Semi-automated penguin counting from digital aerial photographs

Semi-automated software has been written in Matlab to enable nesting Adelie penguins (Pygoscelis adeliae), on aerial photographs of the Ross Sea sector of Antarctica, to be counted. Previously, this task had been accomplished by manual marking of printed images; this is slow, and highly-dependent on the skill of the operator. The basis of the semi-automated counting procedure is to use linear discriminant analysis to separate the background (snow, water, rock, bare ground) from the guano-covered colony area, followed by morphological image processing operators to select the breeding penguins. Many interactive features are provided that allow an operator to delete penguins singly or in groups, selectively process a defined area, and record the running census counts.