2,363 research outputs found
Structured Light-Based 3D Reconstruction System for Plants.
Camera-based 3D reconstruction of physical objects is one of the most popular computer vision trends in recent years. Many systems have been built to model different real-world subjects, but there is lack of a completely robust system for plants. This paper presents a full 3D reconstruction system that incorporates both hardware structures (including the proposed structured light system to enhance textures on object surfaces) and software algorithms (including the proposed 3D point cloud registration and plant feature measurement). This paper demonstrates the ability to produce 3D models of whole plants created from multiple pairs of stereo images taken at different viewing angles, without the need to destructively cut away any parts of a plant. The ability to accurately predict phenotyping features, such as the number of leaves, plant height, leaf size and internode distances, is also demonstrated. Experimental results show that, for plants having a range of leaf sizes and a distance between leaves appropriate for the hardware design, the algorithms successfully predict phenotyping features in the target crops, with a recall of 0.97 and a precision of 0.89 for leaf detection and less than a 13-mm error for plant size, leaf size and internode distance
Detection of bimanual gestures everywhere: why it matters, what we need and what is missing
Bimanual gestures are of the utmost importance for the study of motor
coordination in humans and in everyday activities. A reliable detection of
bimanual gestures in unconstrained environments is fundamental for their
clinical study and to assess common activities of daily living. This paper
investigates techniques for a reliable, unconstrained detection and
classification of bimanual gestures. It assumes the availability of inertial
data originating from the two hands/arms, builds upon a previously developed
technique for gesture modelling based on Gaussian Mixture Modelling (GMM) and
Gaussian Mixture Regression (GMR), and compares different modelling and
classification techniques, which are based on a number of assumptions inspired
by literature about how bimanual gestures are represented and modelled in the
brain. Experiments show results related to 5 everyday bimanual activities,
which have been selected on the basis of three main parameters: (not)
constraining the two hands by a physical tool, (not) requiring a specific
sequence of single-hand gestures, being recursive (or not). In the best
performing combination of modeling approach and classification technique, five
out of five activities are recognized up to an accuracy of 97%, a precision of
82% and a level of recall of 100%.Comment: Submitted to Robotics and Autonomous Systems (Elsevier
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