Camera functionality in modern mobile terminals : software FIR filter for demosaicing with RISC
Master thesis
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http://hdl.handle.net/11250/137416Utgivelsesdato
2001Metadata
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Sammendrag
This thesis discusses implementation and optimizing of the image pre-processing
operation demosaicing on a typical hardware architecture for mobile terminals. Work
has shown that the demosaicing operation is equivalent to the mathematical operation
of interpolation, and that optimizing potential lies within the implementation of the
anti-imaging filter for the interpolator. This filter can be realized as an FIR filter with
the filter coefficients obtained from a suitable interpolation function (kernel).
Through literature review, nearest neighbor replication, bilinear and cubic
convolution kernels were implemented and optimized according to a typical hardware
architecture found in mobile terminals. Typical hardware architecture used consisted
of ARM710T RISC processor with 8 KB on-chip cache and external SDRAM memory.
The work has shown that the cubic convolution interpolation kernel offers the best
image quality requiring only moderate computational effort. Though, dependent the
application area, and taking the whole camera system into consideration, bilinear
interpolation might be better suited as interpolation kernel for the demosaicing
operation in the mobile terminal. The bilinear interpolation offers a good trade-off
between the visual result and computational effort. The nearest neighbor replication
interpolation kernel offers the poorest image quality, but is the most computational
efficient of the kernels.
Beskrivelse
Masteroppgave i informasjons- og kommunikasjonsteknologi 2001 - Høgskolen i Agder, Grimstad
Utgiver
Høgskolen i AgderAgder University College