PROCEDURE FOR GENERATING TEMPLATE MASKS FOR DETECTING VARIABLE SIGNALS

This paper is concerned with the use of template masks for locating ob jects and their features in digital images. In an ideal case suitable masks would take the form of spatial matched filters for the chosen ob ject or feature profile. However, in practical situations, not only wi ll noise be present but also the signals themselves may vary. This pap er analyses the situation and formulates a procedure for generating su itable masks in such cases. The overall filter can be construed as a s pecial type of spatial matched filter with integral noise-whitening. T he method is applied to edge, corner and hole detection, and tradeoff formulae are derived connecting accuracy, sensitivity and computationa l load, with number of masks as the single free parameter.