Stroke-based font generation independent of resolution

A character generating apparatus for generating character bitmap images in character bitmap space for display on an output device, wherein each generated character comprises a plurality of strokes, said apparatus further comprising:

• means for selecting a character for display on the output device, wherein each stroke comprise predefined, prestored key points, width values, curve ratios stored in a curve ratio table, and feature points that have a predefined spatial relationship to the key points and wherein a key point is labeled with hint information if the key point requires a predefined specific display location;
• means for determining the resolution of the output device;
• means for retrieving ratios values from the prestored curve level table according to the determined resolution of the output device;
• means for calculating non-labeled key point positions that are associated with the strokes of said selected character in the characters display space at the key points' prestored position;
• means for calculating labeled key point positions that are associated with the strokes of said selected character in the characters display space at predetermined positions relative to the bitmap cell that contains the labeled key points' prestored position;
• and
• means for rendering the strokes of the selected character in the character bitmap space on the output device according to the width values, the retrieved curve ratios, and feature points of the strokes and calculated, labeled and non-labeled key points.

A computer readable medium encoded with a data structure for generating character bitmap images in character bitmap space for display on an output device, wherein each generated character comprises a plurality of strokes, said computer readable medium further comprising:

• means for selecting a character for display on the output device, wherein each stroke comprise predefined, prestored key points, width values, curve ratios stored at different predefined levels of a tree type data structure, and feature points that have a predefined spatial relationship to the key points and wherein a key point is labeled with hint information if the key point requires a predefined specific display location;
• means for determining the resolution of the output device;
• means for retrieving ratios values from the prestored tree type data structure according to the determined resolution of the output device;
• means for calculating non-labeled key point positions that are associated with the strokes of said selected character in the characters display space at the key points' prestored position;
• means for calculating labeled key point positions that are associated with the strokes of said selected character in the characters display space at predetermined positions relative to the bitmap cell that contains the labeled key points' prestored position;
• and
• means for rendering the strokes of the selected character in the character bitmap space on the output device according to the width values, the retrieved curve ratios, and feature points of the strokes and calculated, labeled and non-labeled key points.

A computer graphical user interface tool for generating stroke-based fonts using stroke representation and stroke shape bitmap generation for displaying stroke-based fonts in a bitmap space, said interface tool includes an output device, processor and memory, said graphical user interface comprising:

• means for generating a set of basic strokes from an observed scanned set of master characters, wherein each basic stroke in the generated set of basic strokes includes key points and width values;
• means for labeling key points of basic strokes, wherein keypoints are labeled if said respective stroke requires rendering to a specific display location;
• means for defining a stroke shape formula for each basic stroke according to the key points and width values;
• means for defining feature points for each basic stroke according to said defined stroke shape formula;
• means for defining curve segments between said defined feature points, said means for defining curve segments between said defined feature points further comprising:
• means for generating curve ratios of second order Bezier curves between said defined feature points according to the outline of strokes in the observed scanned set of master characters;
• means for assigning the second order Bezier curve ratios to levels in a curve level table;
• and
• means for assigning the levels in the curve level table to ranges of bitmap resolutions;
• and
• means for storing key points, width values, the defined stroke shape formula, feature points and curve segments in said memory.

A method for generating stroke-based fonts using stroke representation and stroke shape bitmap generation for displaying stroke-based fonts in a bitmap space, said method comprising:

• generating a set of basic strokes from an observed scanned set of master characters, wherein each basic stroke in the generated set of basic strokes includes key points and width values;
• labeling key points of the basic strokes, wherein keypoints are labeled if said respective stroke requires rendering to a specific display location;
• defining a stroke shape formula for each basic stroke according to the key points and width values;
• defining feature points for each basic stroke according to said defined stroke shape formula;
• defining curve segments between said defined feature points, said defining curve segments between said defined feature points further comprises:
• generating curve ratios of second order Bezier curves between said defined feature points according to the outline of strokes in the observed scanned set of master characters;
• assigning the second order Bezier curve ratios to levels in a curve level table;
• and
• assigning the levels in the curve level table to ranges of bitmap resolutions;
• and
• storing key points, width values, the defined stroke shape formula, feature points and curve segments.