05-01-2017 дата публикации
Номер: US20170004601A1
Принадлежит:
A method for reducing noise in flouroscopic images by detection of the traits in the curvelet domain, matching of the detected traits and time-domain filtering adapted to the type of coefficients associated with a trait. The method uses the discrete curvelet transforms of the images from a sequence. The denoised coefficients are detected, then transmitted to a step for locally matching the traits, the matched data subsequently undergo a step for time-domain filtering allowing the movement of the objects to be preserved in the image and a step for a 2D IDCT (Inverse Discrete Curvelet Transform) in order to produce the final image. 1. A method for reducing noise in a sequence of fluoroscopic images acquired by an X-ray detector , an image comprising one or more traits , an image being represented by curvelet coefficients c , where s is the scale of the image , θits sub-band linked to the angle of a trait in the image and (i ,j) its relative position , the method comprising in combination at least the following steps:{'sub': 'sb', 'detection of the traits in an image in the curvelet domain, using the curvelet coefficients sub-band by sub-band and by determining the maximum response of a filter associated with a sub-band θ, and the detected traits are stored in memory,'} considering a set of curvelet coefficients, testing whether a curvelet coefficient being considered belongs to a trait detected at the time t or at an earlier time,', 'if the curvelet coefficient belongs to a detected trait, testing whether the trait, to which the coefficient belongs, is matched to a trait detected at an earlier time, if this is the case, then the curvelet coefficient is categorized in a first set,', 'if the coefficient is not detected, or if the curvelet coefficient belongs to a trait detected but non matched to a trait detected at an earlier time, then forming at least a second set,', 'applying a first coefficient for time-domain filtering the curvelet coefficients belonging to the ...
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