Simultaneous Capturing of RGB and Additional Band Images Using Hybrid Color Filter Array

Proposed Algorithm Overview

Abstract

Extra band information in addition to the RGB, such as the near-infrared (NIR) and the ultra-violet, is valuable for many applications. In this paper, we propose a novel color filter array (CFA), which we call "hybrid CFA," and a demosaicking algorithm for the simultaneous capturing of the RGB and the additional band images. Our proposed hybrid CFA and demosaicking algorithm do not rely on any specific correlation between the RGB and the additional band. Therefore, the additional band can be arbitrarily decided by users. Experimental results demonstrate that our proposed demosaicking algorithm with the proposed hybrid CFA can provide the additional band image while keeping the RGB image almost the same quality as the image acquired by using the standard Bayer CFA.

References

Simultaneous Capturing of RGB and Additional Band Images Using Hybrid Color Filter Array
Daisuke Kiku, Yusuke Monno, Masayuki Tanaka and Masatoshi Okutomi
Proceedings of IS&T/SPIE Electronic Imaging (EI), Digital Photography X, Vol.9023, pp.90230V-1-9, February, 2014. [PDF]
*Note for correction: We noticed that some coeeficients in equations (2) and (3) are inccorectly described in the original paper. We corrected this error and apologize for any inconveniences this may have caused.

Datasets

Lu et al.[2] and Sadeghipoor et al.[3]
RGB and NIR image pairs

Results

Visual comparison of the RGB and NIR images of the book


RGB	Original	Bayer & GBTF[1]	Lu et al.[2]	Sadeghipoor et al.[3]	Proposed

NIR	Original	Bayer & GBTF[1]	Lu et al.[2]	Sadeghipoor et al.[3]	Proposed

Visual comparison of the RGB and NIR images of the roof


RGB	Original	Bayer & GBTF[1]	Lu et al.[2]	Sadeghipoor et al.[3]	Proposed

NIR	Original	Bayer & GBTF[1]	Lu et al.[2]	Sadeghipoor et al.[3]	Proposed

The average PSNR performance

Algorithms	R	G	B	NIR
Bayer & GBTF [1]	34.30	38.85	35.35	NA
Lu et al.[2]	32.77	34.05	32.80	35.02
Sadeghipoor et al.[3]	32.03	33.53	32.32	33.88
Naive	32.06	35.66	33.05	29.48
Proposed	33.34	38.43	35.15	30.10

Visual comparison of the real scene example


RGB	NIR


Original RGB	Bayer & GBTF [1] RGB	Proposed RGB


Original NIR	Bayer & GBTF[1] NIR	Proposed NIR

References

[1] Pekkucuksen, I. and Altunbasak, Y., "Gradient based threshold free color filter array interpolation," Proc. of IEEE Int. Conf. on Image Processing (ICIP), 137-140, (2010).
[2] Lu, Y. M., Fredembach, C., Vetterli, M., and Susstrunk, S., "Designing color filter arrays for the joint capture of visible and near-infrared images," Proc. of IEEE Int. Conf. on Image Processing (ICIP), 3797-3800, (2009).
[3] Sadeghipoor, Z., Lu, Y. M., and Susstrunk, S., "Correlation-based joint acquisition and demosaicing of visible and near-infrared images," Proc. of IEEE Int. Conf. on Image Processing (ICIP), 3226-3229, (2011).