Patent US5099435A successfully refreshed from Google Patents.
US5099435A
Expired / Lapsed
US
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Method and apparatus for conversion of outline characters to bitmap characters
Assignee: Imaging Holdings Corp
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Filing: 1989-03-31
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Granted: 1992-03-24
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Expires: 2009-03-31
Abstract
Abstract An outline representation of a character or symbol is treated as being composed of a set of zones formed in both the horizontal and vertical directions. The zones are completely character-specific. Each zone defines the extent of some feature of the character. The boundaries of the zones are mapped to specific pixel locations in a bitmap em-square of selected resolution and size. Additional interpolation zones are defined which are used to map all the points on the outline representation of the character that are contained within the interpolation zone, but do not coincide with a control edge, from the positions in the high-resolution em-square to a corresponding position in the low-resolution em-square. To maintain relationships between features, constraint functions may be defined which regulate the size of the control zones for a character at predetermined sizes. Control zones and interpolation zones are all derivatively linked to a basic set of horizontal and vertical control edges at the outline description level. Consequently, the number of computations needed is reduced and the speed with which a bitmap can be generated from the outline representation is increased.
Inventors
- 👤 John S. Collins
- 👤 Michael Yudis
- 👤 Philip G. Apley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:19
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/06; G09G1/14; G06; G06T; G06T11/00; G06T11/20; G06T11/23
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
134 words
A method for use in generating from an outline representation of a character a bitmap representation therefor, at a selectable point size and resolution, the outline representation being defined relative to a high-resolution em-square and the bitmap representation being defined in terms of a low resolution em-square, such method comprising the steps of: a) defining, for at least one dimension, a plurality of control zones, each having at least a starting control edge and an ending control edge, within the high-resolution em-square, each zone preferably corresponding to a typographic feature of the character; b) defining, for at least one dimension, a plurality of interpolation zones, each having at least a starting edge and an ending edge; c) arranging said interpolation zones to produce the best typographic quality in the bitmap representation of the character.
Claim 2
Independent Claim
134 words
A method for use in generating from an outline representation of a character a bitmap representation therefor, at a selectable point size and resolution, the outline representation being defined relative to a high-resolution em-square and the bitmap representation being defined in terms of a low resolution em-square, such method comprising the steps of: a) defining, for at least one dimension, a plurality of control zones, each having at least a starting control edge and an ending control edge, within the high-resolution em-square, each zone preferably corresponding to a typographic feature of the character; b) defining, for at least one dimension, a plurality of interpolation zones, each having at least a starting edge and an ending edge; c) arranging said interpolation zones to produce the best typographic quality in the bitmap representation of the character.
Claim 3
Dependent Claim
38 words
The method of claim 1 further comprising the step of: constraining at least one of said control zones to a predetermined size when the size of said bitmap representation of a character is smaller than a threshold size.
Claim 4
Dependent Claim
48 words
The method of claim 1 further comprising the step of simultaneously constraining at least one of said control zones of a plurality of one or more characters to a predetermined size when the size of said bitmap representation of said different characters is smaller than a second size.
Claim 5
Dependent Claim
42 words
The method of claim 3 further comprising the step of: for a character, constraining a plurality of control zones to a plurality of respective predetermined sizes when the size of the bitmap representation of the character is smaller than a threshold size.
Claim 6
Dependent Claim
20 words
The method of claim 4 further comprising the step of: arranging the respective predetermined control zone sizes in a hierarchy.
Claim 7
Dependent Claim
20 words
The method of claim 4 wherein the hierarchy is arranged according to the typographic importance of the respective control zone.
Claim 8
Dependent Claim
33 words
The method of claim 1 further comprising the step of: establishing for each of said control edges, a correspondence between its position in the high-resolution em-square and a position in the low-resolution em-square.
Claim 9
Dependent Claim
59 words
The method of claim 7 further comprising the step of: using each of said interpolation zones to establish a correspondence for each point on said outline representation of a character that is contained within an interpolation zone and does not coincide with a control edge, between their positions in the high-resolution em-square and a position in the low-resolution em-square.
Claim 10
Dependent Claim
44 words
The method of claim 7 or claim 8 wherein the low-resolution em-square comprises a finite number of pixels, and including the additional step of: rounding, to the nearest whole number of pixels, the number of pixels in each control zone in the low-resolution em-square.
Claim 11
Dependent Claim
41 words
The method of claim 7 wherein the low-resolution em-square comprises a finite number of pixels, and the step of establishing correspondence includes the step of: rounding, to the nearest whole pixel, the positions of the control edges in the low-resolution em-square.
Claim 12
Dependent Claim
47 words
The method of claim 7 wherein the low-resolution em-square comprises a finite number of pixels, and including the additional step of: allocating the pixels in the low-resolution em-square according to the relative sizes of the control zones for each dimension in the outline representation of the character.
Claim 13
Dependent Claim
30 words
The method of claim 11 further comprising the step of: rounding, to the nearest whole number of pixels, the number of pixels in each control zone in the low-resolution em-square.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein characters are represented in the high-resolution em-square by a combination of curves and straight lines.
Claim 15
Dependent Claim
11 words
The method of claim 13 wherein the curves comprises Bezier curves.
Claim 16
Dependent Claim
21 words
The method of claim 1 wherein the size of the character in the bitmap representation is less than twenty five points.
Claim 17
Dependent Claim
24 words
The method of claim 1 wherein the resolution of the character in the bitmap representation is less than six hundred resolution units per inch.
Claim 18
Dependent Claim
85 words
A digital font for use in generating a bitmap representation of a selected character from a digital representation of the outline of said character, comprising, in a digital storage medium having a plurality of locations capable of storing digital information: a first set of storage locations containing data representing x-oriented control zones, each zone corresponding to a typographic feature of the character; and a second set of storage locations containing data representing y-oriented control zones, each zone corresponding to a typographic feature of the character.
Claim 19
Dependent Claim
85 words
A digital font for use in generating a bitmap representation of a selected character from a digital representation of the outline of said character, comprising, in a digital storage medium having a plurality of locations capable of storing digital information: a first set of storage locations containing data representing x-oriented control zones, each zone corresponding to a typographic feature of the character; and a second set of storage locations containing data representing y-oriented control zones, each zone corresponding to a typographic feature of the character.
Claim 20
Dependent Claim
33 words
The digital font of claim 17 further having: a third set of storage locations containing data representing x-oriented interpolation zones; and a fourth set of storage locations containing data representing y-oriented interpolation zones.
Claim 21
Dependent Claim
43 words
The digital font of claim 17, further comprising: a fifth set of storage locations containing data representing constraint functions, each constraint function being associated with an indicator of a threshold size bitmap representation of the character for which the constrain function is operative.
Claim 22
Dependent Claim
33 words
The digital font of claim 19 wherein the data for at least one constraint function includes a control zone size, to which the control zone is set when the constraint function is operative.
Claim 23
Dependent Claim
15 words
The digital font of claim 19, wherein the constraint functions are arranged in a hierarchy.
Claim 24
Dependent Claim
18 words
The digital font of claim 21 wherein the hierarchy is organized according to typographic importance of character features.
Claim 25
Dependent Claim
15 words
The digital font of claim 17 wherein the storage locations are embodied in magnetic media.
Claim 26
Dependent Claim
16 words
The digital font of claim 17 wherein the storage locations are embodied in semiconductor memory media.
Claim 27
Dependent Claim
15 words
The digital font of claim 24 wherein the semiconductor memory media comprises a read-only memory.
Claim 28
Independent Claim
99 words
A method for converting a two-dimensional high-resolution outline representation of a character to a two-dimensional low-resolution bitmap representation of the character at a selectable point size and resolution including the steps of: a) breaking the character into a plurality of control zones oriented in each in each of the two dimensions, each control zone corresponding to a typographic feature; and b) mapping the typographic features, as a function of the information contained in the control zones in each of the two character dimensions, from the high resolution representation to the bitmap representation of the character at a selected size.
Claim 29
Independent Claim
99 words
A method for converting a two-dimensional high-resolution outline representation of a character to a two-dimensional low-resolution bitmap representation of the character at a selectable point size and resolution including the steps of: a) breaking the character into a plurality of control zones oriented in each in each of the two dimensions, each control zone corresponding to a typographic feature; and b) mapping the typographic features, as a function of the information contained in the control zones in each of the two character dimensions, from the high resolution representation to the bitmap representation of the character at a selected size.
Claim 30
Dependent Claim
38 words
The method of claim 26 wherein the step of mapping includes selecting, for each control zone, a scaling factor appropriate to map the extent of the control zone to an integral number of pixels in the bitmap representation.
Claim 31
Dependent Claim
73 words
The method of claim 26 further comprising the step of: providing a plurality of constraint functions, each constraint being operative for sizes below a threshold size bitmap representation of the character and for respectively constraining a size of a control zone corresponding to a typographic feature of the character to a predetermined size when the bitmap representation of the character is smaller than the threshold size for which the constraint function is operative.
Claim 32
Dependent Claim
34 words
The method of claim 28 further comprising the step of: arranging the plurality of constraint functions in a hierarchy according to the relative importance of the typographic feature respectively corresponding to each control zone.
Claim 33
Dependent Claim
50 words
The method of claim 29 further comprising the step of: simultaneously constraining to a predetermined size at least one control zone for each of a plurality of characters when the bitmap representation of one of the characters is smaller than the threshold size for which the constraint function is operative.
Claim 34
Independent Claim
131 words
A method for converting a two-dimensional high-resolution outline representation of a character to a two-dimensional low-resolution bitmap representation of the character at a selectable point size and resolution including the steps of: a) defining for the character, in at least one of the two dimensions, at least one control zone, each control zone corresponding to a typographic feature; and b) mapping the typographic features, as a function of the information contained in the control zones, from the high resolution representation to the bitmap representation of the character at a selected size, said mapping step including the steps of (1) scaling the control zone from its size in high-resolution outline units to a corresponding number of pixels in bitmap space, and (2) rounding said number of pixels to the nearest integer number.
Claim 35
Independent Claim
131 words
A method for converting a two-dimensional high-resolution outline representation of a character to a two-dimensional low-resolution bitmap representation of the character at a selectable point size and resolution including the steps of: a) defining for the character, in at least one of the two dimensions, at least one control zone, each control zone corresponding to a typographic feature; and b) mapping the typographic features, as a function of the information contained in the control zones, from the high resolution representation to the bitmap representation of the character at a selected size, said mapping step including the steps of (1) scaling the control zone from its size in high-resolution outline units to a corresponding number of pixels in bitmap space, and (2) rounding said number of pixels to the nearest integer number.
Claim 36
Dependent Claim
20 words
The method of claim 31 wherein the size of the character in the bitmap representation is less than twenty-five points.
Claim 37
Dependent Claim
24 words
The method of claim 31 wherein the resolution of the character in the bitmap representation is less than six hundred resolution units per inch.
Claim 38
Dependent Claim
132 words
In a computer processing system, a method for generating a two-dimensional low-resolution bitmap representation of a character at a selectable point size and resolution, from a two-dimensional high-resolution outline representation of the character including information defining for the character, in at least one of the two dimensions, at least one control zone, each control zone corresponding to a typographic feature, comprising mapping each typographic feature, as a function of the information contained in the corresponding control zone, from the high resolution representation to the bitmap representation of the character at the selected size, said mapping including the steps of (1) scaling the control zone from its size in high-resolution outline units to a corresponding number of pixels in bitmap space, and (2) rounding said number of pixels to the nearest integer number.
Claim 39
Dependent Claim
132 words
In a computer processing system, a method for generating a two-dimensional low-resolution bitmap representation of a character at a selectable point size and resolution, from a two-dimensional high-resolution outline representation of the character including information defining for the character, in at least one of the two dimensions, at least one control zone, each control zone corresponding to a typographic feature, comprising mapping each typographic feature, as a function of the information contained in the corresponding control zone, from the high resolution representation to the bitmap representation of the character at the selected size, said mapping including the steps of (1) scaling the control zone from its size in high-resolution outline units to a corresponding number of pixels in bitmap space, and (2) rounding said number of pixels to the nearest integer number.
Claim 40
Dependent Claim
20 words
The method of claim 34 wherein the size of the character in the bitmap representation is less than twenty-five points.
Claim 41
Dependent Claim
24 words
The method of claim 34 wherein the resolution of the character in the bitmap representation is less than six hundred resolution units per inch.
Claim 42
Dependent Claim
138 words
A computer processing system for generating a two-dimensional low-resolution bitmap representation of a character at a selectable point size and predetermined resolution, from a two-dimensional high-resolution outline representation of the character, comprising: a. memory media providing, for each such character, information defining for the character, in at least one of the two dimensions, at least one control zone, each control zone corresponding to a typographic feature; and b. means for mapping each typographic feature, as a function of the information contained in the corresponding control zone, from the high resolution representation to the bitmap representation of the character at the selected size, including means for (1) scaling the control zone from its size in high-resolution outline units to a corresponding number of pixels in bitmap space, and (2) rounding said number of pixels to the nearest integer number.
Claim 43
Dependent Claim
138 words
A computer processing system for generating a two-dimensional low-resolution bitmap representation of a character at a selectable point size and predetermined resolution, from a two-dimensional high-resolution outline representation of the character, comprising: a. memory media providing, for each such character, information defining for the character, in at least one of the two dimensions, at least one control zone, each control zone corresponding to a typographic feature; and b. means for mapping each typographic feature, as a function of the information contained in the corresponding control zone, from the high resolution representation to the bitmap representation of the character at the selected size, including means for (1) scaling the control zone from its size in high-resolution outline units to a corresponding number of pixels in bitmap space, and (2) rounding said number of pixels to the nearest integer number.
Claim 44
Dependent Claim
20 words
The method of claim 37 wherein the size of the character in the bitmap representation is less than twenty-five points.
Claim 45
Dependent Claim
24 words
The method of claim 37 wherein the resolution of the character in the bitmap representation is less than six hundred resolution units per inch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-24 | 1995-09-23 | 1996-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-24 | 1999-09-23 | 2000-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-24 | 2003-09-23 | 2004-03-24 | $7700.00 | Window Closed / Lapsed |