Abstract:

To recognise patterns, correlation and deconvolution techniques are frequently used. The deconvolution yields an identification signal with maximum discrimination and extreme sensibility for small fluctuations in intensity and shape. The phase only filter has the advantage of been more easy to implement in laboratory and it can yield a recognition signal even when object and filter are only slightly similar. The autocorrelation exhibits the latter behaviour to a greater extent (specially when simple objects are to be recognised). In some cases what is of interest is not the equality but the similarity of shapes, e.g., when objects which appear in a fragmented way are to be recognised. In the present article a method to adjust the degree of acceptable similarity between filter and object is proposed and the object is recognised by means of a simple change in a coefficient appearing in the numerical proccessing.