US 5,291,186 AGranted

Method and apparatus for minimizing the visual degradation of digital typefaces-diagonal adjustment

AssigneeSun Microsystems, Inc.

InventorsEduardo Martinez, May Kao

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Abstract

A method and apparatus for minimizing the visual degradation of a typeface wherein the need for the manual input of skilled technicians is eliminated and the important visual components of each character and the relationship of the visual components of each character with the other characters of the typeface are preserved. The characters are analyzed to determine the visual components in the horizontal and vertical direction which comprise each character and the priority of adjustment. Using the visual components determined, starting with the highest priority component, the coordinates describing each character are adjusted according to rules which are dependent upon whether the strokes formed are oriented in the horizontal or vertical direction. The adjustment of the lower priority visual components is dependent on the previously aligned components. The important visual components in the diagonal direction are subsequently adjusted in accordance with similar sized visual components in the horizontal and vertical direction wherein the dimensions of the adjusted horizontal and vertical components are maintained.

Claims14

Dependent claims

In a computer system comprising a display for displaying characters of a digital typeface, a method for enhancing the legibility of the characters of the digital typeface, said process comprising the steps of:

ordering all diagonal segments by their slopes, said diagonal segments formed by frames points of frames representing the characters, said frame points having X-Y coordinate pairs, each of said characters being defined by a plurality of control points having X-Y coordinate pairs, said frame points of each character forming a polygon and having determinable geometric relationships with said control points of the character based on their coordinates;
forming groups of diagonal segments which are relatively close in angle;
rotating each group of diagonal segments by the complement of the average slope of the group such that the diagonal segments are approximately vertical;
identifying certain pairs of diagonal master segments as diagonal strokes if the two segments oppose one another in direction and, vertically overlap one another and the ratio of the length of vertical overlap and the distance between segments is greater than a predetermined amount indicative of the visual recognition of a stroke;
adjusting the thickness of the diagonal strokes according to the adjusted thicknesses of horizontal or vertical strokes which were the same or approximately the same thickness prior to adjustment;
adjusting the frame points of the diagonal strokes to correspond to the adjusted thickness of the diagonal stroke, wherein the thicknesses of adjacent strokes are preserved by displacing the frame points along the segments of the adjacent strokes.

3 more elements

In a computer system comprising a display for displaying characters of a digital typeface, an apparatus for implementing a method for enhancing the legibility of the characters of the digital typeface, said apparatus comprising:

means for executing a program routine to order all diagonal segments by their slopes, said diagonal segments formed by frame points of frames representing said characters, said frame points having X-Y coordinate pairs, each of said characters being defined by a plurality of control points having X-Y coordinate pairs, said frame points of each character forming a polygon and having determinable geometric relationships with said control points of the character;
means for executing a program routine to form groups of diagonal segments which are relatively close in angle;
means for executing a program routine to rotate each group of diagonal segments by the complement of the average slope of the group such that the diagonal segments are approximately vertical;
means for executing a program routine to identify certain pairs of diagonal master segments as diagonal strokes if the two segments oppose one another in direction and, vertically overlap one another and the ratio of the length of vertical overlap and the distance between segments is greater than a predetermined amount indicative of the visual recognition of a stroke;
means for executing a program routine to adjust the thickness of the diagonal strokes according to the adjusted thicknesses of horizontal or vertical strokes which were the same or approximately the same thickness prior to adjustment;
means for executing a program routine to adjust the frame points of the diagonal strokes to correspond to the adjusted thickness of the diagonal stroke, wherein the thicknesses of adjacent strokes are preserved by displacing the frame points along the segments of the adjacent strokes.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/846,584Filed 5 Mar 1992 · division
Priority: 26 Oct 1988
Granted: 1 Mar 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G09G 5/28
Generation of individual character patterns: for enhancement of character form, e.g. smoothing
G06K 15/02
Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printers: using printers
G06T 11/23
Drawing from basic elements: using straight lines or curves
G09G 1/14
Using single beam tubes , e.g. three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows:…