Camera parameter optimisation for depth from defocus

CAMERA PARAMETER OPTIMISATION FOR DEPTH FROM DEFOCUS Abstract A method, apparatus and system of selecting a parameter step size are disclosed. The method selects a parameter step size for capturing at least two images of a scene using an image capture device, said method comprises determining, for at least one parameter step size and at least one depth, a plurality of depth sensitivity measurements (520) for the image capture device for each of a plurality of spatial frequencies from an optical transfer function associated with the image device, wherein a point spread function, associated with the optical transfer function at a given focus depth, has a non-zero radius. The method further comprises selecting a deterministic spectral scene function associated with the scene and determining depth accuracy (540) from the plurality of determined depth sensitivity measurements, said depth accuracy being determined by weighting the depth sensitivity measurements with the selected deterministic spectral scene function (530). The method further comprises selecting, based on the determined depth accuracy, the parameter step size (560) from at least one parameter step size for capturing the at least two images of the scene. QQIQ2"7Q I D12C0rfn -5/8 Start Set up camera aimed at scene Set focus, zoom, aperture |Select focus step size K 440 Capture first image of scene Change focus by focus step size Capture second image of scene K 470 Determine depth map Fig. 4 471_1