Chemical-morphological relationships of rainbow trout, Oncorhynchus mykiss, computed by machine vision

The chemical-morphological relationships in rainbow trout, Oncorhynchus mykiss, was assessed through photography in light room. The image data were transferred to a laptop and analyzed by MATLAB (Matrix Laboratory) version R2009a. The designated algorithm of 7 features, including length, height, area, perimeter, equivalent diameter, major and minor axis length were extracted from the images. Afterward, chemical compositions of the fish (including crude protein, crude fat, moisture content, pH value and leakage), were determined. Pearson's correlation coefficient was used to correlate visual and chemical properties. Factors were assayed with linear, logarithmic, exponential and power method. Results showed that pH, leakage, protein and fat had a good correlation with fish length, and moisture with fish perimeter, in Quadratic equation (R2= 0.993, 0.991, 0.991, 0.989 and 0.992, respectively). In conclusion, this methodology can be applied for automated chemical analysis and on-line monitoring in fish farms.