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Selected Area Optical Transforms in Real Time

IP.com Disclosure Number: IPCOM000060627D
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Krakow, W: AUTHOR

Abstract

Presently, two methods exist for obtaining the optical transform of an electron microscope image after the micrograph has been taken. In one of these methods, a transparency is placed in an optical diffractometer, while in a second method the electron microscope image is digitized in the frame store to obtain its Fourier transform. Both methods can use field stops when images are placed in the respective systems, but both methods are offline. That is, a photographic transparency or print must fir be produced, after which an aperture is placed over it to obtain a selected field of view. In order to overcome this difficulty, an online electronic aperture is used for forming optical transforms.

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Selected Area Optical Transforms in Real Time

Presently, two methods exist for obtaining the optical transform of an electron microscope image after the micrograph has been taken. In one of these methods, a transparency is placed in an optical diffractometer, while in a second method the electron microscope image is digitized in the frame store to obtain its Fourier transform. Both methods can use field stops when images are placed in the respective systems, but both methods are offline. That is, a photographic transparency or print must fir be produced, after which an aperture is placed over it to obtain a selected field of view. In order to overcome this difficulty, an online electronic aperture is used for forming optical transforms.

The electronic aperture is an aperture which is mathematically generated by the computer and displayed on the frame sto It is not a physical stop, but is an electronically generated construct to allow reduced areas of a digital image to be operated upon The computer program can write into a graphics ove on the digital frame store an outlined area from which the Fourier transform will be taken. The outlined area can be changed under computer control. In conjunction with the visible graphics, the dimensions of the graphics area are stored on the host computer controlling the frame store. When the image is shipped back to the host computer the image is modified by software so that only the area enclosed by the graphics produces an im...