IMPROVED DATA PROCESSING METHOD AND APPARATUS

摘要

PCT No. PCT/GB96/01492 Sec. 371 Date Mar. 23, 1998 Sec. 102(e) Date Mar. 23, 1998 PCT Filed Jun. 19, 1996 PCT Pub. No. WO97/01152 PCT Pub. Date Jan. 9, 1997In a data processing method and apparatus, an image signal representative of features in a space of two or more dimensions is progressively filtered at monotonically increasing filtering scales, the signal being input to the first filtering scale, and the input to the or each subsequent filtering scale is the output signal from the previous scale. Each input has a number of data samples each of which represents a respective region of the space, and at each filtering scale those samples are sorted into connected-sets, each of which contains a plurality of substantially equal value to data samples or a respective individual data sample not in other sets. The process then selects those connected-sets which contain data samples having values which are local maxima or local minima and which represent a composite region of a size related in a predetermined way to the current filtering scale. Each selected set is then effectively merged with the adjacent connected-set which contains data samples of a value closest to that of the sample(s) in the selected connected-set. This is achieved by changing the latter's value to that of the samples in the adjacent connected set. The output signal for the filtering method is derived from the output of at least one of the filtering scales. In at least one of those scales, both connected-sets having local maxima and connected-sets having local minima are selected, thereby increasing the tolerance of the method to noise.