System and method for shutter detection
Inventors
Yu, Songyang • Accomazzi, Vittorio • Geiger, Paul
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-8218879-B2
Publication Date
2012-07-10
Expiration Date
Abstract
A method for removing shutter areas in an image, in particular an x-ray image is provided. Edges are examined in a multi-resolution image pyramid and evaluated to determine potential shutter blade candidates defining the shutter areas. Heuristic rules and/or an automatic classifier such as a Neuronal Network, are applied to distinguish true shutter blades from false positives. The rule set and the classifier are based on a set of features extracted from the potential shutter blade candidates as well as predetermined knowledge of the expected placement of the shutter, human anatomy. Up to four shutter blades are expected to be detected and based on these blades, the bright areas in the image that occur due to the shutters are removed.
Core Innovation
The invention detects and removes unwanted information in a medical image generated using a shutter having a plurality of blades. The approach processes the medical image to obtain edge information and generates a list of at least one candidate edge where each candidate edge corresponds to a single blade of the shutter.
Candidate edges are selected from a lowest image level and promoted through subsequent image levels until a highest image level, and the promoted candidate edges at the highest level are used as the list of candidate edges. Each candidate edge is evaluated according to a predetermined rule set to select one or more candidate edges considered to define the extent of the unwanted information within the image.
The evaluating comprises comparing the candidate edge(s) to other information in the image. After selecting the candidate edge(s), unwanted information is removed based on the location of the selected candidate edge(s) in the image.
Claims Coverage
The independent claims are directed to a method and a system for detecting and removing unwanted information in a medical image. Each independent claim includes five inventive features covering edge-information processing, shutter-blade-linked candidate edge generation with multi-resolution promotion, rule-set based selection defining the extent of unwanted information, and removing unwanted information based on selected edge locations.
Multi-resolution edge-information processing with down sampling
Down sampling said image to generate a plurality of image levels having successively decreasing image resolutions and processing said image to obtain edge information.
Shutter-blade-corresponding candidate edge list via promotion across image levels
Generating a list of at least one candidate edge from said edge information according to predetermined criteria, wherein each of said at least one candidate edge corresponds to a single blade of a shutter, selecting a first candidate list at a lowest of said plurality of image levels, promoting said first candidate list through subsequent image levels until a highest of said image levels, and using candidate edges promoted to said highest of said image levels as said list of at least one candidate edge.
Predetermined rule set evaluation selecting edges defining unwanted-information extent
Evaluating each of said at least one candidate edge according to a predetermined rule set to select one or more of said at least one candidate edge considered to define the extent of said unwanted information within said image, wherein said evaluating comprises comparing said at least one candidate edge to other information in said image.
Removal of unwanted information based on locations of selected candidate edges
Removing said unwanted information based on the location of said one or more of said at least one candidate edge in said image.
System interface with display and image processing program for edge-based unwanted-information removal
An interface comprising a display for viewing said image and enabling a user to interact with said system, and an image processing program capable of obtaining and processing said image from a medical imaging device and displaying said image on said display, said image processing program configured to perform the processing for obtaining edge information, generating and promoting a candidate edge list tied to shutter blades, evaluating candidate edges with a predetermined rule set comparing to other image information, and removing unwanted information based on locations of selected candidate edges.
The claims cover a shutter-blade-based edge detection workflow in which edge information is obtained using down sampling to multiple resolution levels, candidate edges corresponding to shutter blades are generated and promoted to a highest image level, the candidate edges are evaluated by a predetermined rule set comparing to other image information to define the extent of unwanted information, and unwanted information is removed based on the locations of the selected candidate edges.
Stated Advantages
Detecting and removing unwanted information in a medical image generated using a shutter.
Defining the extent of unwanted information based on selected candidate edges corresponding to shutter blades.
Documented Applications
Detecting and removing unwanted information in medical (x-ray) images generated using a shutter, with the processed/cleaned image displayed.
Interested in licensing this patent?