scholarly journals Transparent layer constancy is improved by motion, stereo disparity, highly regular background pattern, and successive presentation

2019 ◽  
Vol 19 (12) ◽  
pp. 16
Author(s):  
Charlotte Falkenberg ◽  
Franz Faul
Keyword(s):  
Successive Presentation ◽  
Stereo Disparity ◽  
Transparent Layer ◽  
Motion Stereo ◽  
Background Pattern

scholarly journals Perceptual transparency from image deformation

2015 ◽  
Vol 112 (33) ◽  
pp. E4620-E4627 ◽  
Author(s):  
Takahiro Kawabe ◽  
Kazushi Maruya ◽  
Shin’ya Nishida
Keyword(s):  
Liquid Layer ◽  
Visual Cues ◽  
Human Vision ◽  
Light Refraction ◽  
Image Deformation ◽  
Dynamic Image ◽  
Transparent Layer ◽  
Transparent Liquid ◽  
High Level ◽  
Background Pattern

Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid’s surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of “invisible” transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation.

scholarly journals All Shades of Shrimp: Preferences of Colour Morphs of a Freshwater Shrimp Neocaridina davidi (Decapoda, Atyidae) for Substrata of Different Colouration

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1071
Author(s):  
Zuzanna Plichta ◽  
Jarosław Kobak ◽  
Rafał Maciaszek ◽  
Tomasz Kakareko
Keyword(s):  
Invasive Species ◽  
Niche Breadth ◽  
Habitat Preferences ◽  
Choice Experiments ◽  
Freshwater Shrimp ◽  
Invasive Potential ◽  
Proper Management ◽  
Aquarium Hobby ◽  
Colour Morphs ◽  
Background Pattern

An ornamental freshwater shrimp, Neocaridina davidi, is popular as an aquarium hobby and, therefore, a potentially invasive species. There is a growing need for proper management of this species to determine not only their optimum breeding conditions, but also their ability to colonise novel environments. We tested habitat preferences of colour morphs (brown, red, white) of N. davidi for substratum colour (black, white, grey shades, red) and fine or coarse chess-board patterns to recognise their suitable captivity conditions and predict their distribution after potential release into nature. We conducted laboratory choice experiments (n = 8) with three individuals of the same morph exposed for two hours to a range of backgrounds. Shrimp preferred dark backgrounds over light ones irrespective of their own colouration and its match with the background colour. Moreover, the brown and red morphs, in contrast to the white morph, preferred the coarse background pattern over the finer pattern. This suggests that the presence of dark, uniform substrata (e.g., rocks, macrophytes) will favour N. davidi. Nevertheless, the polymorphism of the species has little effect on its total niche breadth, and thus its invasive potential.

Fast Developmental Stereo-Disparity Detectors

2020 ◽  
Author(s):  
J. Arden Knoll ◽  
Van-Nam Hoang ◽  
Jacob Honer ◽  
Samuel Church ◽  
Thanh-Hai Tran ◽  
...  
Keyword(s):  
Stereo Disparity

scholarly journals Cortical computation of stereo disparity

1998 ◽  
Vol 38 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Niall P. McLoughlin ◽  
Stephen Grossberg
Keyword(s):  
Stereo Disparity ◽  
Cortical Computation

The Interpretation of Stereo-Disparity Information: The Computation of Surface Orientation and Depth

Perception ◽  
1982 ◽  
Vol 11 (4) ◽  
pp. 387-407 ◽  
Author(s):  
John Mayhew
Keyword(s):  
Surface Orientation ◽  
The Other ◽  
Surface Patch ◽  
Viewing Distance ◽  
Horizontal Disparity ◽  
Planar Surface ◽  
Local Surface ◽  
Stereo Disparity ◽  
The Gaze ◽  
Perceptual Phenomenon

Two methods for interpreting disparity information are described. Neither requires extraretinal information to scale for distance: one method uses horizontal disparities to solve for the viewing distance, the other uses the vertical disparities. Method 1 requires the assumption that the disparities derive from a locally planar surface. Then from the horizontal disparities measured at four retinal locations the viewing distance and the equation of local surface ‘patch’ can be obtained. Method 2 does not need this assumption. The vertical disparities are first used to obtain the values of the gaze and viewing distance. These are then used to interpret the horizontal disparity information. An algorithm implementing the methods has been tested and is found to be subject to a perceptual phenomenon known as the ‘induced effect’.

scholarly journals Hand Detection Using Cascade of Softmax Classifiers

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Yan-Guo Zhao ◽  
Feng Zheng ◽  
Zhan Song
Keyword(s):  
Logistic Regression ◽  
Real Time ◽  
Sliding Window ◽  
Detection Accuracy ◽  
Hand Posture ◽  
Hand Detection ◽  
Cascade Structure ◽  
Real Time Applications ◽  
Binary Classifiers ◽  
Background Pattern

Sliding-window based multiclass hand posture detections are often performed by detecting postures of each predefined category using an independent detector, which makes it lack efficiency and results in high postures confusion rates in real-time applications. To tackle such problems, in this work, an efficient cascade detector that integrates multiple softmax-based binary (SftB) models and a softmax-based multiclass (SftM) model is investigated to perform multiclass posture detection in parallel. The SftB models are used to distinguish the predefined postures from the background regions, and the SftM model is applied to discriminate among all the predefined hand posture categories. Another usage of the cascade structure is that it could effectively decompose the complexity of background pattern space and therefore improve the detection accuracy. In addition, to balance the detection accuracy and efficiency, the HOG features of increasing resolutions will be adopted by classifiers of increasing stage-levels in the cascade structure. The experiments are implemented under various scenarios with complicated background and challenging lightings. Results show the superiority of the proposed SftB classifiers over the traditional binary classifiers such as logistic regression, as well as the accuracy and efficiency improvements brought by the softmax-based cascade architecture compared with the noncascade multiclass softmax detectors.

scholarly journals How Do Reliability and Timing Influence Cue-Combinations for Shading and Stereo-Disparity?

i-Perception ◽  
10.1068/i185 ◽  
2011 ◽  
Vol 2 (3) ◽  
pp. 185-185
Author(s):  
P G Lovell ◽  
M Bloj ◽  
J M Harris
Keyword(s):  
Stereo Disparity
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