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Evaluation of tone mapping techniques for high dynamic range imaging

Hägg, Hanna LU (2012) In Master's Theses in Mathematical Sciences FMA820 20112
Mathematics (Faculty of Technology) and Numerical Analysis
Abstract
The aim of realistic graphics is the creation of images that provide the same visual responses that a viewer would experience in a real world scene.

There are different rendering techniques that produce high dynamic range images that capture the full intensity range of a scene. These images cannot be reproduced on a standard display due to limitations in device hardware. Therefore, a high dynamic range image requires mapping in order to be perceived as the real world scene on low dynamic range displays. This process is called tone mapping. This mapping is classified into global and local tone mapping operators, depending on the transformation they apply.

The aim of this thesis is to find a tone mapping algorithm that is fast enough... (More)
The aim of realistic graphics is the creation of images that provide the same visual responses that a viewer would experience in a real world scene.

There are different rendering techniques that produce high dynamic range images that capture the full intensity range of a scene. These images cannot be reproduced on a standard display due to limitations in device hardware. Therefore, a high dynamic range image requires mapping in order to be perceived as the real world scene on low dynamic range displays. This process is called tone mapping. This mapping is classified into global and local tone mapping operators, depending on the transformation they apply.

The aim of this thesis is to find a tone mapping algorithm that is fast enough to be used in mobile devices. The algorithm should also provide a visual response of an image that corresponds to the response of the real world scene.

This has been done by studying the theory behind the human visual system's responses to light and by examining four global and three local variants of tone mapping operators. These operators have been implemented in MATLAB and C. The results have then been analyzed considering computational time, error, and visual response.

The best images are obtained with a local tone mapping operator that is based on a bilateral filter. This is because it produces an image with local contrasts preserved. The bilateral filter requires long computational time but it is shown that it can be approximated by using a bilateral grid combined with a subsampling of the grid. The approximation yields equivalent results compared to the unaltered bilateral filter. The local operator based on the bilateral grid and subsampling is almost as fast as a global if the parameters are adequately optimized. (Less)
Please use this url to cite or link to this publication:
author
Hägg, Hanna LU
supervisor
organization
course
FMA820 20112
year
type
H2 - Master's Degree (Two Years)
subject
publication/series
Master's Theses in Mathematical Sciences
report number
LUTFMA-3230-2012
ISSN
1404-6342
language
English
id
2837429
date added to LUP
2012-09-20 15:04:53
date last changed
2012-09-20 15:04:53
@misc{2837429,
  abstract     = {The aim of realistic graphics is the creation of images that provide the same visual responses that a viewer would experience in a real world scene.

There are different rendering techniques that produce high dynamic range images that capture the full intensity range of a scene. These images cannot be reproduced on a standard display due to limitations in device hardware. Therefore, a high dynamic range image requires mapping in order to be perceived as the real world scene on low dynamic range displays. This process is called tone mapping. This mapping is classified into global and local tone mapping operators, depending on the transformation they apply. 

The aim of this thesis is to find a tone mapping algorithm that is fast enough to be used in mobile devices. The algorithm should also provide a visual response of an image that corresponds to the response of the real world scene. 

This has been done by studying the theory behind the human visual system's responses to light and by examining four global and three local variants of tone mapping operators. These operators have been implemented in MATLAB and C. The results have then been analyzed considering computational time, error, and visual response.

The best images are obtained with a local tone mapping operator that is based on a bilateral filter. This is because it produces an image with local contrasts preserved. The bilateral filter requires long computational time but it is shown that it can be approximated by using a bilateral grid combined with a subsampling of the grid. The approximation yields equivalent results compared to the unaltered bilateral filter. The local operator based on the bilateral grid and subsampling is almost as fast as a global if the parameters are adequately optimized.},
  author       = {Hägg, Hanna},
  issn         = {1404-6342},
  language     = {eng},
  note         = {Student Paper},
  series       = {Master's Theses in Mathematical Sciences},
  title        = {Evaluation of tone mapping techniques for high dynamic range imaging},
  year         = {2012},
}