A system for supporting a depth estimation procedure, comprising: a capture subsystem for capturing images of a photographic target, said capture subsystem including an aperture that is adjustable for admitting reflected light from said photographic target to a sensor device; an adaptive kernel that is designed in a kernel design procedure based upon circular symmetry characteristics of said aperture, wherein camera aperture data including an aperture shape and aperture dimensions is obtained, said kernel design procedure further including analyzing said camera aperture data to determine said circular symmetry characteristics, symmetrical kernel coefficients being stored in a local memory device if said circular symmetry characteristics indicate that said aperture is circularly-symmetrical, and wherein asymmetrical kernel coefficients are designed in said kernel design procedure, said asymmetrical kernel coefficients being stored in said local memory device if said circular symmetry characteristics indicate that said aperture is circularly-asymmetrical; and a depth estimator that utilizes said adaptive kernel in a depth-from-defocus technique in which the adaptive kernel is a convolution kernel used to match the blur of two image regions to derive an indirect estimate of the depth, for performing said depth estimation procedure wherein said asymmetrical kernel coefficients are designed in a frequency-domain kernel design procedure, wherein said frequency-domain kernel design procedure includes applying a Fast Fourier Transform to a point spread function of said aperture, designing a horizontal filter and a vertical filter based upon a horizontal cutoff frequency and a vertical cutoff frequency of said Fast Fourier Transform, said horizontal filter and said vertical filter being then combined to generate a combined filter, an inverse Fast Fourier Transform being performed on said combined filter to produce said adaptive kernel. a capture subsystem for capturing images of a photographic target, said capture subsystem including an aperture that is adjustable for admitting reflected light from said photographic target to a sensor device; an adaptive kernel that is designed in a kernel design procedure based upon circular symmetry characteristics of said aperture, wherein camera aperture data including an aperture shape and aperture dimensions is obtained, said kernel design procedure further including analyzing said camera aperture data to determine said circular symmetry characteristics, symmetrical kernel coefficients being stored in a local memory device if said circular symmetry characteristics indicate that said aperture is circularly-symmetrical, and wherein asymmetrical kernel coefficients are designed in said kernel design procedure, said asymmetrical kernel coefficients being stored in said local memory device if said circular symmetry characteristics indicate that said aperture is circularly-asymmetrical; and a depth estimator that utilizes said adaptive kernel in a depth-from-defocus technique in which the adaptive kernel is a convolution kernel used to match the blur of two image regions to derive an indirect estimate of the depth, for performing said depth estimation procedure wherein said asymmetrical kernel coefficients are designed in a frequency-domain kernel design procedure, wherein said frequency-domain kernel design procedure includes applying a Fast Fourier Transform to a point spread function of said aperture, designing a horizontal filter and a vertical filter based upon a horizontal cutoff frequency and a vertical cutoff frequency of said Fast Fourier Transform, said horizontal filter and said vertical filter being then combined to generate a combined filter, an inverse Fast Fourier Transform being performed on said combined filter to produce said adaptive kernel.