Paper Info
Title
Sharpening-Demosaicking Method Wilth A Total-Variation-Based Super-Resolution Technique
Abstract
Most digital color cameras use doubly refractive crystal devices as an optical low-pass filter. The filter reduces frequency components lower than the Nyquist frequency, and images are blurred. We previously presented a demosaicking method that simultaneously removes blurs caused by the optical low-pass filter. For the sharpening-demosaicking approach, the Bayer's RGB color filter array is not necessarily proper, and we studied another color-filter array. namely the WRB filter array, where the W-filtering means that all the visible light passes through it. Our prototypal sharpening-demosaicking method employed the iterative algorithm, and restored only spatial frequency components of color signals lower than the Nyquist frequency corresponding to the mosaicking pattern of the W filters. However, the same recovery problem is solved by a non-iterative method in the Discrete Fourier Transform domain. Moreover, our prototypal method often produced ringing artifacts near sharp color edges. To suppress those artifacts, we introduce the total-variation-based super-resolution into the sharpening-demosaicking approach. This super-resolution approach restores spatial frequency components higher than the Nyquist frequency from observed blurry spatial frequency components so that without producing ringing artifacts it can demosaic and sharpen images while preserving 1D image structures that intensity values are almost constant along the edge direction.
Year
DOI
Venue
2005
10.1117/12.585204
Digital Photography
Keywords
Field
DocType
demosaicking, de-blurring, total variation, super-resolution, optical low-pass filter, color filter
Bayer filter,Computer vision,Ringing artifacts,Anti-aliasing filter,Nyquist frequency,Optics,Demosaicing,Aliasing,Low-pass filter,Artificial intelligence,Mathematics,Filter design
Conference
Volume
ISSN
Citations 
5678
0277-786X
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Takahiro Saito110030.46
Takashi Komatsu211333.96