A Method Based on Ellipse Fitting for Automatic Morphometric Parameter Measurements of Fish Blood Cells

Thanks to their sensitivity to different changes affecting the environment and capability of demonstrating the impacts of various pollutant types, fishes are considered valuable and suitable species to be used as bioindicators for the water body pollution. Measurement of Morphometric parameters of Fish Erythrocytes (MFE) has been considered a valuable approach for analysis of health status of fishes. Conventional MFE measurement methods have several limitations, including poor measurement reproducibility and reliability, since they rely mainly on the human expertise, as well as required intensive highly time-consuming work to take measurements manually. To address these issues, this work presents a solution based on image processing and ellipse fitting technique to automatically measure MFE. The proposed method first applies customized image processing steps to locate cells in the image, segments nucleus and border of cells, and then uses the ellipse fitting algorithm to fit ellipse on detected cell/nucleus. The effectiveness of the proposed method has been validated through the comparison of results carried out by two expert biologists. The experimental results show that the proposed method properly fit the ellipse on both fish blood cell and its nucleus, indicating its potential as a promising tool for biomonitoring applications.