scholarly journals OpenEyeSim 2.0: Simulation of accommodation, depth-of-field, chromatic aberration, and contrast sensitivity in a biomechanical model of the oculomotor system

2021 ◽  
Vol 21 (9) ◽  
pp. 2280
Author(s):  
Alexander Lichtenstein ◽  
Jochen Triesch
1999 ◽  
Vol 5 (S2) ◽  
pp. 186-187
Author(s):  
Joanita Jakarta ◽  
Wah Chiu

Three-dimensional structure studies provide important information about the organization of macromolecules, often revealing biological mechanisms and protein structure-function relationships. 400 KV electron cryo-microscopy is an emerging technology that is proving to be a powerful tool for studying the structures of large macromolecular assemblies that are often not tractable using other techniques. Its large depth of field makes it well-suited for imaging large objects to high resolution. In addition, a high accelerating voltage minimizes chromatic aberration yielding images of higher contrast. Recently a 400 KV electron cryo-microscope has been used to image periodic arrays of tubulin to 3.5 Å and single particles at somewhat lower resolutions (13 Å) providing practical demonstrations of its usefulness in modern structural biology. In this paper we present high resolution image data of two large icosahedral viruses: herpes simplex virus IB nucleocapsid (HSV IB) and rice dwarf virus (RDV). Human herpes virus (HSV) is associated with a spectrum of diseases ranging from cold sores to more severe clinical manifestations such as mental retardation.


2017 ◽  
Author(s):  
Lukas Klimmasch ◽  
Alexander Lelais ◽  
Alexander Lichtenstein ◽  
Bertram E. Shi ◽  
Jochen Triesch

AbstractWe present a model for the autonomous learning of active binocular vision using a recently developed biome-chanical model of the human oculomotor system. The model is formulated in the Active Efficient Coding (AEC) framework, a recent generalization of classic efficient coding theories to active perception. The model simultaneously learns how to efficiently encode binocular images and how to generate accurate vergence eye movements that facilitate efficient encoding of the visual input. In order to resolve the redundancy problem arising from the actuation of the eyes through antagonistic muscle pairs, we consider the metabolic costs associated with eye movements. We show that the model successfully learns to trade off vergence accuracy against the associated metabolic costs, producing high fidelity vergence eye movements obeying Sherrington’s law of reciprocal innervation.


2020 ◽  
Author(s):  
Jiaojiao Liu ◽  
Yuhu Li ◽  
Huiping Xing ◽  
Daodao Hu ◽  
Xiaolian Chao ◽  
...  

Abstract As a kind of textile, hemp artifact is a valuable cultural heritage. Suffering from several degradation factors in the preservation of cultural relics, some ancient hemp colored-paintings have been damaged, further affected their ornamental values. Therefore, it is urged to take the suitable conservation measures to protect the precious hemp artifacts for the historical culture succession. In this paper, an examination and analysis of the hemp colored paintings were the first step to propose an appropriate conservation treatment. Ultra-depth-of-field microscope was used to identify the kinds of fiber, and scanning electron microscope (SEM) was utilized to observe their condition and surface morphology. The element distribution and composition were identified by SEM, energy disperse spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF). Gas chromatography-mass spectrometer (GC-MS) was applied to identify the kinds of binding media and amino acid composition. Moreover, novel reinforcement materials and technology were proposed with the principle of compatibility and feasibility. The properties of tensile strength, aging resistance and chromatic aberration were tested before and after dry heat aging, wet heat aging and UV light aging. After systematic examination and evaluation of the hemp colored paintings and reinforcement materials, the optimal conservation treatment was finally established, and the Chinese hemp painting as an example has been protected successfully. This paper provides new methods and ideas for the restoration and protection of the linen cultural relics, which would promote the progress of protecting valuable cultural heritages.


2016 ◽  
Vol 36 (6) ◽  
pp. 657-663 ◽  
Author(s):  
Mateusz Jaskulski ◽  
Iván Marín-Franch ◽  
Paula Bernal-Molina ◽  
Norberto López-Gil

2017 ◽  
Vol 25 (25) ◽  
pp. 31696 ◽  
Author(s):  
Niamh M. Fitzgerald ◽  
Christopher Dainty ◽  
Alexander V. Goncharov

Author(s):  
E. Paiz-Reyes ◽  
M. Brédif ◽  
S. Christophe

Abstract. Archivists, historians and national mapping agencies, among others, are archiving large datasets of historical photographs. Nevertheless, the capturing devices used to acquire these images possessed a diversity of effects that influenced the quality of the final resulting picture, e.g. geometric distortion, chromatic aberration, depth of field variation, etc. This paper examines singularly the topic of geometric distortion for a co-visualization of historical photos within a 3D model of the photographed scene. A distortion function of an image is ordinarily estimated only on the image domain by adjusting its parameters to observations of point correspondences. This mathematical function may exhibit overfits, oscillations or may not be well defined outside of this domain. The contribution of this work is the description of a distortion model defined on the whole undistorted image plane. We extrapolate the distortion estimated only on the image domain and then transfer this distortion information to the view of the 3D scene. This enables to look at the scene through an estimated camera and zoom out to see the context around the original photograph with a well-defined and behaved distortion. These findings may be a significant addition to the overall purpose of creating innovative ways to examine and visualize old photographs.


2018 ◽  
Vol 74 (3/2018) ◽  
pp. 85-89
Author(s):  
Vlasák Ondřej ◽  
Jiřina Škorpíková ◽  
Zuzana Hlinomazová ◽  
Věra Kalandrová

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