Three-dimensional imaging and recognition of microorganisms using computational holography

In this keynote address, we introduce three-dimensional (3D) sensing, visualization and recognition of microorganisms using microscopy-based single-exposure on-line (SEOL) digital holography. A coherent Mach-Zehnder interferometer records Fresnel diffraction field by a single on-line exposure to generate a microscopic digital hologram. Complex amplitude distribution is numerically reconstructed by the inverse Fresnel transform at arbitrary depth planes. After the reconstruction of volumetric complex images, 3D biological micro-objects are segmented and features are extracted by Gabor-based wavelets. The graph matching technique searches predefined 3D morphological shapes of reference biological microorganisms. Preliminary experimental results using sphacelaria alga and tribonema aequale alga are presented.