1. An integrated computational imaging system for producing images having an extended depth of field comprising: a multifocal imaging subsystem for producing an intermediate image that is purposefully blurred; the multifocal imaging subsystem exhibiting spherical aberration as the dominant feature of the purposeful blur; a central obscuration that cooperates with the spherical aberration to reduce variance among blurring effects through a range of defocused positions; and a digital processing subsystem for deblurring the intermediate image produced by the multifocal imaging subsystem and for calculating a recovered image having an extended depth of field.