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US 8,913,813 B2Granted
Method of determining spatial response signature of detector in computed radiography
AssigneeAgfa Healthcare NV
InventorsMarc Cresens, Herman Van Goubergen
Life of this patent
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Abstract
Method and system for determining the spatial response signature of a x-ray detector comprising a photostimulable phosphor by generating a flat field image of the detector, generating a low-pass filtered version of the flat field image and background demodulating the flat field image by pixel-wise dividing it by means of corresponding pixel values in the low-pass filtered version.
Claims20
Method of determining the spatial response signature of a two dimensional x-ray detector comprising a photostimulable phosphor by
- generating a flat field image by homogeneously exposing said detector to radiation and scanning the homogeneously exposed detector and by digitizing the scanned image, generating a low-pass filtered version of said flat field image,
- demodulating said flat field image by means of corresponding pixel values in said low-pass filtered version characterized in that
- said signature is obtained by processing multiple flat field images generated for the same detector and
- said multiple flat field images are spatially registered by applying spatial warping whereby a reference flat field image for said spatial warping is selected such that the maximum angular difference between the pixel matrices obtained by scanning said reference flat field image and any other of said multiple flat field images, is minimal.
1 more element
A computed radiography system comprising:
- a digitizer that generates a flat field image by homogeneously exposing a detector to radiation and scanning the homogeneously exposed detector and digitizing the scanned image,
- an image processor that generates a low-pass filtered version of said flat field image and demodulating said flat field image by means of corresponding pixel values in said low-pass filtered version;
- a signature storage that stores signatures obtained by processing multiple flat field images generated for the same detector;
- and
- wherein multiple flat field images are spatially registered by applying spatial warping whereby a reference flat field image for said spatial warping is selected such that the maximum angular difference between the pixel matrices obtained by scanning said reference flat field image and any other of said multiple flat field images, is minimal.
2 more elements
Dependencies are inferred from the claim text.