Patent ID: 8624183
Filing Date: 2014-01-07
Classification: G06T,H01J

Abstract:
1. Method for determining a reconstructed image using a particle-optical apparatus, the particle-optical apparatus comprising: a particle source for producing a beam of particles, an object plane on which an object to be imaged may be placed, a condenser system for illuminating the object plane with the beam of particles, a projection system for forming an image of the object plane by imaging particles transmitted through the object on an image plane, and a detector for detecting the image, the detector comprising a semiconductor sensor having an array of pixels for providing a plurality of pixel signals from respective pixels of the array in response to particles incident on the detector, the method comprising: receiving the plurality of pixel signals, and determining a reconstructed image using Viterbi Detection on the plurality of pixel signals, by: modelling possible states of a path corresponding to a plurality of possible configurations incident on the detector by determining a plurality of possible state transitions between the pixels, wherein the states are characterized by a run-length constraint that there should be at least two ‘0’s between two ‘1’s; determining the path of state transitions having the highest probability of producing the plurality of pixel signals, and determining from the path of state transitions having the highest probability of producing the plurality of pixel signals, the configuration of particles incident on the detector; and modifying an output of the Viterbi detection by adjusting the determined configuration of particles incident on the detector to define: the modified output to be zero particles for pixels having zero particles in the output of the Viterbi detection, and the modified output to be one particle for pixels having one or more particles in the output of the Viterbi detection.