6533b7ddfe1ef96bd1274ace

RESEARCH PRODUCT

Shift-and-scale-invariant pattern recognition using an elliptic coordinate-transformed phase-only filter

Javier GarciaCarlos FerreiraTomasz Szoplik

subject

Complex conjugateSpatial filterbusiness.industryMaterials Science (miscellaneous)Mathematical analysisCoordinate systemPhase (waves)Scale invarianceIndustrial and Manufacturing Engineeringsymbols.namesakeOpticsFourier transformFilter (video)symbolsElliptic filterBusiness and International ManagementbusinessMathematics

description

A shift-and-scale-invariant elliptic coordinate-transformed phase-only filter in proposed. The filter is built in three steps: the complex conjugate of a basic-size target spectrum is calculated, its phase-only part is taken, and then the elliptic coordinate transformation is made. In the extreme case the scale ratio of recognizable objects equals 1:1.5, permitting good recognition of object sizes S within the range 0.83/= S/= 1.25. Discrimination abilities and relative Horner efficiencies of a few versions of the filter are calculated.

https://doi.org/10.1364/ao.31.004823