1. A method, comprising: rendering an output image of a scene from a plurality of separate microimages of an image of the scene at a depth of focus that defines an angle of projection in an optical phase space, each microimage of the plurality of separate microimages corresponding to a microlens in a microlens array, distance between the microimages being a nonintegral pixel value, at least two microimages overlapping at least in part, the rendering comprising, for a point on an image plane of the output image: determining a line of projection through the microimages in optical phase space according to the point and the angle of projection determined from the depth of focus; for each microimage, applying a kernel centered at a position on the microimage intersected by the line of projection to accumulate, from pixels at each of the plurality of microimages covered by the kernel at the respective position, values for each color channel accumulated from the plurality of microimages and calculated separately, one color channel from another, according to the kernel; and computing a value for a pixel at the point in the output image from the values for the color channels that were accumulated and calculated separately.