I am currently working with Distinguished Professor Gabor Herman in Discrete Imaging and Graphics Group. My general research interest are in image reconstrction from projections and its applications in biomedical imaging. More specifically, I am working on reconstructions in electron microscopy. We are interested in developing reconstruction methods that take into account and correct for the distance-dependent blurring that occurs during imaging process of a molecule by electron microscope.

In December 1959, Richard Feynman said in his famous speach "There’s Plenty of Room at the Bottom":

"The electron microscope is not quite good enough, with the greatest care and effort, it can only resolve about 10 angstroms. I would like to try and impress upon you while I am talking about all of these things on a small scale, the importance of improving the electron microscope by a hundred times. It is not impossible; it is not against the laws of diffraction of the electron. The wave length of the electron in such a microscope is only 1/20 of an angstrom. So it should be possible to see the individual atoms. What good would it be to see individual atoms distinctly? ..."

Today the resolution of some electron microscopes reached 0.5 of an Angstrom. As the technology of electron microscopy improves and the need for imaging larger specimens emerges, an imperfection of electron microscopes that has not been considered important is likely to become an essential limitation. This imperfection is due to the fact that the way electron microscopy blurs the object to be imaged is not uniform, but changes with the distance of a specimen layer from the electron source. Variation in blurring that occurs within a single specimen can be ignored when the imaged structures are of a small size and when the desired resolution in the reconstructed structure is not high. Recent advances in electron microscopy technology provide us with the potential of achieving atomic resolution, but reconstruction algorithms developed under the assumption of uniform blurring throughout the entire structure applied to real electron microscopic data will fail to achieve this (except possibly in the case of smaller molecules). This limitation can be removed if the images obtained by electron microscopes are corrected for the variable blurring before the reconstruction process, or if such correction takes place during the reconstruction process.

Read more about 3D electron tomography reconstructions and some of its applications:

Discrete Imaging and Graphics Group (DIG)     The Graduate Center, CS Department     Hunter College, CS Department

    Last revised: Jul 30, 2010, 10:40:33     Joanna Klukowska