An improved image processing chain for mobile terminals
Master thesis
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http://hdl.handle.net/11250/137300Utgivelsesdato
2002Metadata
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Sammendrag
Based on the proposal in the report by Tryggve Mikkelsen [Mikkelsen, 2001] this thesis
investigates and discusses the implementation of a simplified image processing chain for
modern mobile terminals. Previous work on image processing in this field of application
has shown that the demosaicing operation, color space conversion and downsampling are
resource demanding pre-processing operations. The simplification potential of the signal
chain lies within the pictured scenario of using Bayer RGB from the image sensor directly
as input to the compression scheme. By omitting these pre-processing operations,
unnecessary use of limited resources of a mobile terminal is prevented, making it capable
of reducing the computational costs.
The work has shown that the simplified image processing chain can be implemented two
different ways. Either by using Bayer RGB as it appears from the image sensor as input
to the compression scheme or by using composite Bayer RGB where the colors red, green
and blue are distinguished into three arrays.
Both implementations reveal overall better results for SNR compared to classical JPEG
when lossless compression is applied. Furthermore, both implementations are capable of
better color reproduction than JPEG. Comparing the two implementations, however,
Bayer RGB appears to be capable of the best overall performance. In fact, taken into
account the expected computational savings of the simplified image processing chain,
conventional JPEG falls short on most evaluation criteria in this work compared to Bayer
RGB.
Beskrivelse
Masteroppgave i informasjons- og kommunikasjonsteknologi 2002 - Høgskolen i Agder, Grimstad
Utgiver
Høgskolen i AgderAgder University College