An Efficient Algorithm for Focus Measure Computation in Constant Time

作者：Minhas Rashid^*; Mohammed Abdul Adeel; Wu Q M Jonathan

来源：IEEE Transactions on Circuits and Systems for Video Technology, 2012, 22(1): 152-156.

DOI：10.1109/TCSVT.2011.2133930

• Depth map
• focus measure
• integral image
• shape from focus
• steerable filters

This letter presents an efficient algorithm for focus measure computation, in constant time, to estimate depth map using image sequences acquired at varying focus. Two major factors that complicate focus measure computation include neighborhood support and gradient detection for oriented intensity variations. We present a distinct focus measure based on steerable filters that is invariant to neighborhood size and accomplishes fast depth map estimation at a considerably faster speed compared to other well-documented methods. Steerable filters represent architecture to synthesize filters of arbitrary orientation using a linear combination of basis filters. Such synthesis is helpful to analytically determine the filter output as a function of orientation. Steerable filters remove inherent limitations of traditional gradient detection techniques which perform inadequately for oriented intensity variations and low textured regions.

• 出版日期2012-1