Christopher S Hassett

US Patent:

58570675, Jan 5, 1999

Filed:

Dec 23, 1993

Appl. No.:

8/172534

Inventors:

Christopher R. Hassett - Cupertino CA
Harry J. Collins - Cupertino CA
John W. Nogrady - Santa Clara CA

Assignee:

Adobe Systems, Inc. - Mountain View CA

International Classification:

G06T 1100

US Classification:

395150

Abstract:

A method and apparatus convert font outlines to rasterized bitmaps. The method accesses stored outline data representing an object in a first coordinate space and transforms the outline data to corresponding data representing the object in a second corrdinate space. Regional relationship information is maintained in both corrdinate spaces through a non-linear transformation expressed as a plurality of linear transformation matrices, and a bit map, suitable for displaying the object, is generated as a result of the transformation. The apparatus of the invention analyzes Bezier curves and subdivides them as necessary until each portion is sufficiently flat to be approximated as a straight line, and calculates where line segments cross pixel midlines in order to fill the outline, and then generates the bit map.

US Patent:

53012674, Apr 5, 1994

Filed:

Sep 27, 1991

Appl. No.:

7/767259

Inventors:

Christopher R. Hassett - Cupertino CA
Harry J. Collins - Cupertino CA
John W. Nogrady - Santa Clara CA

Assignee:

Adobe Systems Incorporated - Mountain View CA

International Classification:

G06F 1562

US Classification:

395150

Abstract:

The present invention provides an apparatus and method for converting font outlines to rasterized bit maps. The method accesses stored outline data representing the object in a first coordinate space and transforms the outline data to corresponding data representing the object in a second coordinate space, maintaining regional relationship information in both coordinate spaces, through a non-linear transformation expressed as a plurality of linear transformation matrices, to generate a bit map suitable for displaying the object. The present invention includes an apparatus to analyze Bezier curves and subdivide them as necessary until each portion is sufficiently flat to be approximated as a straight line, and then to calculate where line segments cross pixel midlines in order to fill the outline and generate the bit map. From another perspective, the method takes an outline of an object in a first coordinate space, scales the outline to a second coordinate space, identifies the coordinates of one or more select points in the second coordinate space and compares those coordinates with desired coordinates in the second coordinate space, calculates the difference in device space for the desired versus the actual coordinate in the second coordinate space, derives a plurality of piecewise linear transformation matrices to approximate a non-linear transformation, applies an appropriate linear transformation matrix to map essentially any point on the outline in the first coordinate space to corresponding coordinates in the second coordinate space, and fills and stores the outline of the object in a form suitable for display on a raster device.