Interpolation of RGB components in Bayer CFA images CEG4311 Eric Dubois
Jan 08, 2016
Interpolation of RGB components in Bayer CFA images
CEG4311Eric Dubois
Demosaicking of Bayer-sampled color images
Problem: Most digital color cameras, capture only one color component at each spatial location. The remaining components must be reconstructed by interpolation from the captured samples. Objective: Develop algorithms to interpolate each color plane (called demosaicking) with best quality reconstruction, and with minimal computational complexity.
Construction of color image from color planes
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Lighthouseoriginal
Lighthousered original
Lighthousegreen original
Lighthouseblue original
Formation of Color planes
Lighthousered subsampled
Lighthousegreen subsampled
Lighthouseblue subsampled
LighthouseBayer CFA image
Color plane interpolation
GA
GB
GL GR
)(4
1ABRLI GGGGG
GI
Green channel: bilinear interpolation
Color plane interpolation
)(4
1SESWNENWC RRRRR
RC
Red channel: bilinear interpolation
RNW RNE
RSW RSE RS
SESWS RRR 2
1
Lighthousered interpolated
Lighthousegreen interpolated
Lighthouseblue interpolated
LighthouseInterpolated color image
Lighthouseoriginal
Can we do better?
Color planes have severe aliasing. Better interpolation of the individual planes has little effect.
Lighthousered interpolatedwith bilinear interpolator
Lighthousered interpolatedwith bicubic interpolator
Can we do better?
Color planes have severe aliasing. Better interpolation of the individual planes has little effect.
We could optically prefilter the image (blur it) so that aliasing is less severe.
Lighthousered interpolatedwith bilinear interpolator
Lighthouseprefiltered red interpolatedwith bilinear interpolator
LighthouseInterpolated color image
LighthousePrefiltered Interpolated color image
Lighthouseoriginal
LighthouseInterpolated color image with new frequency domain method