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US 11,145,033 B2Granted
Method and device for image correction
AssigneeCarl Zeiss AG
InventorEberhard Derndinger
Life of this patent
Estimating the term…
Abstract
Methods, apparatuses and computer programs for image processing, in particular image correction, are provided. A sequence of images is processed in this case. Fluctuations, for example as a result of air schlieren, may be recognized and compensated for by identifying a fluctuation signature.
Claims11
A method of image processing by a computing device, the method comprising:
- calculating a spectral density of each recorded image in a temporal sequence of recorded images, each spectral density comprising a set of spectral density values corresponding to respective spatial frequencies and obtained by applying a frequency-domain transform to the recorded image;
- detecting a fluctuation in the spectral densities across respective ones of the recorded images;
- comparing the fluctuation to stored fluctuation signatures representing characterized disturbances affecting acquisition by an imager that produced the recorded images, each fluctuation signature comprising a set of complex values for each one or more of the respective spatial frequencies, with each complex value corresponding to a respective one of the recorded images;
- responsive to the fluctuation matching one of the stored fluctuation signatures, generating a modified set of spectral density values that is compensated for the characterized disturbance represented by the matched fluctuation signature, the modified set of spectral density values modified in dependence on the matched fluctuation signature;
- and
- generating a restored image, or at least a portion thereof, by transforming the modified set of spectral density values back into a space domain of the recorded images, to produce a corresponding set of space domain values comprising intensity values for respective pixel positions of the imager.
3 more elements
An apparatus for image processing, the apparatus comprising:
- a computing device having at least one processor and a memory, wherein a temporal sequence of recorded images is storable in the memory, and wherein the processor is configured to:
- calculate a spectral density of each recorded image in the temporal sequence of recorded images, each spectral density comprising a set of spectral density values corresponding to respective spatial frequencies and obtained by applying a frequency-domain transform to the recorded image;
- detect a fluctuation in the spectral densities across respective ones of the recorded images;
- compare the fluctuation to stored fluctuation signatures representing characterized disturbances affecting acquisition by an imager that produced the recorded images, each fluctuation signature comprising a set of complex values for each one or more of the respective spatial frequencies, with each complex value corresponding to a respective one of the recorded images;
- responsive to the fluctuation matching one of the stored fluctuation signatures, generate a modified set of spectral density values that is compensated for the characterized disturbance represented by the matched fluctuation signature, the modified set of spectral density values modified in dependence on the matched fluctuation signature;
- and
- generate a restored image, or at least a portion thereof, by transforming the modified set of spectral density values back into a space domain of the recorded images, to produce a corresponding set of space domain values comprising intensity values for respective pixel positions of the imager.
4 more elements
Dependencies are inferred from the claim text.