Abstract
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.