Subpixel Rendering of Bayer-Patterned Images

A common workflow in digital photography involves viewing high resolution images on LCD displays either computer monitors or camera viewfinders. To minimise cost and complexity, most cameras use a single sensor overlaid with a Bayer filter to selectively sample various wavelengths at interleaved locations. Missing data must then be interpolated, which is known to introduce artefacts. In order to show the image on a display with a lower resolution, it must then be downsampled, which introduces more artefacts. This process usually does not take into account the fact that LCD displays are composed of horizontally displaced subpixels, which can be individually addressed to achieve a higher effective horizontal resolution. A new downsampling algorithm is proposed, which works directly within the Bayer domain and exploits subpixel resolution to produce images of higher detail than the naı̈ve demosaicking and downsampling combination.