In this paper, the singularity of Euler angles rotation representation in robot pose estimation i... more In this paper, the singularity of Euler angles rotation representation in robot pose estimation is overcome. This is accomplished through coordinate system rotating and signadjusting of the intrinsic parameter camera matrices. A stereo pair is attached to the robot and the extended Kalman filter is used as a recursive pose estimator. An extensive set of synthetic and real experiments have been carried out under various motion patterns in both singular and nonsingular settings. The approach has proved accurate in face of singularity and stable during Jacobian calculations as well.
This experiment was carried out during the two growing seasons 2012/2013 and 2013/2014 at the exp... more This experiment was carried out during the two growing seasons 2012/2013 and 2013/2014 at the experimental farm of Unit for Strawberry and Non Traditional Horticulture Crops, Horticulture Department, Faculty of Agriculture, Ain Shams University, Egypt, in order to investigate the effect of magnetic field on germination of true potato seeds (TPS), vegetative growth and potato tubers characteristics of potato plants “cv. Spunta”. The true potato seeds were exposed to three magnetic field strengths: 20-30-40 mT for three periods: 5, 10 and 15 minutes compared to untreated true potato seeds (control). Results indicated that, magnetic field treatments significantly increased the germination percentage of true potato seeds, vegetative growth parameters and improved potato tubers characteristics. Where, true potato seeds were exposed to 30 mT (magnetic strength) for 10 minutes produced the highest significant values of germination percentage, plant length, number of leaves per plant, fruit...
In this work, we solve the pose estimation problem for robot motion by placing multiple cameras o... more In this work, we solve the pose estimation problem for robot motion by placing multiple cameras on the robot. In particular, we use four cameras arranged as two back-to-back stereo pairs combined with the extended Kalman filter (EKF). The reason for using multiple cameras is that the pose estimation problem is more constrained for multiple cameras than for a single camera. Back-to-back cameras are used since they provide more information. Stereo information is used in self initialization and outlier rejection. Different approaches to solve the long-sequence-drift have been suggested. Both the simulations and the real experiments show that our approach is fast, robust, and accurate.
For more than half a century, the Hough transform is everexpanding for new frontiers. Thousands o... more For more than half a century, the Hough transform is everexpanding for new frontiers. Thousands of research papers and numerous applications have evolved over the decades. Carrying out an all-inclusive survey is hardly possible and enormously space-demanding. What we care about here is emphasizing some of the most crucial milestones of the transform. We describe its variations elaborating on the basic ones such as the line and circle Hough transforms. The high demand for storage and computation time is clarified with different solution approaches. Since most uses of the transform take place on binary images, we have been concerned with the work done directly on gray or color images. The myriad applications of the standard transform and its variations have been classified highlighting the up-to-date and the unconventional ones. Due to its merits such as noise-immunity and expandability, the transform has an excellent history, and a bright future as well.
The analysis of frame sequences in talk show videos, which is necessary for media mining and tele... more The analysis of frame sequences in talk show videos, which is necessary for media mining and television production, requires significant manual efforts and is a very time-consuming process. Given the vast amount of unlabeled face frames from talk show videos, we address and propose a solution to the problem of recognizing and clustering faces. In this paper, we propose a TV media mining system that is based on a deep convolutional neural network approach, which has been trained with a triplet loss minimization method. The main function of the proposed system is the indexing and clustering of video data for achieving an effective media production analysis of individuals in talk show videos and rapidly identifying a specific individual in video data in real-time processing. Our system uses several face datasets from Labeled Faces in the Wild (LFW), which is a collection of unlabeled web face images, as well as YouTube Faces and talk show faces datasets. In the recognition (person spot...
A multilevel security (MLS) is a familiar scheme of classification in the national security hiera... more A multilevel security (MLS) is a familiar scheme of classification in the national security hierarchy, which partitions subjects into levels such as secret, top-secret, confidential, and unclassified. These networks may combine several security levels such as message digest, data compression, encryption, and smart card technology, respectively. These levels can work together to establish top security services such as data integrity,
Proceedings Icip International Conference on Image Processing, Oct 1, 2008
The Extended Kalman Filter (EKF) is suitable for real-time pose es- timation due its low computat... more The Extended Kalman Filter (EKF) is suitable for real-time pose es- timation due its low computational demand and ability to handle the nonlinear perspective camera model. There are many EKF based ap- proaches in the literature; some are very recent while others exist for about two decades. These methods differ in two main aspects: the number and arrangement of cameras,
We study the use of overlapping and non-overlapping camera layouts in estimating the ego-motion o... more We study the use of overlapping and non-overlapping camera layouts in estimating the ego-motion of a moving robot. To estimate the location and orientation of the robot, we investigate using four cameras as non-overlapping individuals, and as two stereo pairs. The pros and cons of the two approaches are elucidated. The cameras work independently and can have larger field of view in the non-overlapping layout. However, a scale factor ambiguity should be dealt with. On the other hand, stereo systems provide more accuracy but require establishing feature correspondence with more computational demand. For both approaches, the extended Kalman filter is used as a real-time recursive estimator. The approaches studied are verified with synthetic and real experiments alike.
Proceedings Icip International Conference on Image Processing, Sep 1, 2010
In this paper, we solve the pose estimation problem in real time using multiple nonoverlapping ca... more In this paper, we solve the pose estimation problem in real time using multiple nonoverlapping cameras and the Extended Kalman Filter (EKF). Four cameras arranged in two back-to-back pairs are put on the platform of a moving robot. The two axes passing through the camera centers of each pair are perpendicular. This arrangement aims to maximize the benefits of the
In this paper, we study the effect of the layout of multiple cameras placed on top of an autonomo... more In this paper, we study the effect of the layout of multiple cameras placed on top of an autonomous mobile robot. The idea is to study the effect of camera layout on the accuracy of estimated pose parameters. Particularly, we compare the performance of a vertical-stereo-pair put on the robot at the axis of rotation to that of a horizontal-stereo-pair. The motivation behind this comparison is that the robot rotation causes only a change of orientation to the cameras on the axis of rotation. On the other hand, off-axis cameras encounter additional translation beside the change of orientation. In this work, we show that for a stereo pair encountering sequences of large rotations, at least a reference camera should be put on the axis of rotation. Otherwise, the obtained translations have to be corrected based on the location of the rotation axis. This finding will help robot designers to develop vision systems that are capable of obtaining accurate pose for navigation control. An extens...
For more than half a century, the Hough transform is ever-expanding for new frontiers. Thousands ... more For more than half a century, the Hough transform is ever-expanding for new frontiers. Thousands of research papers and numerous applications have evolved over the decades. Carrying out an all-inclusive survey is hardly possible and enormously space-demanding. What we care about here is emphasizing some of the most crucial milestones of the transform. We describe its variations elaborating on the basic ones such as the line and circle Hough transforms. The high demand for storage and computation time is clarified with different solution approaches. Since most uses of the transform take place on binary images, we have been concerned with the work done directly on gray or color images. The myriad applications of the standard transform and its variations have been classified highlighting the up-to-date and the unconventional ones. Due to its merits such as noise-immunity and expandability, the transform has an excellent history, and a bright future as well.
In this paper, the singularity of Euler angles rotation representation in robot pose estimation i... more In this paper, the singularity of Euler angles rotation representation in robot pose estimation is overcome. This is accomplished through coordinate system rotating and signadjusting of the intrinsic parameter camera matrices. A stereo pair is attached to the robot and the extended Kalman filter is used as a recursive pose estimator. An extensive set of synthetic and real experiments have been carried out under various motion patterns in both singular and nonsingular settings. The approach has proved accurate in face of singularity and stable during Jacobian calculations as well.
This experiment was carried out during the two growing seasons 2012/2013 and 2013/2014 at the exp... more This experiment was carried out during the two growing seasons 2012/2013 and 2013/2014 at the experimental farm of Unit for Strawberry and Non Traditional Horticulture Crops, Horticulture Department, Faculty of Agriculture, Ain Shams University, Egypt, in order to investigate the effect of magnetic field on germination of true potato seeds (TPS), vegetative growth and potato tubers characteristics of potato plants “cv. Spunta”. The true potato seeds were exposed to three magnetic field strengths: 20-30-40 mT for three periods: 5, 10 and 15 minutes compared to untreated true potato seeds (control). Results indicated that, magnetic field treatments significantly increased the germination percentage of true potato seeds, vegetative growth parameters and improved potato tubers characteristics. Where, true potato seeds were exposed to 30 mT (magnetic strength) for 10 minutes produced the highest significant values of germination percentage, plant length, number of leaves per plant, fruit...
In this work, we solve the pose estimation problem for robot motion by placing multiple cameras o... more In this work, we solve the pose estimation problem for robot motion by placing multiple cameras on the robot. In particular, we use four cameras arranged as two back-to-back stereo pairs combined with the extended Kalman filter (EKF). The reason for using multiple cameras is that the pose estimation problem is more constrained for multiple cameras than for a single camera. Back-to-back cameras are used since they provide more information. Stereo information is used in self initialization and outlier rejection. Different approaches to solve the long-sequence-drift have been suggested. Both the simulations and the real experiments show that our approach is fast, robust, and accurate.
For more than half a century, the Hough transform is everexpanding for new frontiers. Thousands o... more For more than half a century, the Hough transform is everexpanding for new frontiers. Thousands of research papers and numerous applications have evolved over the decades. Carrying out an all-inclusive survey is hardly possible and enormously space-demanding. What we care about here is emphasizing some of the most crucial milestones of the transform. We describe its variations elaborating on the basic ones such as the line and circle Hough transforms. The high demand for storage and computation time is clarified with different solution approaches. Since most uses of the transform take place on binary images, we have been concerned with the work done directly on gray or color images. The myriad applications of the standard transform and its variations have been classified highlighting the up-to-date and the unconventional ones. Due to its merits such as noise-immunity and expandability, the transform has an excellent history, and a bright future as well.
The analysis of frame sequences in talk show videos, which is necessary for media mining and tele... more The analysis of frame sequences in talk show videos, which is necessary for media mining and television production, requires significant manual efforts and is a very time-consuming process. Given the vast amount of unlabeled face frames from talk show videos, we address and propose a solution to the problem of recognizing and clustering faces. In this paper, we propose a TV media mining system that is based on a deep convolutional neural network approach, which has been trained with a triplet loss minimization method. The main function of the proposed system is the indexing and clustering of video data for achieving an effective media production analysis of individuals in talk show videos and rapidly identifying a specific individual in video data in real-time processing. Our system uses several face datasets from Labeled Faces in the Wild (LFW), which is a collection of unlabeled web face images, as well as YouTube Faces and talk show faces datasets. In the recognition (person spot...
A multilevel security (MLS) is a familiar scheme of classification in the national security hiera... more A multilevel security (MLS) is a familiar scheme of classification in the national security hierarchy, which partitions subjects into levels such as secret, top-secret, confidential, and unclassified. These networks may combine several security levels such as message digest, data compression, encryption, and smart card technology, respectively. These levels can work together to establish top security services such as data integrity,
Proceedings Icip International Conference on Image Processing, Oct 1, 2008
The Extended Kalman Filter (EKF) is suitable for real-time pose es- timation due its low computat... more The Extended Kalman Filter (EKF) is suitable for real-time pose es- timation due its low computational demand and ability to handle the nonlinear perspective camera model. There are many EKF based ap- proaches in the literature; some are very recent while others exist for about two decades. These methods differ in two main aspects: the number and arrangement of cameras,
We study the use of overlapping and non-overlapping camera layouts in estimating the ego-motion o... more We study the use of overlapping and non-overlapping camera layouts in estimating the ego-motion of a moving robot. To estimate the location and orientation of the robot, we investigate using four cameras as non-overlapping individuals, and as two stereo pairs. The pros and cons of the two approaches are elucidated. The cameras work independently and can have larger field of view in the non-overlapping layout. However, a scale factor ambiguity should be dealt with. On the other hand, stereo systems provide more accuracy but require establishing feature correspondence with more computational demand. For both approaches, the extended Kalman filter is used as a real-time recursive estimator. The approaches studied are verified with synthetic and real experiments alike.
Proceedings Icip International Conference on Image Processing, Sep 1, 2010
In this paper, we solve the pose estimation problem in real time using multiple nonoverlapping ca... more In this paper, we solve the pose estimation problem in real time using multiple nonoverlapping cameras and the Extended Kalman Filter (EKF). Four cameras arranged in two back-to-back pairs are put on the platform of a moving robot. The two axes passing through the camera centers of each pair are perpendicular. This arrangement aims to maximize the benefits of the
In this paper, we study the effect of the layout of multiple cameras placed on top of an autonomo... more In this paper, we study the effect of the layout of multiple cameras placed on top of an autonomous mobile robot. The idea is to study the effect of camera layout on the accuracy of estimated pose parameters. Particularly, we compare the performance of a vertical-stereo-pair put on the robot at the axis of rotation to that of a horizontal-stereo-pair. The motivation behind this comparison is that the robot rotation causes only a change of orientation to the cameras on the axis of rotation. On the other hand, off-axis cameras encounter additional translation beside the change of orientation. In this work, we show that for a stereo pair encountering sequences of large rotations, at least a reference camera should be put on the axis of rotation. Otherwise, the obtained translations have to be corrected based on the location of the rotation axis. This finding will help robot designers to develop vision systems that are capable of obtaining accurate pose for navigation control. An extens...
For more than half a century, the Hough transform is ever-expanding for new frontiers. Thousands ... more For more than half a century, the Hough transform is ever-expanding for new frontiers. Thousands of research papers and numerous applications have evolved over the decades. Carrying out an all-inclusive survey is hardly possible and enormously space-demanding. What we care about here is emphasizing some of the most crucial milestones of the transform. We describe its variations elaborating on the basic ones such as the line and circle Hough transforms. The high demand for storage and computation time is clarified with different solution approaches. Since most uses of the transform take place on binary images, we have been concerned with the work done directly on gray or color images. The myriad applications of the standard transform and its variations have been classified highlighting the up-to-date and the unconventional ones. Due to its merits such as noise-immunity and expandability, the transform has an excellent history, and a bright future as well.
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Papers by Mohammad Ragab