US 6,151,411 AGranted

Point symmetry shaping method used for curved figure and point symmetry shaping apparatus thereof

AssigneeNEC Corporation

InventorShigeru Saito

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Abstract

In a point symmetry shaping apparatus used for a curved figure, any unrecorded symmetry figures are automatically shaped in a point symmetry manner within a short processing time. In the point symmetry shaping apparatus, a coordinate point which constitutes a symmetry center candidate point is calculated from all of center points of symmetry-judging-line-segments. A first point symmetry center candidate point/center point distance calculating unit calculates a distance between the symmetry center candidate point and the center point of the symmetry-judging-line-segment. A point symmetry judging unit judges a point symmetry of the input curved figure in such a manner that a calculation is made of a fluctuation value contained in the distances between the symmetry center candidate point and the center points of the symmetry-judging-line-segments, and the calculated fluctuation value is compared with a threshold value. A point symmetrizing processing unit corrects the coordinate values of the set of the intersection points between the curved line of the input curved figure and the grid, and also the coordinate values of the feature points in order to shape such an input curved figure having a point symmetry judged by the point symmetry judging unit in such a manner that the input curved figure having the point symmetry is positioned in a point symmetry manner with respect to the point symmetry center candidate point.

Claims36

Dependent claims

A point symmetry shaping apparatus of a curved figure, comprising:

feature point calculating means for calculating a plurality of feature points from a coordinate point series for tracing a trail of an input curved figure to thereby obtain the feature points of the input curved figure;
symmetry-judging-line-segment calculating grid producing means for producing a grid capable of involving said input curved figure based upon the feature points calculated by said feature point calculating means;
symmetry-judging-line-segment calculating means for calculating a set of said feature points and a set of intersection points between a curved line of said curved figure and the grid by tracing said feature points and said intersection points between the curved line and the grid from one of said plural feature points, and also for connecting the respective sets of said feature points to the respective sets of said intersection points by way of straight lines so as to produce a symmetry-judging-line-segment used to judge a point symmetry of said input curved figure;
judging line center point calculating means for calculating a coordinate value of a center point of said symmetry-judging-line-segment calculated by said symmetry-judging-line-segment calculating means;
first point symmetry center candidate point calculating means for calculating a coordinate point which constitutes a symmetry center candidate point from all of the center points calculated by said center point of symmetry-judging-line-segment calculating means;
first point symmetry center candidate point/center point distance calculating means for calculating a distance between said symmetry center candidate point and the center point of said symmetry-judging-line-segment;
point symmetry judging means for judging a point symmetry of said input curved figure in such a manner that a calculation is made of a fluctuation value contained in the distances between said symmetry center candidate point and the center points of said symmetry-judging-line-segments, calculated by said first center candidate point/center point calculating means, and said calculated fluctuation value is compared with a threshold value;
and
point symmetrizing processing means for correcting the coordinate values of said set of the intersection points between the curved line of said input curved figure and said grid, and also the coordinate values of the feature points in order to shape such an input curved figure having a point symmetry judged by said point symmetry judging means in such a manner that said input curved figure having the point symmetry is positioned in a point symmetry manner with respect to said point symmetry center candidate point.

6 more elements

A point symmetry shaping apparatus of a curved figure, comprising:

feature point calculating means for calculating a plurality of feature points from a coordinate point series for tracing a trail of an input curved figure to thereby obtain the feature points of the input curved figure;
symmetry-judging-line-segment calculating grid producing means for producing a grid capable of involving said input curved figure based upon the feature points calculated by said feature point calculating means;
symmetry-judging-line-segment calculating means for calculating a set of said feature points and a set of intersection points between a curved line of said curved figure and the grid by tracing said feature points and said intersection points between the curved line and the grid from one of said plural feature points, and also for connecting the respective sets of said feature points to the respective sets of said intersection points by way of straight lines so as to produce a symmetry-judging-line-segment used to judge a point symmetry of said input curved figure;
judging line center point calculating means for calculating a coordinate value of a center point of said symmetry-judging-line-segment calculated by said symmetry-judging-line-segment calculating means;
second point symmetry center candidate point calculating means for calculating a coordinate value of a center of a circumscribed rectangular shape of said input curved figure as a point symmetry center candidate point which constitutes a symmetry center candidate point;
second point symmetry center candidate point/center point distance calculating means for calculating a distance between said point-symmetry center candidate point and the center point of said symmetry-judging-line-segment;
point symmetry judging means for judging a point symmetry of said input curved figure in such a manner that a calculation is made of a fluctuation value contained in the distances between said point-symmetry center candidate point and the center points of said symmetry-judging-line-segments, calculated by said second center candidate point/center point calculating means, and said calculated fluctuation value is compared with a threshold value;
and
point symmetrizing processing means for correcting the coordinate values of said set of the intersection points between the curved line of said input curved figure and said grid, and also the coordinate values of the feature points in order to shape such an input curved figure having a point symmetry judged by said point symmetry judging means in such a manner that said input curved figure having the point symmetry is positioned in a point symmetry manner with respect to said point symmetry center candidate point.

6 more elements

A point symmetry shaping method of a curved figure, comprising:

a step for calculating a plurality of feature points from a coordinate point series for tracing a trail of an input curved figure to thereby obtain the feature points of the input curved figure;
a step for producing a grid capable of involving said input curved figure based upon the feature points calculated by said feature point calculating step;
a symmetry-judging-line-segment calculating step for calculating a set of said feature points and a set of intersection points between a curved line of said curved figure as and the grid by tracing said feature points and said intersection points between the curved line and the grid from one of said plural feature points, and also for connecting the respective sets of said feature points to the respective sets of said intersection points by way of straight lines so as to produce a symmetry-judging-line-segment used to judge a point symmetry of said input curved figure;
a symmetry-judging-line-segment calculating step for calculating a coordinate value of a center point of said symmetry-judging-line-segment calculated by said symmetry-judging-line-segment calculating step;
a first point-symmetry center candidate point calculating step for calculating a coordinate point which constitutes a symmetry center candidate point from all of the center points calculated by said center point of symmetry-judging-line-segment calculating step;
a first point symmetry center candidate point/center point distance calculating step for calculating a distance between said symmetry center candidate point and the center point of said symmetry-judging-line-segment;
a step for judging a point symmetry of said input curved figure in such a manner that a calculation is made of a fluctuation value contained in the distances between said symmetry center candidate point and the center points of said symmetry-judging-line-segments, calculated by said first center candidate point/center point calculating step, and said calculated fluctuation value is compared with a threshold value;
and
a step for correcting the coordinate values of said set of the intersection points between the curved line of said input curved figure and said grid, and also the coordinate values of the feature points in order to shape such an input curved figure having a point symmetry judged by said point symmetry judging means in such a manner that said input curved figure having the point symmetry is positioned in a point symmetry manner with respect to said point symmetry center candidate point.

6 more elements

A point symmetry shaping method of a curved figure, comprising:

a step for calculating a plurality of feature points from a coordinate point series for tracing a trail of an input curved figure to thereby obtain the feature points of the input curved figure;
a step for producing a grid capable of involving said input curved figure based upon the feature points calculated by said feature point calculating step;
a symmetry-judging-line-segment calculating step for calculating a set of said feature points and a set of intersection points between a curved line of said curved figure and the grid by tracing said feature points and said intersection points between the curved line and the grid from one of said plural feature points, and also for connecting the respective sets of said feature points to the respective sets of said intersection points by way of straight lines so as to produce a symmetry-judging-line-segment used to judge a point symmetry of said input curved figure;
a step for calculating a coordinate value of a center point of said symmetry-judging-line-segment calculated by said symmetry-judging-line-segment calculating step;
a second point symmetry center candidate point calculating step for calculating a coordinate value of a center of a circumscribed rectangular shape of said input curved figure as a point-symmetry center candidate point which constitutes a symmetry center candidate point;
a second point symmetry center candidate point/center point distance calculating step for calculating a distance between said point symmetry center candidate point and the center point of said symmetry-judging-line-segment;
a step for judging a point symmetry of said input curved figure in such a manner that a calculation is made of a fluctuation value contained in the distances between said point-symmetry center candidate point and the center points of said symmetry-judging-line-segments, calculated by said second center candidate point/center point calculating step, and said calculated fluctuation value is compared with a threshold value;
and
a step for correcting the coordinate values of said set of the intersection points between the curved line of said input curved figure and said grid, and also the coordinate values of the feature points in order to shape such an input curved figure having a point symmetry judged by said point symmetry judging means in such a manner that said input curved figure having the point symmetry is positioned in a point symmetry manner with respect to said point symmetry center candidate point.

6 more elements

Dependencies are inferred from the claim text.