Adaptive Coded Aperture Photography

We show how the intrinsically performed JPEG compression of many digital still cameras leaves margin for deriving and applying image-adapted coded apertures that support retention of the most important frequencies after compression. These coded apertures, together with subsequently applied image processing, enable a higher light throughput than corresponding circular apertures, while preserving adjusted focus, depth of field, and bokeh. Higher light throughput leads to proportionally higher signal-to-noise ratios and reduced compression noise, or – alternatively– to lower shutter times. We explain how adaptive coded apertures can be computed quickly, how they can be applied in lenses by using binary spatial light modulators, and how a resulting coded bokeh can be transformed into a common radial one. Fig. 1. Camera prototype. A programmable liquid crystal array is integrated at the aperture plane of a consumer compound lens. A mask pattern of 7 × 7 binary bits is addressed by a microcontroller.