Method and apparatus for three-dimensional object segmentation
AssigneeCognex Corporation
InventorSanjay Nichani
Life of this patent
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Abstract
A three-dimensional (3-D) machine-vision involving a method and apparatus for performing segmentation of 3-D objects. Multiple stereo-related sets (left/right, top/left, top/right) of two-dimensional video pixel data are separately processed into sets of edges. Each stereo-related set is then pair-wise processed to convert pairs of sets of edge data into 3-D point data. Multiple sets of pair-wise 3-D data are then merged and used for obtaining 3-D features which are then clustered into discrete 3-D objects that can lie on any arbitrary plane.
Claims13
A method for segmenting stereoscopic information into 3-D objects comprising the steps of:
- acquiring a set of multiple images of a scene substantially simultaneously and having a predetermined geometric relationship with each other;
- using a vision system to carry out the steps of:
- filtering each of said acquired multiple images to obtain multiple sets of features observed in each of said corresponding multiple images;
- processing at least two pairs of sets of features to generate at least two result sets according to matching features between members of each pair of sets of features;
- wherein the step of processing further includes the steps of:
- matching features from a right image and a left image to form a set of horizontal disparities;
- and matching features from a right image and a top image to form a set of vertical disparities, wherein said right and left images were obtained from image acquisition devices arranged along a horizontal line, and said right and top images were obtained from image acquisition devices arranged along a vertical line substantially perpendicular to said horizontal line;
- selecting features from said at least two result sets according to a predetermined orientation threshold;
- extracting 3-D features from said selected features;
- filtering said 3-D features according to location;
- and
- clustering any remaining 3-D features into discrete 3-D objects.
A method for segmenting stereoscopic information into 3-D objects comprising the steps of:
- acquiring a left image, a right image and a top image of a scene, using a trinocular image acquisition device;
- using a vision system to carry out the steps of:
- separately processing each of said left, right and top images to filter each image and to create corresponding sets of edge characteristics for each image;
- stereoscopically matching features between said right and left images to create a set of vertical feature matches, each having a disparity vector;
- stereoscopically matching features between said right and top images to create a set of horizontal feature matches, each having a disparity vector;
- selecting all features from the set of vertical feature matches having a disparity that is substantially vertical and discarding corresponding features from the set of horizontal matches, to obtain a combined set of selected vertical features and horizontal features;
- extracting a set of 3-D features from said combined set of features, based upon predetermined camera geometry;
- filtering said set of 3-D features to eliminate features corresponding to predetermined 3-D locations;
- and
- clustering said filtered set of 3-D features into a set of 3-D objects, according to discontinuities in a range dimension among successive 3-D points in a chain of points corresponding to a 3-D feature.
Dependencies are inferred from the claim text.