Comparative analysis of several digital methods to recognize diatoms

Resumo

In this paper, several methods are presented and compared in order to choose the best digital algorithm to recognize the diatoms species. A digital system of invariant correlation to position and rotation is constructed. Based in a binary ring mask an average signature filter for a selected image is produced in four different ways and compared with variance spectrum modified methodology using four different ways too. It is conclusive that the best methodology for this case is presented in the first method when the binary mask with a nonlinear filter is used without high frequencies enhanced in the variance spectrum of the input image using an average filter of 10 input rotated images. Moreover the confidence level for this case was 100%. The second best case was for the average filter f18, with the same confidence level, but where the difference in time is more than one minute. One of the advantages of these kinds of methodologies is that an entire process can be repeated in the same way without mistakes and the diatoms images are kept save in a hard disk of the computer, so everybody can see again the diatom information of some special localization of the ocean.