An efficient depth map estimation technique using complex wavelets

A new focus measure system is proposed based on complex wavelet transform and quadrature pair of steerable filters. In shape from focus (SFF), noise, illumination variation and oriented features degrade the performance of focus measure operator. This paper introduces the use of complex wavelets due to shift-invariance and directionality of the transformation suitable for detecting various types of features which plays a pivotal role in depth estimation of a scene. A quadrature pair of steerable filters is employed to measure focus by calculating the local oriented energy of the detected features. Experimental examples are provided to illustrate the effectiveness of the approach and the results compare favorably to well-documented methods in literature.