4. Conclusions and Future Work

We presented a novel framework for analyzing and designing imaging systems for the class of grayscale objects where the different spectral bands have strong correlation. We demonstrated how such correlation information enables the system designer not only to relax strict requirements on optical aberrations, but also enables new imaging capabilities such as extended depth-of-field imaging through spectral coding. We used our new design philosophy to design an extended depth-of-field triplet imaging system verifying the increased depth-of-field through image simulation. Finally, we highlighted the additional advantage of this new approach to building simple object depth estimation using simple filter-based sharpness measures. The cost of such image processing is low enough to make this approach attractive for grayscale imaging systems.

The current work suggests numerous future research directions. In this report, we ignored the loss in spatial resolution due to spatial multiplexing of the color filters. The most practical application of the spectral coding will undoubtedly required such spatial multiplexing. Future research could address the processing required to restore resolution by combining the multiple color channel sub-images. In our work, we focussed on strongly correlated objects such as bar codes or grayscale documents. A general multispectral analysis of general images could reveal spectral correlations, albeit weaker, in general images. Future work might address methods for leveraging this weak spectral correlation information when designing general purpose imaging systems to improve F# and increase depth-of-field.

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