Median filtering in multispectral filter array demosaicking

Xingbo Wang (1, 2) , Jean-Baptiste Thomas (1) , Jon Yngve Hardeberg (2) , Pierre Gouton (1)

1 Le2i - Laboratoire Electronique, Informatique et Image [UMR6306]
2 Norwegian Colour and Visual Computing Laboratory

Inspired by the concept of the colour filter array (CFA), the research community has shown much interest in adapting the idea of CFA to the multispectral domain, producing multispectral filter array (MSFAs). In addition to newly devised methods of MSFA demosaicking, there exists a wide spectrum of methods developed for CFA. Among others, some vector based operations can be adapted naturally for multispectral purposes. In this paper, we focused on studying two vector based median filtering methods in the context of MSFA demosaicking. One solves demosaicking problems by means of vector median filters, and the other applies median filtering to the demosaicked image in spherical space as a subsequent refinement process to reduce artefacts introduced by demosaicking. To evaluate the performance of these measures, a tool kit was constructed with the capability of mosaicking, demosaicking and quality assessment. The experimental results demonstrated that the vector median filtering performed less well for natural images except black and white images, however the refinement step reduced the reproduction error numerically in most cases. This proved the feasibility of extending CFA demosaicking into MSFA domain.

Mots clés: demosaicking; multispectral; median filtering; n-sphere; colour filter array; spectral filter array

Domaines: Traitement des images [eess.IV]; Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Xingbo Wang, Jean-Baptiste Thomas, Jon Yngve Hardeberg, Pierre Gouton. Median filtering in multispectral filter array demosaicking. Digital Photography IX, Feb 2013, Burlingame, United States. Digital Photography IX, 86600E, ⟨10.1117/12.2005256⟩. ⟨hal-00847768⟩