A metric compilation analysis of terrestrial atmospheric turbulence suppression algorithms for use in long range digital video surveillance
- Authors: Walters, Bryn
- Date: 2012-08-14
- Subjects: Digital video. , Atmospheric turbulence , Electronic surveillance , Algorithms.
- Type: Thesis
- Identifier: uj:9246 , http://hdl.handle.net/10210/5693
- Description: M.Ing. , Atmospheric turbulence (also referred to as optical or heat Scintillation, or heat shimmer) is a particular problem encountered in video surveillance, especially over distances where the target object focused on is over lkm in the distance. Images obtained from video surveillance are commonly required to be of a high quality for object identification and classification. Atmospheric turbulence causes degradation in the image quality through the blurring and a warping of the image, making object identification difficult. Algorithms have and still are being developed to suppress the image turbulence in digital video footage and enhance detail. There is a lack of reliable comparisons among algorithms to provide research direction, methods for identification of the best algorithms for particular applications, identification of useful image processing techniques and a full understanding of the problem. This need and lack of comparisons among the algorithms and atmospheric turbulence degraded videos is identified through the problem identification chapter. A literature study is undertaken in which the source of atmospheric turbulence and models are identified, image processing techniques discussed, filtering of electromagnetic waves reviewed, a review of some equipment, and a discussion of metrics. This is followed by the presentation of a number of atmospheric turbulence suppression algorithms developed by other authors. After a discussion of the algorithm implementations, the experimental design is described for algorithm image quality and performance investigation as well as the effect of optical filters. Experimental results are presented and discussed which provide repeatable results pertaining to the algorithms' image quality and processing requirements. The results allowed identification of the algorithms' strengths and weaknesses, how they compare, and their suitability for real and post processing environments. Efficient performing software components were also able to be identified, particularly Illuminance-Reflectance adjustment. The experiments and results provide a solution to this atmospheric turbulence comparison problem.
- Full Text:
- Authors: Walters, Bryn
- Date: 2012-08-14
- Subjects: Digital video. , Atmospheric turbulence , Electronic surveillance , Algorithms.
- Type: Thesis
- Identifier: uj:9246 , http://hdl.handle.net/10210/5693
- Description: M.Ing. , Atmospheric turbulence (also referred to as optical or heat Scintillation, or heat shimmer) is a particular problem encountered in video surveillance, especially over distances where the target object focused on is over lkm in the distance. Images obtained from video surveillance are commonly required to be of a high quality for object identification and classification. Atmospheric turbulence causes degradation in the image quality through the blurring and a warping of the image, making object identification difficult. Algorithms have and still are being developed to suppress the image turbulence in digital video footage and enhance detail. There is a lack of reliable comparisons among algorithms to provide research direction, methods for identification of the best algorithms for particular applications, identification of useful image processing techniques and a full understanding of the problem. This need and lack of comparisons among the algorithms and atmospheric turbulence degraded videos is identified through the problem identification chapter. A literature study is undertaken in which the source of atmospheric turbulence and models are identified, image processing techniques discussed, filtering of electromagnetic waves reviewed, a review of some equipment, and a discussion of metrics. This is followed by the presentation of a number of atmospheric turbulence suppression algorithms developed by other authors. After a discussion of the algorithm implementations, the experimental design is described for algorithm image quality and performance investigation as well as the effect of optical filters. Experimental results are presented and discussed which provide repeatable results pertaining to the algorithms' image quality and processing requirements. The results allowed identification of the algorithms' strengths and weaknesses, how they compare, and their suitability for real and post processing environments. Efficient performing software components were also able to be identified, particularly Illuminance-Reflectance adjustment. The experiments and results provide a solution to this atmospheric turbulence comparison problem.
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Foreground segmentation in atmospheric turbulence degraded video sequences to aid in background stabilization
- Robinson, Philip E., Nel, Andre L.
- Authors: Robinson, Philip E. , Nel, Andre L.
- Date: 2016
- Subjects: Atmospheric turbulence , Video stabilization , Background subtraction
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/217644 , uj:21665 , Citation: Robinson, P.E. & Nel, A.L. 2016. Foreground segmentation in atmospheric turbulence degraded video sequences to aid in background stabilization.
- Description: Abstract: Video sequences captured over a long range through the turbulent atmosphere contain some degree of atmospheric turbulence degradation (ATD). Stabilization of the geometric distortions present in video sequences containing ATD and containing objects undergoing real motion is a challenging task. This is due to the difficulty of discriminating what visible motion is real motion and what is caused by ATD warping. Due to this, most stabilization techniques applied to ATD sequences distort real motion in the sequence. In this study we propose a new method to classify foreground regions in ATD video sequences. This classification is used to stabilize the background of the scene while preserving objects undergoing real motion by compositing them back into the sequence. A hand annotated dataset of three ATD sequences is produced with which the performance of this approach can be quantitatively measured and compared against the current state-of-the-art.
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- Authors: Robinson, Philip E. , Nel, Andre L.
- Date: 2016
- Subjects: Atmospheric turbulence , Video stabilization , Background subtraction
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/217644 , uj:21665 , Citation: Robinson, P.E. & Nel, A.L. 2016. Foreground segmentation in atmospheric turbulence degraded video sequences to aid in background stabilization.
- Description: Abstract: Video sequences captured over a long range through the turbulent atmosphere contain some degree of atmospheric turbulence degradation (ATD). Stabilization of the geometric distortions present in video sequences containing ATD and containing objects undergoing real motion is a challenging task. This is due to the difficulty of discriminating what visible motion is real motion and what is caused by ATD warping. Due to this, most stabilization techniques applied to ATD sequences distort real motion in the sequence. In this study we propose a new method to classify foreground regions in ATD video sequences. This classification is used to stabilize the background of the scene while preserving objects undergoing real motion by compositing them back into the sequence. A hand annotated dataset of three ATD sequences is produced with which the performance of this approach can be quantitatively measured and compared against the current state-of-the-art.
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Sharpening and contrast enhancement of atmospheric turbulence degraded video sequences
- Robinson, Philip, Walters, Bryn, Clarke, Willem
- Authors: Robinson, Philip , Walters, Bryn , Clarke, Willem
- Date: 2010
- Subjects: Atmospheric turbulence , Heat shimmer , Scinitillation , Terrestrial , Blind deconvolution , Illuminance , Reflectance
- Language: English
- Type: Abstract: Long range imaging systems that capture video through the atmosphere face a major problem in the form of atmospheric turbulence. This turbulence causes a phenomenon called heat shimmer which appears as a blurring and a wavering geometric distortion of the target scene which limits the effective range of the imaging system. We explore an image processing approach to mitigating the blurring effect of this distortion by using a blind deconvolution technique to sharpen the video signal and a dynamic illuminance-reflectance correction technique to improve the signal’s contrast. The algorithm is implemented on a Graphics Processing Unit to achieve near real-time performance. , Conference proceedings
- Identifier: http://hdl.handle.net/10210/16817 , uj:15811 , Robinson, P.E. & Clarke, W.A. Sharpening and Contrast enhancement of atmospheric turbulence degraded video sequences. Proceedings of the Twenty-First Annual Symposium of the Pattern Recognition Association of South Africa, November 2010, pp 247-252.
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- Authors: Robinson, Philip , Walters, Bryn , Clarke, Willem
- Date: 2010
- Subjects: Atmospheric turbulence , Heat shimmer , Scinitillation , Terrestrial , Blind deconvolution , Illuminance , Reflectance
- Language: English
- Type: Abstract: Long range imaging systems that capture video through the atmosphere face a major problem in the form of atmospheric turbulence. This turbulence causes a phenomenon called heat shimmer which appears as a blurring and a wavering geometric distortion of the target scene which limits the effective range of the imaging system. We explore an image processing approach to mitigating the blurring effect of this distortion by using a blind deconvolution technique to sharpen the video signal and a dynamic illuminance-reflectance correction technique to improve the signal’s contrast. The algorithm is implemented on a Graphics Processing Unit to achieve near real-time performance. , Conference proceedings
- Identifier: http://hdl.handle.net/10210/16817 , uj:15811 , Robinson, P.E. & Clarke, W.A. Sharpening and Contrast enhancement of atmospheric turbulence degraded video sequences. Proceedings of the Twenty-First Annual Symposium of the Pattern Recognition Association of South Africa, November 2010, pp 247-252.
- Full Text:
Mitigation of atmospheric turbulence distortions in long range video surveillance
- Robinson, P. E., Clarke, W. A.
- Authors: Robinson, P. E. , Clarke, W. A.
- Date: 2011
- Subjects: Atmospheric turbulence , Scintillation , Heat shimmer , Graphics processing units , Optical flow , Deblurring , Quality metrics
- Type: Article
- Identifier: http://hdl.handle.net/10210/16412 , uj:15771 , Citation: Robinson, P.E. & Clarke, W.A. 2011. Mitigation of atmospheric turbulence distortions in long range video surveillance, SAIEE Africa Research Journal, 102(1) March:16-28.
- Description: Abstract: This paper explores the problem of atmospheric turbulence in long range video surveillance. This turbulence causes a phenomenon called heat scintillation or heat shimmer which introduces distortions into the video being captured. The nature of these distortions is discussed and a number of possible solutions explored.
- Full Text:
- Authors: Robinson, P. E. , Clarke, W. A.
- Date: 2011
- Subjects: Atmospheric turbulence , Scintillation , Heat shimmer , Graphics processing units , Optical flow , Deblurring , Quality metrics
- Type: Article
- Identifier: http://hdl.handle.net/10210/16412 , uj:15771 , Citation: Robinson, P.E. & Clarke, W.A. 2011. Mitigation of atmospheric turbulence distortions in long range video surveillance, SAIEE Africa Research Journal, 102(1) March:16-28.
- Description: Abstract: This paper explores the problem of atmospheric turbulence in long range video surveillance. This turbulence causes a phenomenon called heat scintillation or heat shimmer which introduces distortions into the video being captured. The nature of these distortions is discussed and a number of possible solutions explored.
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