Feature recognition using loose gray scale template matching
AssigneeXerox Corporation
InventorsRobert P. Loce, John C. Handley, Clara Cuciurean-Zapan
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Abstract
What is presented is a method for feature recognition using loose-gray-scale template matching including at least an initial point for locating within the received image a plurality of pixel points in gray-scale surrounding an initial point. The method has the steps of first locating the initial point and the plurality of pixel points to define feature boundaries and then generating a looseness interval about the located initial point with template information being associated therewith. The next step involves determining which one of a plurality of templates for fitting fits within a threshold looseness interval, and then outputting a signal associated with that recognized feature.
Claims20
A method for feature recognition using a method for matching a plurality of templates with a received image comprising:
- (a) receiving an image comprised of gray-scale image data;
- (b) generating a two-dimensional window of the received gray-scale image data, the two-dimensional window having a target gray-scale pixel and a plurality of surrounding gray-scale pixels, each gray-scale pixel being associated with a pixel of received gray-scale image data in the two-dimensional window;
- (c) determining a plurality of looseness intervals for one template of a plurality of templates, each looseness interval being a difference between a gray-scale pixel associated with the two-dimensional window and a template gray scale pixel from the template and corresponding to the pixel location in the two-dimensional window;
- (d) determining a template looseness interval value for the template based upon the determined plurality of looseness intervals;
- (e) comparing the determined template looseness interval value to a threshold looseness interval value, the threshold looseness interval value being a maximum allowable value for the determined template looseness interval value that indicates a loosely matched template;
- (f) determining, based upon the comparison between the determined template looseness interval value and the threshold looseness interval, which template of the plurality of templates loosely matches the two-dimensional window of received gray-scale image data, the loosely matched template being a template wherein the determined template looseness interval value associated therewith is equal to a non-zero value and the threshold looseness interval value is equal to a non-zero value, an exactly matched template being a template wherein the associated determined looseness interval value is equal to a zero value and the threshold looseness interval value is equal to a zero value;
- and
- (g) outputting an identifier associated with the loosely matched template such that the identifier indicates a recognized image feature.
A method for feature recognition using a method for matching a plurality of templates with a received image comprising:
- (a) receiving an image comprised of gray-scale image data;
- (b) generating a two-dimensional window of the received gray-scale image data, the two-dimensional window having a target gray-scale pixel and a plurality of surrounding gray-scale pixels, each gray-scale pixel being associated with a pixel of received gray-scale image data in the two-dimensional window;
- (c) determining a plurality of looseness intervals for one template from a plurality of templates, each looseness interval being a difference between a gray-scale pixel associated with the two-dimensional window and a template gray scale pixel from the template and corresponding to the pixel location in the two-dimensional window;
- (d) comparing each non-zero looseness interval of the plurality of looseness intervals with a threshold looseness interval to determine a looseness interval number for the template, the looseness interval number being equal to how many non-zero looseness intervals within the set of looseness intervals are less than the threshold looseness interval;
- (e) selecting the template of the plurality of templates having a greatest associated looseness interval number as the template that loosely matches the two-dimensional window of received gray-scale image data;
- and
- (f) outputting an identifier associated with the loosely matched template such that the identifier indicates a recognized image feature.
Dependencies are inferred from the claim text.