Extended depth of field by colored apodization.

We describe an approach to achieving extended depth of field for a camera system based on reducing the aperture of the blue channel of a three-color camera by apodizing the lens with a yellow-colored filter. The resulting improvement in depth of field for the blue channel allows red and green channels to be digitally postprocessed for improved sharpness. Simulation confirms that our approach renders the modular transfer function of the system less dependent on object depth. Experimental test images verify the improvement in depth of field.