Image Rotation

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 3924 Experts worldwide ranked by ideXlab platform

T. Srikanthan - One of the best experts on this subject based on the ideXlab platform.

  • Techniques for area-time efficient Image Rotation
    2009 IEEE International Symposium on Circuits and Systems, 2009
    Co-Authors: R. K. Satzoda, S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation is a necessary task in many vision based applications. Most available Image Rotation architectures are serial in nature, while the existing parallel techniques suffer from computational bottlenecks, limiting their performance. In this paper, we propose techniques that not only speed up the Rotation process but also reduce area, yielding an area-time efficient architecture. They exploit properties of symmetry in Image coordinates for parallel Image Rotation. We show that the number of computations, the total computation time and area cost of the proposed architecture are lesser by as much as 80%, 55% and 67% respectively when compared to the most efficient parallel architecture in recent literature.

  • ISCAS - Techniques for area-time efficient Image Rotation
    2009 IEEE International Symposium on Circuits and Systems, 2009
    Co-Authors: R. K. Satzoda, S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation is a necessary task in many vision based applications. Most available Image Rotation architectures are serial in nature, while the existing parallel techniques suffer from computational bottlenecks, limiting their performance. In this paper, we propose techniques that not only speed up the Rotation process but also reduce area, yielding an area-time efficient architecture. They exploit properties of symmetry in Image coordinates for parallel Image Rotation. We show that the number of computations, the total computation time and area cost of the proposed architecture are lesser by as much as 80%, 55% and 67% respectively when compared to the most efficient parallel architecture in recent literature.

  • ICIP - High-throughput Image Rotation using sign-prediction based redundant CORDIC algorithm
    2004 International Conference on Image Processing 2004. ICIP '04., 2004
    Co-Authors: S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation forms a core operation in many applications such as medical Image processing and computer vision. High-throughput computations for Image Rotation are a common requirement in real-time Image processing. A VLSI design for Image Rotation that employs CORDIC was discussed in Ghosh et al. (1994). In this paper, we propose novel techniques to increase the throughput of the CORDIC computations, thereby notably improving the overall performance of the Rotation unit with acceptable increase in VLSI area. An efficient sign-prediction method called BTSP (Binary-Tree based Sign Prediction) is proposed in our redundant CORDIC system to eliminate the sign detection process. Our investigations show that the BTSP based CORDIC algorithm for realtime Rotation of a 512/spl times/512-pixel Image, has a significant speed-up over existing redundant CORDIC methods with reduced hardware area.

C. Milan - One of the best experts on this subject based on the ideXlab platform.

  • Real Time Image Rotation Using Dynamic Reconfiguration
    Real-time Imaging, 2002
    Co-Authors: E. Bourennane, M. Paindavoine, C. Milan, Sophie Bouchoux
    Abstract:

    Abstract Field programmable gate array (FPGA) components are widely used nowdays to implement various algorithms, such as digital filtering, in real time. The emergence of dynamically reconfigurable FPGAs made it possible to reduce the number of necessary resources to carry out an Image-processing task (tasks chain). In this article, an Image-processing application, Image Rotation, that exploits the FPGAs dynamic reconfiguration method is presented. This paper shows that the choice of an implementation, static or dynamic reconfiguration, depends on the nature of the application. A comparison is carried out between the dynamic and the static reconfiguration using two criteria: cost and performance. It appears that, according to the nature of the application, the dynamic reconfiguration can be less or more advantageous. In order to be able to test the validity of our approach in terms of algorithm and architecture adequacy, we realized an AT40K40-based board “ARDOISE”.

  • ICIP (3) - Implementation of a real time Image Rotation using B-spline interpolation on FPGA's board
    Proceedings 1998 International Conference on Image Processing. ICIP98 (Cat. No.98CB36269), 1998
    Co-Authors: C. Berthaud, E. Bourennane, M. Paindavoine, C. Milan
    Abstract:

    The aim of our work is to realize the implementation of a real-time high-quality Image Rotation on FPGA's board. The method we used is based on M. Unser's work (1993) and consists in applying a B-spline interpolator. The difficulty of this problem is due to the relatively weak integration capacity of FPGAs. To solve this problem, we have searched for determining the minimum number of bits to code the filter while keeping a good accuracy on filtering output. In this article, we remind a few definitions about B-spline functions and we present how we use B-spline interpolation for the Image Rotation problem. Then, we describe the way we calculate probability density function of the output error in order to determine the filter data coding.

  • Real-time Image Rotation using B-spline interpolation on FPGA's board
    Advanced Signal Processing Algorithms Architectures and Implementations VIII, 1998
    Co-Authors: C. Berthaud, E. Bourennane, M. Paindavoine, C. Milan
    Abstract:

    The aim of our work is to realize the implementation of a real-time high-quality Image Rotation on FPGA's board. The method we used is based on M. Unser's work and consists in applying a B-spline interpolator. The difficulty of this problem is due to the relatively weak integration capacity of FPGAs. To solve this problem we have searched for determining the minimum number of bits to code the filter while keeping a good accuracy of filtering output. In this article, we remind a few definitions about B-spline functions and we present how we use B- spline interpolation for the Image Rotation problem. Then, we describe the way we calculate probability density function of the output error in order to determine the filter data coding.

  • EUSIPCO - Real time Image Rotation using B-spline interpolation on FPGA's board
    1998
    Co-Authors: C. Berthaud, E. Bourennane, M. Paindavoine, C. Milan
    Abstract:

    The aim of our work is to realize the implementation of a real-time Image Rotation on FPGA's board. The method we used is based on a B-spline interpolator. The integration capicity of FPGAs is relatively weak, so the difficulty in this problem is to determine the right coding of the Rotation filter while keeping a good accuracy on filtering output. In this article, we remind a few definitions about B-spline functions and we present how we use B-spline interpolation for the Image Rotation problem. Then, we describe the way we calculate probability density function of the output error in order to determine the filter data coding.

  • Real-time Image Rotation on FPGA's board
    ICSP '98. 1998 Fourth International Conference on Signal Processing (Cat. No.98TH8344), 1998
    Co-Authors: C. Berthaud, E. Bourennane, M. Paindavoine, C. Milan
    Abstract:

    The aim of this work is to realize the implementation of real-time high-quality Image Rotation on an FPGA board. The method we use is based on the work of Unser et al. (1993) and consists in applying a B-spline interpolator. The difficulty of this problem is due to the large number of operations needed to implement this solution on FPGAs which have a relatively weak integration capacity. To solve this problem, we have searched for a way of determining the minimum number of bits to code the filter while keeping good accuracy on the filtering output. In this article, we briefly review B-spline function definitions and present how we use B-spline interpolation for the Image Rotation problem. We then describe the way we calculate the probability density function of the output error in order to determine the filter data coding.

Stefan Both - One of the best experts on this subject based on the ideXlab platform.

  • should Image Rotation be addressed during routine cone beam ct quality assurance
    Physics in Medicine and Biology, 2013
    Co-Authors: A.s. Ayan, Caitlyn Yeager, Curtiland Deville, James Mcdonough, N. Anderson, Voichita Bar Ad, Hsiao-ming Lu, Stefan Both
    Abstract:

    The purpose of this study is to investigate whether quality assurance (QA) for cone-beam computed tomography (CBCT) Image Rotation is necessary in order to ensure the accuracy of CBCT based Image-guided radiation therapy (IGRT) and adaptive radiotherapy (ART). Misregistration of angular coordinates during CBCT acquisition may lead to a rotated reconstructed Image. If target localization is performed based on this Image, an under- or over-dosage of the target volume (TV) and organs at risk (OARs) may occur. Therefore, patient CT Image sets were rotated by 1° up to 3° and the treatment plans were recalculated to quantify changes in dose–volume histograms. A computer code in C++ was written to model the TV displacement and overlap area of an ellipse shape at the target and dose prescription levels corresponding to the Image Rotation. We investigated clinical scenarios in IGRT and ART in order to study the implications of Image Rotation on dose distributions for: (1) lateral TV and isocenter (SBRT), (2) central TV and isocenter (IMRT), (3) lateral TV and isocenter (IMRT). Mathematical analysis showed the dose coverage of TV depends on its shape, size, location, and orientation relative to the isocenter. Evaluation of three first scenario for θ = 1° showed variations in TV D95 in the context of IGRT and ART when compared to the original plan were within 2.7 ± 2.6% and 7.7 ± 6.9% respectively while variations in the second and third scenarios were less significant (<0.5%) for the angular range evaluated. However a larger degree of variation was found in terms of minimum and maximum doses for target and OARs. The Rotation of CBCT Image data sets may have significant dosimetric consequences in IGRT and ART. The TV's location relative to isocenter and shape determine the extent of alterations in dose indicators. Our findings suggest that a CBCT QA criterion of 1° would be a reasonable action level to ensure accurate dose delivery.

  • Should Image Rotation be addressed during routine cone-beam CT quality assurance?
    Physics in Medicine and Biology, 2013
    Co-Authors: A.s. Ayan, Caitlyn Yeager, Curtiland Deville, James Mcdonough, N. Anderson, Voichita Bar Ad, Hsiao-ming Lu, Stefan Both
    Abstract:

    The purpose of this study is to investigate whether quality assurance (QA) for cone-beam computed tomography (CBCT) Image Rotation is necessary in order to ensure the accuracy of CBCT based Image-guided radiation therapy (IGRT) and adaptive radiotherapy (ART). Misregistration of angular coordinates during CBCT acquisition may lead to a rotated reconstructed Image. If target localization is performed based on this Image, an under- or over-dosage of the target volume (TV) and organs at risk (OARs) may occur. Therefore, patient CT Image sets were rotated by 1° up to 3° and the treatment plans were recalculated to quantify changes in dose–volume histograms. A computer code in C++ was written to model the TV displacement and overlap area of an ellipse shape at the target and dose prescription levels corresponding to the Image Rotation. We investigated clinical scenarios in IGRT and ART in order to study the implications of Image Rotation on dose distributions for: (1) lateral TV and isocenter (SBRT), (2) central TV and isocenter (IMRT), (3) lateral TV and isocenter (IMRT). Mathematical analysis showed the dose coverage of TV depends on its shape, size, location, and orientation relative to the isocenter. Evaluation of three first scenario for θ = 1° showed variations in TV D95 in the context of IGRT and ART when compared to the original plan were within 2.7 ± 2.6% and 7.7 ± 6.9% respectively while variations in the second and third scenarios were less significant (

S. Suchitra - One of the best experts on this subject based on the ideXlab platform.

  • Techniques for area-time efficient Image Rotation
    2009 IEEE International Symposium on Circuits and Systems, 2009
    Co-Authors: R. K. Satzoda, S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation is a necessary task in many vision based applications. Most available Image Rotation architectures are serial in nature, while the existing parallel techniques suffer from computational bottlenecks, limiting their performance. In this paper, we propose techniques that not only speed up the Rotation process but also reduce area, yielding an area-time efficient architecture. They exploit properties of symmetry in Image coordinates for parallel Image Rotation. We show that the number of computations, the total computation time and area cost of the proposed architecture are lesser by as much as 80%, 55% and 67% respectively when compared to the most efficient parallel architecture in recent literature.

  • ISCAS - Techniques for area-time efficient Image Rotation
    2009 IEEE International Symposium on Circuits and Systems, 2009
    Co-Authors: R. K. Satzoda, S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation is a necessary task in many vision based applications. Most available Image Rotation architectures are serial in nature, while the existing parallel techniques suffer from computational bottlenecks, limiting their performance. In this paper, we propose techniques that not only speed up the Rotation process but also reduce area, yielding an area-time efficient architecture. They exploit properties of symmetry in Image coordinates for parallel Image Rotation. We show that the number of computations, the total computation time and area cost of the proposed architecture are lesser by as much as 80%, 55% and 67% respectively when compared to the most efficient parallel architecture in recent literature.

  • ICIP - High-throughput Image Rotation using sign-prediction based redundant CORDIC algorithm
    2004 International Conference on Image Processing 2004. ICIP '04., 2004
    Co-Authors: S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation forms a core operation in many applications such as medical Image processing and computer vision. High-throughput computations for Image Rotation are a common requirement in real-time Image processing. A VLSI design for Image Rotation that employs CORDIC was discussed in Ghosh et al. (1994). In this paper, we propose novel techniques to increase the throughput of the CORDIC computations, thereby notably improving the overall performance of the Rotation unit with acceptable increase in VLSI area. An efficient sign-prediction method called BTSP (Binary-Tree based Sign Prediction) is proposed in our redundant CORDIC system to eliminate the sign detection process. Our investigations show that the BTSP based CORDIC algorithm for realtime Rotation of a 512/spl times/512-pixel Image, has a significant speed-up over existing redundant CORDIC methods with reduced hardware area.

  • Novel schemes for high-throughput Image Rotation
    Conference Record of the Thirty-Eighth Asilomar Conference on Signals Systems and Computers 2004., 2004
    Co-Authors: S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation forms a core operation in many applications such as medical Image processing, computer graphics and pattern recognition. Conventional Rotation engines usually comprise of compute-intensive CORDIC operations that become a severe bottleneck in high-throughput applications. In this paper, we present a novel scheme that employs hierarchical computation strategies, exploits the symmetrical characteristics of the Image, and performs successive pixel computations at high-speed to achieve high-throughput Image Rotation at low cost. We show that the proposed method leads to a significant performance gain of about 20 times over an existing CORDIC-based Rotation engine with similar hardware cost.

  • High-throughput Image Rotation using sign-prediction based redundant CORDIC algorithm
    2004 International Conference on Image Processing 2004. ICIP '04., 2004
    Co-Authors: S. Suchitra, T. Srikanthan
    Abstract:

    Real-time Image Rotation forms a core operation in many applications such as medical Image processing and computer vision. High-throughput computations for Image Rotation are a common requirement in real-time Image processing. A VLSI design for Image Rotation that employs CORDIC was discussed in Ghosh et al. (1994). In this paper, we propose novel techniques to increase the throughput of the CORDIC computations, thereby notably improving the overall performance of the Rotation unit with acceptable increase in VLSI area. An efficient sign-prediction method called BTSP (Binary-Tree based Sign Prediction) is proposed in our redundant CORDIC system to eliminate the sign detection process. Our investigations show that the BTSP based CORDIC algorithm for realtime Rotation of a 512/spl times/512-pixel Image, has a significant speed-up over existing redundant CORDIC methods with reduced hardware area.

Voichita Bar Ad - One of the best experts on this subject based on the ideXlab platform.

  • should Image Rotation be addressed during routine cone beam ct quality assurance
    Physics in Medicine and Biology, 2013
    Co-Authors: A.s. Ayan, Caitlyn Yeager, Curtiland Deville, James Mcdonough, N. Anderson, Voichita Bar Ad, Hsiao-ming Lu, Stefan Both
    Abstract:

    The purpose of this study is to investigate whether quality assurance (QA) for cone-beam computed tomography (CBCT) Image Rotation is necessary in order to ensure the accuracy of CBCT based Image-guided radiation therapy (IGRT) and adaptive radiotherapy (ART). Misregistration of angular coordinates during CBCT acquisition may lead to a rotated reconstructed Image. If target localization is performed based on this Image, an under- or over-dosage of the target volume (TV) and organs at risk (OARs) may occur. Therefore, patient CT Image sets were rotated by 1° up to 3° and the treatment plans were recalculated to quantify changes in dose–volume histograms. A computer code in C++ was written to model the TV displacement and overlap area of an ellipse shape at the target and dose prescription levels corresponding to the Image Rotation. We investigated clinical scenarios in IGRT and ART in order to study the implications of Image Rotation on dose distributions for: (1) lateral TV and isocenter (SBRT), (2) central TV and isocenter (IMRT), (3) lateral TV and isocenter (IMRT). Mathematical analysis showed the dose coverage of TV depends on its shape, size, location, and orientation relative to the isocenter. Evaluation of three first scenario for θ = 1° showed variations in TV D95 in the context of IGRT and ART when compared to the original plan were within 2.7 ± 2.6% and 7.7 ± 6.9% respectively while variations in the second and third scenarios were less significant (<0.5%) for the angular range evaluated. However a larger degree of variation was found in terms of minimum and maximum doses for target and OARs. The Rotation of CBCT Image data sets may have significant dosimetric consequences in IGRT and ART. The TV's location relative to isocenter and shape determine the extent of alterations in dose indicators. Our findings suggest that a CBCT QA criterion of 1° would be a reasonable action level to ensure accurate dose delivery.

  • Should Image Rotation be addressed during routine cone-beam CT quality assurance?
    Physics in Medicine and Biology, 2013
    Co-Authors: A.s. Ayan, Caitlyn Yeager, Curtiland Deville, James Mcdonough, N. Anderson, Voichita Bar Ad, Hsiao-ming Lu, Stefan Both
    Abstract:

    The purpose of this study is to investigate whether quality assurance (QA) for cone-beam computed tomography (CBCT) Image Rotation is necessary in order to ensure the accuracy of CBCT based Image-guided radiation therapy (IGRT) and adaptive radiotherapy (ART). Misregistration of angular coordinates during CBCT acquisition may lead to a rotated reconstructed Image. If target localization is performed based on this Image, an under- or over-dosage of the target volume (TV) and organs at risk (OARs) may occur. Therefore, patient CT Image sets were rotated by 1° up to 3° and the treatment plans were recalculated to quantify changes in dose–volume histograms. A computer code in C++ was written to model the TV displacement and overlap area of an ellipse shape at the target and dose prescription levels corresponding to the Image Rotation. We investigated clinical scenarios in IGRT and ART in order to study the implications of Image Rotation on dose distributions for: (1) lateral TV and isocenter (SBRT), (2) central TV and isocenter (IMRT), (3) lateral TV and isocenter (IMRT). Mathematical analysis showed the dose coverage of TV depends on its shape, size, location, and orientation relative to the isocenter. Evaluation of three first scenario for θ = 1° showed variations in TV D95 in the context of IGRT and ART when compared to the original plan were within 2.7 ± 2.6% and 7.7 ± 6.9% respectively while variations in the second and third scenarios were less significant (