Apparatus for recognition of drawn shapes or view types for automatic drawing input in CAD system
First Claim
1. An apparatus for recognition of shapes in drawings for automatic drawing input in a CAD system, said apparatus comprising:
- drawing reading means for producing image data including vectorized image data, based on reading of a drawing;
character recognition means for recognizing types of shapes and characters including lengths, angles, and the like of contour lines based on the image data and producing character recognition data based on said recognition;
line segment discrimination means for discriminating types of line segments in accordance with definitions assigned to each type of line segment based on the vectorized image data and producing line segment discrimination data based on said discrimination;
centerline extraction means for extracting centerlines drawn in center positions of shapes from the line segments discriminated by said line segment discrimination means based on the image data, the character recognition data, and the line segment discrimination data and producing centerline extraction data based on said extraction;
symmetry determination means, responsive to the image data and the centerline extraction data, for determining symmetry of a symmetrical shape based on intersections between the extracted centerlines and straight lines between endpoints of contour lines, distances between the endpoints of contour lines and the intersections, and angles between the centerlines and the straight lines between end points of contour lines and for producing symmetry data; and
figure recognition means, responsive to the image data and the symmetry data, for recognizing at least one of an undetermined shape, a length of an undetermined line segment, and a position of the undetermined line segment undiscriminated by the line segment discrimination means, using at least one of the symmetical shape and the length and position of one of the line segments discriminated by said line segment discrimination means, and the character recognition data from said character recognition means.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus for recognition of shapes in drawings for automatic drawing input in a CAD system including a centerline extraction unit for extracting centerlines drawn in center positions of shapes from the line segments discriminated by a line segment discrimination unit, a symmetry determination unit for determining symmetry of shapes based on intersections between the extracted centerlines and straight lines between end points of contour lines, distances between the endpoints of contour lines and the intersections, angles between the centerlines and the straight lines between endpoints of contour lines, and a shape recognition unit for recognizing, using the result of determination of the symmetry determination unit, a shape, a length of line segment, and a position of line segment not indicated by deriving the shape, the length of line segment, and the position of line segment from a shape, a length of line segment, and a position of line segment indicated, and characters recognized by a character recognition unit. In connection with this shape recognition apparatus, an apparatus is provided for recognition of views in drawings for automatic drawing input. Also, shape recognition apparatuses are provided for setting dimensional values known in other views or derived dimension values calculated on the basis of known dimensional values to contour lines, and for adding line segments by producing a line segment based on a matching check.
72 Citations
7 Claims
-
1. An apparatus for recognition of shapes in drawings for automatic drawing input in a CAD system, said apparatus comprising:
-
drawing reading means for producing image data including vectorized image data, based on reading of a drawing; character recognition means for recognizing types of shapes and characters including lengths, angles, and the like of contour lines based on the image data and producing character recognition data based on said recognition; line segment discrimination means for discriminating types of line segments in accordance with definitions assigned to each type of line segment based on the vectorized image data and producing line segment discrimination data based on said discrimination; centerline extraction means for extracting centerlines drawn in center positions of shapes from the line segments discriminated by said line segment discrimination means based on the image data, the character recognition data, and the line segment discrimination data and producing centerline extraction data based on said extraction; symmetry determination means, responsive to the image data and the centerline extraction data, for determining symmetry of a symmetrical shape based on intersections between the extracted centerlines and straight lines between endpoints of contour lines, distances between the endpoints of contour lines and the intersections, and angles between the centerlines and the straight lines between end points of contour lines and for producing symmetry data; and figure recognition means, responsive to the image data and the symmetry data, for recognizing at least one of an undetermined shape, a length of an undetermined line segment, and a position of the undetermined line segment undiscriminated by the line segment discrimination means, using at least one of the symmetical shape and the length and position of one of the line segments discriminated by said line segment discrimination means, and the character recognition data from said character recognition means.
-
-
2. An apparatus for recognition of views in drawings for automatic drawing input in a CAD system, said apparatus comprising:
-
drawing reading means for reading a drawing to produce drawing data including point information; vector forming means for receiving the drawing data from said drawing reading means and producing vector data by deriving line information from the point information in the drawing data; figure element separation means for receiving the vector data from said vector forming means and carrying out separation of figure elements in the vector data to produce separated figure element data; line type discrimination means for receiving the separated figure element data from said figure element separation means and carrying out discrimination of types of lines in the separated figure element data to produce line type discrimination data; and view discrimination means for receiving the line type discrimination data from said line type discrimination means and grouping contour lines, checking an inclusive relationship, counting a number of non-inclusive contour lines, and determining a view in accordance with a predetermined criteria in correspondence with the number of non-inclusive contour lines to produce a discrimination conclusion concerning the views. - View Dependent Claims (3)
-
-
4. An apparatus for recognition of shapes in drawings for automatic drawing input in a CAD system, said apparatus comprising:
-
classification means for classifying data of a drawing into character data and line segment data; character discrimination means for receiving the character data from said classification means and discriminating types of shapes and characters based on the character data to produce character discrimination data; line segment discrimination means for receiving the line segment data from said classification means and discriminating types of line segments to produce line segment discrimination data, the types of line segments include one of a contour line and a supplementary line; correspondence determination means for receiving the character discrimination data and the line segment discrimination data respectively from said character discrimination means and said line segment discrimination means and for determining correspondence between the character discrimination data and the line segment discrimination data; view discrimination means for receiving the line segment discrimination data from said line segment discrimination means and discriminating a view by grouping contour lines for each view too produce view discrimination data; vertex determination means for receiving the view discrimination data from said view discrimination means and determining vertexes of the contour lines; first dimension setting means for receiving data from said correspondence determination means and said vertex determination means and setting dimensional values to the contour lines corresponding to portions of views having indications of dimensions; dimension calculation means for receiving data from said first dimension setting means and calculating dimensional values of the contour lines of portions without indications of dimensions using known dimensional values; and second dimension setting means for receiving data from said dimension calculation means and, utilizing correspondence between views in accordance with a projection system, setting the dimensional values known in another one of the views or the dimensional values calculated in said dimension calculating means on the basis of the known dimensional values to the contour lines of the view.
-
-
5. An apparatus for recognition of shapes in drawings for automatic drawing input in a CAD system, said apparatus comprising:
-
contour line discrimination means for discriminating contour lines in drawings; view discrimination means for discriminating views in drawings; data storage means for receiving data from said contour line discrimination means and said view discrimination means and storing the data received; vertex acquisition means for receiving data from said data storage means, confirming the contour lines on X and Y axes, and deriving coordinates of endpoints of the contour lines; matching check means for receiving data from said vertex acquisition means and pattern data from a knowledge base, comparing the views based on correspondence between positions of vertexes of the contour lines and position identification numbers of the vertexes to detect contradictory portions and storing results of the comparison as match data; and line segment addition means for receiving the match data from said matching check means and, when a contradictory portion is detected, selecting a particular type of line segment to be supplemented to a view having a vertex not satisfying the correspondence of said matching check means, producing a line segment of the particular type, and adding the line segment to the drawing produced. - View Dependent Claims (6, 7)
-
Specification