Limits...
A Novel Method for Tracking Individuals of Fruit Fly Swarms Flying in a Laboratory Flight Arena.

Cheng XE, Qian ZM, Wang SH, Jiang N, Guo A, Chen YQ - PLoS ONE (2015)

Bottom Line: We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases.Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance.Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment.

View Article: PubMed Central - PubMed

Affiliation: School of Computer Science, Shanghai Key Laboratory of Intelligent Information Processing, Fudan University, Shanghai, China; Jingdezhen Ceramic Institute, Jingdezhen, China.

ABSTRACT
The growing interest in studying social behaviours of swarming fruit flies, Drosophila melanogaster, has heightened the need for developing tools that provide quantitative motion data. To achieve such a goal, multi-camera three-dimensional tracking technology is the key experimental gateway. We have developed a novel tracking system for tracking hundreds of fruit flies flying in a confined cubic flight arena. In addition to the proposed tracking algorithm, this work offers additional contributions in three aspects: body detection, orientation estimation, and data validation. To demonstrate the opportunities that the proposed system offers for generating high-throughput quantitative motion data, we conducted experiments on five experimental configurations. We also performed quantitative analysis on the kinematics and the spatial structure and the motion patterns of fruit fly swarms. We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases. Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance. Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment.

No MeSH data available.


Related in: MedlinePlus

Orientation computation.(a) The geometric interpretation of the orientation computation. Here I1 and I2 denotes the image plane of Camera 1(red) and Camera 2(blue) respectively. The line-segment (red) denotes the ellipse’s major axis in I1. And the line-segment (blue) denotes the ellipse’s major axis in I2. The projection rays of those end-points define two plane Φ1 and Φ2 respectively, e.g. two red rays define Φ1. The orientation  can be computed from the direction of the cross line (the longer green line-segment) between two planes Φ1 and Φ2. All definitions are defined in the world coordinate system. (b) The problematic orientation computation. The measurement is drawn in red, and red dashed lines are the major-axis and minor-axis of its ellipse. A generative shape according to the particle state  is re-projected into Camera 2 (see S2 Fig, the generative shape model). The green pixels are re-projected pixels and the yellow pixels are identical pixels. (c) The error ϵ as a function of the ratio γ. Here γ defines the length ration between the major-axis and the minor-axis of an ellipse.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4470659&req=5

pone.0129657.g005: Orientation computation.(a) The geometric interpretation of the orientation computation. Here I1 and I2 denotes the image plane of Camera 1(red) and Camera 2(blue) respectively. The line-segment (red) denotes the ellipse’s major axis in I1. And the line-segment (blue) denotes the ellipse’s major axis in I2. The projection rays of those end-points define two plane Φ1 and Φ2 respectively, e.g. two red rays define Φ1. The orientation can be computed from the direction of the cross line (the longer green line-segment) between two planes Φ1 and Φ2. All definitions are defined in the world coordinate system. (b) The problematic orientation computation. The measurement is drawn in red, and red dashed lines are the major-axis and minor-axis of its ellipse. A generative shape according to the particle state is re-projected into Camera 2 (see S2 Fig, the generative shape model). The green pixels are re-projected pixels and the yellow pixels are identical pixels. (c) The error ϵ as a function of the ratio γ. Here γ defines the length ration between the major-axis and the minor-axis of an ellipse.

Mentions: Measurements defined by form an MMP (c.f. There may probably be more than one MMP. Please see Fig 4, the legend.). An MMP includes one measurement in each camera view. The ellipses of the MMP are employed to compute the target’s orientation according to the pinhole camera model in Euclid geometry. The geometric interpretation of computing the orientation is shown in Fig 5a.


A Novel Method for Tracking Individuals of Fruit Fly Swarms Flying in a Laboratory Flight Arena.

Cheng XE, Qian ZM, Wang SH, Jiang N, Guo A, Chen YQ - PLoS ONE (2015)

Orientation computation.(a) The geometric interpretation of the orientation computation. Here I1 and I2 denotes the image plane of Camera 1(red) and Camera 2(blue) respectively. The line-segment (red) denotes the ellipse’s major axis in I1. And the line-segment (blue) denotes the ellipse’s major axis in I2. The projection rays of those end-points define two plane Φ1 and Φ2 respectively, e.g. two red rays define Φ1. The orientation  can be computed from the direction of the cross line (the longer green line-segment) between two planes Φ1 and Φ2. All definitions are defined in the world coordinate system. (b) The problematic orientation computation. The measurement is drawn in red, and red dashed lines are the major-axis and minor-axis of its ellipse. A generative shape according to the particle state  is re-projected into Camera 2 (see S2 Fig, the generative shape model). The green pixels are re-projected pixels and the yellow pixels are identical pixels. (c) The error ϵ as a function of the ratio γ. Here γ defines the length ration between the major-axis and the minor-axis of an ellipse.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4470659&req=5

pone.0129657.g005: Orientation computation.(a) The geometric interpretation of the orientation computation. Here I1 and I2 denotes the image plane of Camera 1(red) and Camera 2(blue) respectively. The line-segment (red) denotes the ellipse’s major axis in I1. And the line-segment (blue) denotes the ellipse’s major axis in I2. The projection rays of those end-points define two plane Φ1 and Φ2 respectively, e.g. two red rays define Φ1. The orientation can be computed from the direction of the cross line (the longer green line-segment) between two planes Φ1 and Φ2. All definitions are defined in the world coordinate system. (b) The problematic orientation computation. The measurement is drawn in red, and red dashed lines are the major-axis and minor-axis of its ellipse. A generative shape according to the particle state is re-projected into Camera 2 (see S2 Fig, the generative shape model). The green pixels are re-projected pixels and the yellow pixels are identical pixels. (c) The error ϵ as a function of the ratio γ. Here γ defines the length ration between the major-axis and the minor-axis of an ellipse.
Mentions: Measurements defined by form an MMP (c.f. There may probably be more than one MMP. Please see Fig 4, the legend.). An MMP includes one measurement in each camera view. The ellipses of the MMP are employed to compute the target’s orientation according to the pinhole camera model in Euclid geometry. The geometric interpretation of computing the orientation is shown in Fig 5a.

Bottom Line: We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases.Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance.Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment.

View Article: PubMed Central - PubMed

Affiliation: School of Computer Science, Shanghai Key Laboratory of Intelligent Information Processing, Fudan University, Shanghai, China; Jingdezhen Ceramic Institute, Jingdezhen, China.

ABSTRACT
The growing interest in studying social behaviours of swarming fruit flies, Drosophila melanogaster, has heightened the need for developing tools that provide quantitative motion data. To achieve such a goal, multi-camera three-dimensional tracking technology is the key experimental gateway. We have developed a novel tracking system for tracking hundreds of fruit flies flying in a confined cubic flight arena. In addition to the proposed tracking algorithm, this work offers additional contributions in three aspects: body detection, orientation estimation, and data validation. To demonstrate the opportunities that the proposed system offers for generating high-throughput quantitative motion data, we conducted experiments on five experimental configurations. We also performed quantitative analysis on the kinematics and the spatial structure and the motion patterns of fruit fly swarms. We found that there exists an asymptotic distance between fruit flies in swarms as the population density increases. Further, we discovered the evidence for repulsive response when the distance between fruit flies approached the asymptotic distance. Overall, the proposed tracking system presents a powerful method for studying flight behaviours of fruit flies in a three-dimensional environment.

No MeSH data available.


Related in: MedlinePlus