A method and apparatus for constructing, storing and displaying characters

Claim 2

A computer system for creating graphic characters for display on a video screen, comprising: display means (100) for displaying a graphic character at a plurality of different degrees of resolution; means for determining the shape of the displayed graphic characters for said displayed degrees of resolution by changing pixels forming the graphic character displayed for the higher of said plurality of degrees of resolution; and storage means (102) for storing the graphic character for the higher resolution.

Claim 3

The computer system set forth in claim 1 wherein the graphic character for the higher resolution is stored as a bitmap.

Claim 4

The computer system set forth in claim 1 wherein the graphic character for the higher resolution is stored as coefficients for spline curves as a function of the boundary of the graphic character.

Claim 5

The computer system set forth in claim 1 wherein the displayed plurality of degrees of resolution comprises high, medium, and low degrees of resolution, and the displayed character corresponding to the medium resolution has approximately one-fourth of the pixels of the graphic character corresponding to the high resolution, and the graphic character corresponding to the low resolution has approximately one-fourth of the pixels of the graphic character corresponding to the medium resolution.

Claim 8

The method set forth in claim 5 wherein the graphic character for the higher resolution is stored as a bitmap.

Claim 9

The method set forth in claim 5 wherein the graphic character for the higher resolution is stored as coefficients for spline curves as a function of the boundary of the graphic character.

Claim 10

The method set forth in claim 5 wherein the graphic character for at least two resolutions is stored as bitmaps.

Claim 11

The method set forth in claim 5 wherein the graphic character for at least two resolutions is stored as coefficients for spline curves as a function of the boundary of the graphic character.

Claim 12

The method set forth in claim 5 wherein said displayed graphic character has three degrees of resolution, high, medium, and low, such that the graphic character corresponding to the medium resolution has approximately one-fourth of the pixels of the graphic character corresponding to the high resolution, and the graphic character corresponding to the low resolution has approximately one-fourth of the pixels of the graphic character corresponding to the medium resolution.

Claim 13

The method set forth in claim 5 wherein the step to determine the shape of the graphic character includes changing the pixels of the higher resolution character to cause the higher resolution character to coincide with the boundary between pixels at the lower resolution.

Claim 14

The method set forth in claim 5 wherein the step of determining the shape of the graphic character includes selecting curve portions of said character to fit pixel transitions in a ratio of 1 to integers, not greater than 3.

Claim 15

The method set forth in claim 5 wherein the step of determining the shape of the graphic character includes selecting curve portions of said character to fit pixel transitions in a ratio of integers, not greater than 3, to 1.

Claim 16

A computer system for displaying graphic characters on a video screen, comprising: storage means (102) for storing graphic characters as coefficients for spline curves which are a function of the boundaries of the respective graphs characters; conversion means for converting said coefficients to form a pixelmap of the character, said pixelmap including gray scale values from full on to full off for pixels at points along the boundary of the displayed graphic character; and display means (100) for displaying said formed pixelmap.

Claim 17

A computer system for displaying graphic characters on a video screen, comprising: storage means (102) for storing graphic characters as coefficients for spline curves which are a function of the boundaries of the respective graphs characters; conversion means for converting said coefficients to form a pixelmap of the character, said pixelmap including gray scale values from full on to full off for pixels at points along the boundary of the displayed graphic character; and display means (100) for displaying said formed pixelmap.

Claim 18

The computer system set forth in claim 14 wherein the conversion means includes means for selectively scaling said spline coefficients for determining the size of the displayed graphic character.

Claim 19

The computer system set forth in claim 14 wherein said coefficients correspond to straight lines and curved lines, and said gray scale values correspond to said coefficients.

Claim 20

The computer system set forth in claim 14, further comprising: means for assigning to said characters field designations corresponding to distinct character shapes, said field designations being fewer in number than the characters to be displayed; and means for determining the spacing between adjacent characters in accordance with said field designations.

Claim 21

The computer system set forth in claim 14 wherein the display means (100) includes: means for displaying the pixelmap in a selected color against a background having a different selected color ; means for mixing the character color and the background color for each boundary pixel in accordance with the gray scale value of the pixel.

Claim 24

The method set forth in claim 19 wherein the step of converting said coefficients further comprises the step of selectively scaling said coefficients for determining the size of the displayed graphic character.

Claim 25

The method set forth in claim 19 wherein said coefficients correspond to straight lines and curved lines, and said gray scale values correspond to said coefficients.

Claim 26

The method set forth in claim 19 further comprising the steps of: assigning to said characters field designations corresponding to distinct character shapes, said field designations being fewer in number than the characters to be displayed; and determining the spacing between adjacent characters in accordance with said field designations.

Claim 27

The method set forth in claim 19 wherein the step of displaying the pixelmap further comprises the steps of: displaying the pixelmap in a selected color against a background having a different colour; mixing the character color and the background color for each boundary pixel in accordance with the gray scale value of the pixel.

Claim 28

A computer system for displaying graphic characters on a video screen, comprising: storage means ( 102 ) for storing pixelmaps corresponding to graphic characters, said pixelmaps including gray scale values from full on to full off for pixels at points along the boundaries of the stored graphic characters; and display means (100) for displaying the pixelmaps of a respective graphic character in a selected color against a background having a different selected color means for mixing the character color and the background color for each boundary pixel in accordance with the gray scale value of the pixel.

Claim 29

A computer system for displaying graphic characters on a video screen, comprising: storage means ( 102 ) for storing pixelmaps corresponding to graphic characters, said pixelmaps including gray scale values from full on to full off for pixels at points along the boundaries of the stored graphic characters; and display means (100) for displaying the pixelmaps of a respective graphic character in a selected color against a background having a different selected color means for mixing the character color and the background color for each boundary pixel in accordance with the gray scale value of the pixel.

Claim 30

The computer system set forth in claim 24 further comprising: means for assigning to said characters field designations corresponding to distinct character shapes, said field designations being fewer in number than the characters to be displayed; and means for determining the spacing between adjacent characters in accordance with said field designations.

Claim 33

The method set forth in claim 26 further comprising the steps of: assigning to said characters field designations corresponding to distinct character shapes, said field designations being fewer in number than the characters to be displayed; and determining the spacing between adjacent characters in accordance with said field designations.

Claim 34

A computer system, comprising: means (100) for initially displaying graphic characters having at least two different degrees of resolution; means for determining the shape of said characters for said different degrees of resolution by changing the pixels of corresponding characters having the higher resolution; means for generating coefficients of spline curves for determining boundaries of said higher resolution characters; storage means (102) for storing said spline curve coefficients; means for selectively scaling said stored coefficients for generating pixelmaps in accordance with said scaled coefficients; means for generating a pixelmap from coefficients corresponding to each character; said pixelmap having gray scale values for each boundary pixel corresponding to the percentage of such pixel within the boundary as determined by said spline curve coefficients; and means for displaying pixelmaps for said characters in accordance with the selected scaled coefficients.

Claim 35

A computer system, comprising: means (100) for initially displaying graphic characters having at least two different degrees of resolution; means for determining the shape of said characters for said different degrees of resolution by changing the pixels of corresponding characters having the higher resolution; means for generating coefficients of spline curves for determining boundaries of said higher resolution characters; storage means (102) for storing said spline curve coefficients; means for selectively scaling said stored coefficients for generating pixelmaps in accordance with said scaled coefficients; means for generating a pixelmap from coefficients corresponding to each character; said pixelmap having gray scale values for each boundary pixel corresponding to the percentage of such pixel within the boundary as determined by said spline curve coefficients; and means for displaying pixelmaps for said characters in accordance with the selected scaled coefficients.

Claim 36

A computer system according to claim 28 wherein said stored spline coefficients which correspond to the vertical and horizontal boundaries of the graphic character coincide with the boundary between pixels.

Claim 37

A computer system according to claim 28 further comprising: means (lu2) for storing for each character a left and right field shape, said field shapes being less than the total characters to be displayed; means (102) for storing a proportional spacing value for each left and right field shape; and means for determining the space between characters in accordance with said proportional spacing value.

Claim 40

A method according to claim 31 wherein said stored spline coefficients which correspond to the vertical and horizontal boundaries of the graphic character coincide with the boundary between pixels.

Claim 41

A method according to claim 31 further comprising the steps of: storing for each character a left and right field shape, said field shapes being less than the total characters to be displayed; storing a proportional spacing value for each left and right field shape; and determining the space between characters in accordance with said proportional spacing value.