◽  
Author(s):  
E. Eshkevari ◽  
E. Rieger ◽  
M. R. Longo ◽  
P. Haggard ◽  
J. Treasure
Keyword(s):  
Eating Disorders ◽  
Visual Processing ◽  
Subjective Experience ◽  
Emotional Dysregulation ◽  
The Body ◽  
Self Report ◽  
Healthy Controls ◽  
Drive For Thinness ◽  
Maintenance Factors ◽  
Self Objectification

BackgroundThe rubber hand illusion (RHI) has been widely used to investigate the bodily self in healthy individuals. The aim of the present study was to extend the use of the RHI to examine the bodily self in eating disorders (EDs).MethodThe RHI and self-report measures of ED psychopathology [the Eating Disorder Inventory – 3 (EDI-3) subscales of Drive for Thinness, Bulimia, Body Dissatisfaction, Interoceptive Deficits, and Emotional Dysregulation; the 21-item Depression, Anxiety and Stress Scale (DASS-21); and the Self-Objectification Questionnaire (SOQ)] were administered to 78 individuals with an ED and 61 healthy controls.ResultsIndividuals with an ED experienced the RHI significantly more strongly than healthy controls on both perceptual (i.e. proprioceptive drift) and subjective (i.e. self-report questionnaire) measures. Furthermore, both the subjective experience of the RHI and associated proprioceptive biases were correlated with ED psychopathology. Approximately 23% of the variance for embodiment of the fake hand was accounted for by ED psychopathology, with interoceptive deficits and self-objectification significant predictors of embodiment.ConclusionsThese results indicate that the bodily self is more plastic in people with an ED. These findings may shed light on both aetiological and maintenance factors involved in EDs, particularly visual processing of the body, interoceptive deficits, and self-objectification.

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