Step by step and frame by frame – Workflow for efficient motion tracking of high-speed movements in animals

Koehnsen, Alexander; Kambach, Jannis; Büsse, Sebastian

doi:10.1016/j.zool.2020.125800

Cited by 13 publications

(12 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Complex environmental factors in moving background, such as holes and noise, will have a negative impact on human motion [7]. e current conventional background segmentation technologies, such as background reduction algorithm, inter-frame difference algorithm, motion field algorithm based on human motion, etc., all have serious convergence and background extraction defects [8,9]. erefore, how to extract the contour of the moving object efficiently and reasonably and recognize the corresponding gait of the moving object completely is the key and hotspot of human motion tracking.…”

Section: Introductionmentioning

confidence: 99%

The Accurate Repair of Image Contour of Human Motion Tracking Based on Improved Snake Model

Feng

Gao

2021

Complexity

View full text Add to dashboard Cite

With the rapid development of sports science, human motion recognition technology, as a new biometric recognition technology, has many advantages, such as noncontact target, long recognition distance, secret recognition process, and so on. Traditional human motion recognition technology is affected by environmental factors such as motion background, which is prone to rough edges of the recognized objects and loss of motion tracking information, thus further reducing the recognition accuracy. In this paper, the traditional snake model will be improved and optimized to improve the defect of human motion model contour extraction, so as to realize the accurate repair of image contour; in terms of algorithm running time, this paper innovatively improves the construction process of the snake model, further improves the running time of model evaluation, and solves the concave contour problem of corresponding moving objects in the snake model. In order to solve the problem of accurate convergence, this paper improves the snake model of the average moving algorithm and sets the corresponding weight coefficient to distinguish the corresponding moving target background, so as to achieve the convergence of the differential concave contour. In order to verify the superiority of the improved optimized snake model, experiments are carried out in the corresponding database. The experimental results show that the contour of the moving object extracted by the improved snake model algorithm is complete and the segmentation effect is obvious. At the same time, the running speed of the whole algorithm has been significantly improved.

show abstract

Section: Introductionmentioning

confidence: 99%

The Accurate Repair of Image Contour of Human Motion Tracking Based on Improved Snake Model

Feng

Gao

2021

Complexity

View full text Add to dashboard Cite

show abstract

“…The footage was captured with a resolution of 1024 x 1024 pixels at 5400 frames per second and saved as a 16-Bit TIFF image stack. For further analysis, the prementum was tracked using Adobe After Effects CS6 (Adobe Systems Software, San José, CA, USA) according to Koehnsen et al (2020). One Tracker (Tracker A) was placed at the prementum-postmentum joint and a second tracker (Tracker B) was placed at the joint between prementum and labial palps (highlighted in figure 1 and supplementary figure 1).…”

Section: High-speed Videography and Motion Trackingmentioning

confidence: 99%

Computational fluid dynamics provide evidence for a compensatory suction feeding like effect in the predatory strike of dragonfly larvae

Koehnsen

Brede

Gorb

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Most fast-moving aquatic predators face the challenge of bow wave formation. Water in front of predator alarms or even displaces the prey. To mitigate the formation of such a bow wave, a strategy aiming at pressure reduction via suction has evolved convergently in several animal groups: compensatory suction feeding. The aquatic larvae of dragonflies and damselflies (Insecta: Odonata) are likely to face this challenge as well. They capture prey underwater using a fast-moving raptorial appendage, the so-called prehensile labial mask. Within dragonflies (Odonata: Anisoptera) two basic shapes of the prehensile labial mask have evolved, with an either flat and slender or concave distal segment. While the former is a pure grasping device, the latter is also capable of scooping up smaller prey and retaining it inside the cavity by arrays of bristle-like structures. The hydrodynamics of the prehensile labial mask was previously unknown. We used computational fluid dynamic (CFD) simulations of the distal segment of the mask, to investigate for the first time how different shapes of the mask impact their function. Our results suggest that both shapes are highly streamlined and generate a low-pressure area, likely leading to an effect analogous to the compensatory suction feeding. This might be an interesting concept for technical application in small scale grasping devices, e.g. for simple sampling mechanisms in small-sized autonomous underwater vehicles (μAUVs).

show abstract

“…Frame by frame data on the position of the prehensile labial mask was obtained from five individuals of Anax sp. using the workflow described by Koehnsen et al (42) From tracking coordinates, the angle between head capsule and postmentum, as well as prementum and postmentum were calculated for every frame. Angular velocity was calculated at every 4th frame and Data was smoothed using an 11th order polynomial (Polynomial regression using R, see also supplementary figure S1b).…”

Section: Motion Trackingmentioning

confidence: 99%

“…Energy is stored and later released, leading to an increased peak power output. For more information on the topic we suggest Haldane et al (42).…”

Section: Terminologymentioning

confidence: 99%

Hunting with catapults: the predatory strike of the dragonfly larva

Buesse

Koehnsen

Rajabi

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Dragonfly larvae capture their prey with a strongly modified -extensible-mouthpart using 9 a biomechanically unique but not yet understood mechanism. The current opinion of hydraulic 10 pressure being the driving force of the predatory strike can be refuted by our manipulation 11 experiments and reinterpretation of former studies. On this fact, we present evidence for a 12 synchronized dual-catapult system powered by two spring-loaded catapults. The power output of the 13 system exceeds generally the maximum power achievable by musculature. Energy for the movement 14 is stored by straining a resilin-containing structure at each joint and possibly the surrounding cuticle 15 which is preloaded by muscle contraction. To achieve the precise timing required to catch fast-moving 16 prey, accessory structures are used to lock and actively trigger the system, ensuring the 17 synchronisation of both catapults. As a proof of concept, we developed a bio-inspired robotic arm 18 resembling the morphology and functional principle of the extensible mouthpart. Our study elucidates 19 the predatory strike of dragonfly larvae by proposing a novel mechanism, where two synchronized 20 catapults power the ballistic movement of prey capturing in dragonfly larvaea so-called 21 synchronized dual-catapult system. Understanding this complex biomechanical system may further 22 our understanding in related fields of bio inspired robotics and biomimetics. 24One Sentence Summary: The synchronized dual-catapult, a biomechanically novel 25 mechanism for the ballistic movement of prey capturing in dragonfly larvae 26 27 Keywords: biomechanics; functional morphology; catapult system; ballistic movement; 28 power modulation; robotic arm 29 42 Cicadomorpha; 4, 6). Here a catapult-like elastic mechanism is used to perform one of the fastest 43 jumps known by using chitinised cuticle as a spring (3). The elastic protein resilin rapidly returns the 44 leg to its original shape after a jump (using the jumps energy) and allows for repeated jumping (6). 45Resilin represents an essential element of high resilience, low fatigue, and damping mechanisms in 46 arthropods (12) due to its viscoelastic properties (13). In the specific case of a catapult system, the 47 near-perfect resilience (92-97%) and a fatigue limit of over 300 million cycles (14) in combination 48 with the ability to stretch to over three times its original length and recoil to its initial state without 49 plastic deformation (15,16) become important. 51Our example here, is the predatory strike Odonata (dragonflies and damselflies) larvae use to capture 52 preythey evolved a strongly modified, extensible mouthpart called prehensile labial mask ( Fig. 1A; 53 17,18). These larvae are key predators in their freshwater habitats, hunting invertebrates as well as 54 small vertebrates like tadpoles or fish from an ambush (19). These insects can project their specialised 55 mouthpart towards the prey, enabling the larvae to hunt effectively (see supplementary movie S1; 18). 56Previous investigati...

show abstract

Step by step and frame by frame – Workflow for efficient motion tracking of high-speed movements in animals

Cited by 13 publications

References 21 publications

The Accurate Repair of Image Contour of Human Motion Tracking Based on Improved Snake Model

The Accurate Repair of Image Contour of Human Motion Tracking Based on Improved Snake Model

Computational fluid dynamics provide evidence for a compensatory suction feeding like effect in the predatory strike of dragonfly larvae

Hunting with catapults: the predatory strike of the dragonfly larva

Contact Info

Product

Resources

About