Phase estimation from transmitted-light DIC images using rotational diversity
Differential-Interference-Contrast (DIC) microscopy is a powerful technique for the visualization of unstained transparent specimens, thereby allowing in vivo observations. Quantitative interpretation of DIC images is difficult because the measured intensity is nonlinearly related to the gradient of a specimen's optical-path-length distribution along the shear direction. The recent development of reconstruction methods for DIC microscopy permits the calculation of a specimen's optical-path-length distribution or phase function and provides a new measurement technique for biological applications. In this paper we present a summary of our work on quantitative imaging with a DIC microscope. The focus of our efforts has been in two areas: 1, model development and testing for 3D DIC imaging; and 2, development of a phase-estimation method based on this model. Our method estimates a specimen's phase function using rotational-diversity DIC images, i.e. multiple DIC images obtained by rotating the specimen. Test objects were viewed with a conventional DIC microscope using monochromatic light, and images were recorded using a cooled CCD camera. Comparison of the images to model predictions show good qualitative and quantitative agreement. Results obtained from testing the phase-estimation method with 2D simulations and with measured DIC images demonstrate that an estimate of an object's phase function can be obtained even from a single DIC image and that the estimated phase becomes quantitatively better as the number of rotational-diversity DIC images increases.
Proceedings of SPIE - The International Society for Optical Engineering
Preza, C., Snyder, D., Rosenberger, F., Markham, J., & Conchello, J. (1997). Phase estimation from transmitted-light DIC images using rotational diversity. Proceedings of SPIE - The International Society for Optical Engineering, 97-107. https://doi.org/10.1117/12.292819