Abstract
Filamentous fungi have often been characterized, classified or
identified with a major emphasis on macromorphological characters,
i.e. the size, texture and color of fungal colonies grown on one
or more identification media. This approach has been rejcted by
several taxonomists because of the subjectivity in the visual
evaluation and quantification (if any)of such characters and the
apparent large variability of the features. We present an image
analysis approach for objective identification and classification
of fungi. The approach is exemplified by several isolates of nine
different species of the genus Penicillium, known to be very
difficult to identify correctly. The fungi were incubated on YES
and CYA for one week at 25 C (3 point inoculation) in 9 cm Petri
dishes. The cultures are placed under a camera where a digital
image of the front of the colonies is acquired under optimal
illumination conditions and with an accurately calibrated
acquisition system. A PC-based system has been developed. After
acquisition and image correction it automatically determines the
size and position of the colonies in the digitized image. Having
localized the colonies it is possible to extract a number of
different features to distinguish between different species. The
results are surprisingly impressive. Classification of 151
colonies from the YES media and 194 colonies from the CYA media
was done using a quadratic classifier based on a normal
distribution. In both cases the result was 99% correctly
classified colonies. The key to this success is the factor of
objectiveness obtained through the application and selection of
species specific features that are embedded in the color, texture
and size of the colonies. Automatic identification of fungi could
be a future perspective, but more criteria or media should
probably be included if a larger number of species need to be
identified.
Original language | English |
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Title of host publication | Abstract book |
Place of Publication | Sydney |
Publication date | 1999 |
Pages | 267-268 |
Publication status | Published - 1999 |
Event | 9th International Congress of Bacteriology & Applied Microbiology, and 9th International Congress of Mycology - Sydney, Australia Duration: 16 Aug 1999 → 20 Aug 1999 |
Conference
Conference | 9th International Congress of Bacteriology & Applied Microbiology, and 9th International Congress of Mycology |
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Country/Territory | Australia |
City | Sydney |
Period | 16/08/1999 → 20/08/1999 |