Correction of x-ray images
AssigneeThe United States of America as represented by the Secretary of Agriculture
InventorRonald P Haff
Life of this patent
Estimating the term…
Abstract
A technique to correct deficiencies in x-ray images of cylindrical or spherical objects that are a consequence of the geometry of the sample is disclosed, for both normal imaging of stationary objects with film or digital detectors and linescan imaging of moving objects. The methods described involve the use of attenuators specifically shaped to equalize the x-ray absorption across the sample, thus correcting the variation in pixel intensity caused by the varying thickness of the sample.
Claims14
An x ray inspection apparatus comprising:
- a) A means for conveying a cylindrical or spherical object to a radiation source,
- b) an encoder for monitoring the conveyance of the object,
- c) a radiation source adapted to direct radiation along a path toward said object,
- d) a means for detecting entry of the object into the x ray plane,
- e) an attenuator with the appropriate shape and x-ray absorption coefficient to equalize x-ray attenuation across said object,
- f) a means for detecting the attenuated x ray signal,
- g) a microcontroller for synchronization of the encoder data and positioning of the attenuator.
A method for correcting deficiencies in x-ray images of cylindrical or spherical objects comprising:
- a) Placing a sample on a conveyor for movement of the object to a radiation source,
- b) positioning an attenuator of the appropriate shape and x-ray absorption coefficient to equalize x-ray attenuation across a cylindrical or spherical object within the x ray path,
- b) irradiation of the object with a radiation source adapted to direct radiation along a path toward said object,
- c) detecting and processing said attenuated signal to form a 2 dimensional image.
Dependencies are inferred from the claim text.