Search results for "edge detection"
showing 10 items of 43 documents
Simulated raindrop's characteristic measurements. A new approach of image processing tested under laboratory rainfall simulation
2018
Abstract The size of the drops determines soil erosion and runoff rates, and then the fate of ecosystems. Various raindrop measurement techniques and tools have been developed to determine natural and simulated raindrop size distributions and mean drop size. There is a need to improve the procedure to determine the raindrop properties, and this is why we develop a new technique to analyze drop size distribution and fall velocity. For this purpose a rainfall simulator with two oscillating Veejet 80100 nozzles in laboratory condition, and high speed imaging technique and edge detection approach in image processing was applied to identify and measure drop size and calculate drop velocity. The …
<title>Architecture for real-time wood inspection</title>
2000
This study has been realized to improve industrial machines that allow to analyze planks by detecting their width and too important defects thanks to a computer vision system. These machines are currently piloted by software with the help of PCs. The aim of our work is to realize a hardware card to increase the processing speed.
Time-resolved velocity measurements in a magnetic micromixer
2015
Abstract Mixing efficiency is lower in passive micromixers due to viscous forces and substantial research effort is focused on designing high performance micromixers. Active micromixers make use of external forces to enhance mixing efficiency. Among these, magnetic forces are popular because they are non-contact and therefore the micromixer design can be kept simple. Laser-based diagnostic tools have great potential in providing multi-parameter information in microfluidics research on mixing. MicroPIV experiments are performed to investigate the transient flow field in a magnetic micromixer undergoing labyrinthine instability. Velocity and interface front information is extracted from a seq…
A Specialized Architecture for Color Image Edge Detection Based on Clifford Algebra
2013
Edge detection of color images is usually performed by applying the traditional techniques for gray-scale images to the three color channels separately. However, human visual perception does not differentiate colors and processes the image as a whole. Recently, new methods have been proposed that treat RGB color triples as vectors and color images as vector fields. In these approaches, edge detection is obtained extending the classical pattern matching and convolution techniques to vector fields. This paper proposes a hardware implementation of an edge detection method for color images that exploits the definition of geometric product of vectors given in the Clifford algebra framework to ex…
Hypergraph imaging: an overview
2002
Hypergraph theory as originally developed by Berge (Hypergraphe, Dunod, Paris, 1987) is a theory of finite combinatorial sets, modeling lot of problems of operational research and combinatorial optimization. This framework turns out to be very interesting for many other applications, in particular for computer vision. In this paper, we are going to survey the relationship between combinatorial sets and image processing. More precisely, we propose an overview of different applications from image hypergraph models to image analysis. It mainly focuses on the combinatorial representation of an image and shows the effectiveness of this approach to low level image processing; in particular to seg…
A non-parametric Scale-based Corner Detector
2008
This paper introduces a new Harris-affine corner detector algorithm, that does not need parameters to locate corners in images, given an observation scale. Standard detectors require to fine tune the values of parameters which strictly depend on the particular input image. A quantitative comparison between our implementation and a standard Harris-affine implementation provides good results, showing that the proposed methodology is robust and accurate. The benchmark consists of public images used in literature for feature detection.
A Trusted Hybrid Learning Approach to Secure Edge Computing
2021
Securing edge computing has drawn much attention due to the vital role of edge computing in Fifth Generation (5G) wireless networks. Artificial Intelligence (AI) has been adopted to protect networks against attackers targeting the connected edge devices or the wireless channel. However, the proposed detection mechanisms could generate a high false detection rate, especially against unknown attacks defined as zero-day threats. Thereby, we propose and conceive a new hybrid learning security framework that combines the expertise of security experts and the strength of machine learning to protect the edge computing network from known and unknown attacks, while minimizing the false detection rat…
A local level set method for liver segmentation in functional MR imaging
2011
Functional Magnetic Resonance (fMR) is a medical image technique in which a contrast is injected in the vascular system so that blood diffusion along it can be observed as variations of the signal intensity. The uptake variations of the contrast agent are used in early detection of tumorous tissue. For the diagnostic to be accurate, successive volumes must be correctly registered. For binary registration prior segmentation of the 3D fMR data is required. Here we present a local 3D level-set segmentation method which preserves details and edges, along with its multi-scale version which has the advantage of a great acceleration with respect to the single-scale version. Results of liver segmen…
Shift- and scale-invariant recognition of contour objects with logarithmic radial harmonic filters.
2008
The phase-only logarithmic radial harmonic (LRH) filter has been shown to be suitable for scale-invariant block object recognition. However, an important set of objects is the collection of contour functions that results from a digital edge extraction of the original block objects. These contour functions have a constant width that is independent of the scale of the original object. Therefore, since the energy of the contour objects decreases more slowly with the scale factor than does the energy of the block objects, the phase-only LRH filter has difficulties in the recognition tasks when these contour objects are used. We propose a modified LRH filter that permits the realization of a shi…
Mathematical Morphology Based on Fuzzy Operators
1993
A vision procedure may be considered as the repeated application of image operators until the vision goal is reached. The type of these operators and the spaces on which they are defined and act depends on the specific problem and on what we are searching on the image. Morphological operations, as filtering, edge detection, skeletonizing, and so on, are mainly required at low and medium levels of the vision procedure, where local and global knowledge is used to enhance the image information content, before a final decision about the image is taken.