Identification of pelagic eggs by image analysis

Abstract

A pelagic egg identification system by image analysis is proposed. The egg image is obtained using a camera coupled with a microscope. In order to extract the meaningful structures of egg, the edge map of the egg image is used. Our edge detection method consists of two steps: 1. Mark on four edge maps the potential edge positions corresponding to the local maxima of gradients in four directions; 2. Identify the true edge positions in accordance with the local facet orientation and aggregate them into an edge map with some spatial pattern of regularity. Since most of these structures (except the embryo) have circular shapes, a circle detection method using the Hough transform is proposed, where the problem of circle over-detection in a possible site is resolved. An embryo segmentation method is also developed. Based on some criteria of identification defined on the parameters extracted from the structures detected, the pelagic eggs are then classified into the corresponding categories and the corresponding stages of development. Experimental results are also presented in the paper.