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Improvements of demosaicking and compression for single sensor digital cameras Doutre, Colin Ray
Abstract
Most consumer digital cameras captured colour images using a single light sensor and a colour filter array (CFA). This results in a mosaic image being captured, where at each pixel location either a red, green, or blue sample is obtained. The two missing colours at each location must be interpolated from the surrounding samples in a process known as demosaicking. In most current digital cameras, demosaicking is carried out in RGB colour space and later the image or video is converted to YCbCr 4:2:0 format and compressed with standard methods. Most previous research on demosaicking and compression in digital cameras has addressed the issues separately. That is, current demosaicking methods ignore the fact that the data will later be compressed, and compression techniques ignore the fact that the data was captured with a CFA. In this thesis we proposed two methods for optimizing the demosaicking and compression processes in digital cameras. First we propose a fast demosaicking method that directly produces an image in YCbCr 4:2:0 format (the colour format most commonly used in compression). This reduces the computational complexity relative to the conventional approach of performing demosaicking in the RGB space and later converting to YCbCr 4:2:0 format. Second, we propose two methods for compressing video captured with a CFA prior to demosaicking being performed. This allows us to take advantage of the smaller input data size, since demosaicking expands the number of samples by a factor of three. Our first CFA video compression method uses standard H.264, while our second method uses a modified motion compensation scheme that further increases compression efficiency by exploiting the properties of CFA data.
Item Metadata
Title |
Improvements of demosaicking and compression for single sensor digital cameras
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2007
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Description |
Most consumer digital cameras captured colour images using a single light sensor and
a colour filter array (CFA). This results in a mosaic image being captured, where at each
pixel location either a red, green, or blue sample is obtained. The two missing colours at
each location must be interpolated from the surrounding samples in a process known as
demosaicking. In most current digital cameras, demosaicking is carried out in RGB
colour space and later the image or video is converted to YCbCr 4:2:0 format and
compressed with standard methods. Most previous research on demosaicking and
compression in digital cameras has addressed the issues separately. That is, current
demosaicking methods ignore the fact that the data will later be compressed, and
compression techniques ignore the fact that the data was captured with a CFA.
In this thesis we proposed two methods for optimizing the demosaicking and
compression processes in digital cameras. First we propose a fast demosaicking method
that directly produces an image in YCbCr 4:2:0 format (the colour format most
commonly used in compression). This reduces the computational complexity relative to
the conventional approach of performing demosaicking in the RGB space and later
converting to YCbCr 4:2:0 format. Second, we propose two methods for compressing
video captured with a CFA prior to demosaicking being performed. This allows us to
take advantage of the smaller input data size, since demosaicking expands the number of
samples by a factor of three. Our first CFA video compression method uses standard
H.264, while our second method uses a modified motion compensation scheme that
further increases compression efficiency by exploiting the properties of CFA data.
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Genre | |
Type | |
Language |
eng
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Date Available |
2011-03-15
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0101193
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.