Ross, S., Newton, R., Zhou, Y. M., Haffegee, J., Ho, M. W., Bolton, J. P. and Knight, D.
Quantitative image analysis of birefringent biological material.  Journal of Microscopy 187: 62-67 (1997).

A previously described optical technique for enhancing interference colour contrast in polarized light microscopy is adapted for quantitative image analysis. This is based on a linear relationship for colour intensity vs. molecular birefringence and degree of phase alignment, derived using nematic liquid crystal approximations, and verified experimentally. The image analysis is described and illustrated on a section of the marginal rib of the dogfish egg case.