Patent US5600772A successfully refreshed from Google Patents.
US5600772A
Expired / Lapsed
US
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Bit map character convertor using chain-codes for the character filling process
Assignee: Printronix LLC
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Filing: 1994-08-17
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Granted: 1997-02-04
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Expires: 2014-08-17
Abstract
Abstract A data converting apparatus and process for converting outline representations of a character into its bit mapped form using two buffers one being for the bit mapped form of the character symbol and the other for the chain-code representation of the outline of the character are disclosed. Three steps are utilized in the process. The first step draws the character outline on to the drawing buffer and generates the chain-code representation with flags to indicate contour collisions. The contours are then scanned one more time to add missing flags on the chain-code representation. Finally, the inside part of the contour on the drawing buffer is filled using the chain-code representations of the contour, to provide a filled character.
Inventors
- 👤 Hao Zhou
- 👤 Le Jun Shao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:04
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/14; G06T; G06T11/00; G06T11/40
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
104 words
A process for converting outlined representations of a character into its bit mapped form to form a character font comprising: providing a first buffer for a bit map form of a character; providing a second buffer for a chain-code representation of the outline of the character; drawing the outline of the character into the first buffer: generating chain-code representations of contour of the character; setting flags in chain-code in said second buffer to indicate contour collisions; scanning the contours of the chain-code representations to add missing chain-code flags; scanning and filling the inside part of the contour of the character; and, printing said character.
Claim 2
Dependent Claim
104 words
A process for converting outlined representations of a character into its bit mapped form to form a character font comprising: providing a first buffer for a bit map form of a character; providing a second buffer for a chain-code representation of the outline of the character; drawing the outline of the character into the first buffer: generating chain-code representations of contour of the character; setting flags in chain-code in said second buffer to indicate contour collisions; scanning the contours of the chain-code representations to add missing chain-code flags; scanning and filling the inside part of the contour of the character; and, printing said character.
Claim 3
Dependent Claim
17 words
The process as claimed in claim 1 further comprising: rasterizing a font component which has multiple components.
Claim 4
Dependent Claim
33 words
The process as claimed in claim 2 further comprising: reading a complete curve description of one component; rasterizing the curve description; and, then reading the next component and rasterizing it in sequential order.
Claim 5
Dependent Claim
21 words
The process as claimed in claim 3 further comprising: drawing a Bezier curve during the rasterizing process for describing the character.
Claim 6
Dependent Claim
18 words
The process as claimed in claim 4 further comprising: describing the Bezier curve segments in a constant direction.
Claim 7
Dependent Claim
35 words
The process as claimed in claim 5 further comprising: initiating the chain-code with a starting pixel with four bits used to represent one node, three bits for direction, and a starting bit for a flag.
Claim 8
Dependent Claim
16 words
The process as claimed in claim 6 further comprising: indicating contour collision points with chain-code flags.
Claim 9
Dependent Claim
80 words
The process of providing a bit map through character conversion for a font of a particular character comprising: converting a curve description of contours of the character into their bit mapped descriptions and chain-code descriptions; setting flags on the chain-code description to avoid over-filling and under-filling; curtailing over-filling by establishing a differential between a parametric description and the pixel description of the outline of the font; and, filling an interior portion of the contour to obtain the bit mapped font.
Claim 10
Dependent Claim
80 words
The process of providing a bit map through character conversion for a font of a particular character comprising: converting a curve description of contours of the character into their bit mapped descriptions and chain-code descriptions; setting flags on the chain-code description to avoid over-filling and under-filling; curtailing over-filling by establishing a differential between a parametric description and the pixel description of the outline of the font; and, filling an interior portion of the contour to obtain the bit mapped font.
Claim 11
Dependent Claim
19 words
The process as claimed in claim 8 further comprising: scanning only the inside of the contour of said font.
Claim 12
Dependent Claim
23 words
The process as cIaimed in claim 8 further comprising: establishing the filling direction based on a direction of the contours of the font.
Claim 13
Dependent Claim
29 words
The process as claimed in claim 8 further comprising: providing a first memory buffer for a image of the font; and, providing a second buffer for the chain codes.
Claim 14
Dependent Claim
30 words
The process as claimed in claim 11 wherein: said first buffer is equal to or greater than the biggest character to be printed with one bit for each respective pixel.
Claim 15
Dependent Claim
56 words
The process of filling components of a font for producing a character in a printing process comprising: generating the font outline on a drawing buffer: generating chain-code descriptions of the outline; providing chain-code flags to avoid contour collisions; adding missing chain-code flags; and, filling an inside portion of the contours of the components on the font.
Claim 16
Dependent Claim
56 words
The process of filling components of a font for producing a character in a printing process comprising: generating the font outline on a drawing buffer: generating chain-code descriptions of the outline; providing chain-code flags to avoid contour collisions; adding missing chain-code flags; and, filling an inside portion of the contours of the components on the font.
Claim 17
Dependent Claim
30 words
The process as claimed in claim 13 further comprising: providing direction vectors between successive curve pixels that are to be encoded when generating the font outline on the drawing buffer.
Claim 18
Dependent Claim
19 words
The process as claimed in claim 14 wherein: the drawing buffer draws Bezier curves by using Bezier curve decomposition.
Claim 19
Dependent Claim
18 words
The process as claimed in claim 14 further comprising: maintaining chain-code values through at least a second buffer.
Claim 20
Dependent Claim
26 words
The process as claimed in claim 14 further comprising: providing a corresponding chain-code for each newly generated outline pixel for a respective component of the character.
Claim 21
Dependent Claim
27 words
The process as claimed in claim 17 further comprising: setting a chain-code flag to indicate a collision of pixels which have been drawn on the drawing buffer.
Claim 22
Dependent Claim
36 words
The process as claimed in claim 18 further comprising: choosing a pixel at the starting point of the drawing buffer; traversing the chain-code backwards to check for missing chain-code flags; and, establishing any contour collisions thereby.
Claim 23
Dependent Claim
26 words
The process as claimed in claim 14 further comprising: detecting and marking collision chain-code flags; setting additional chain-code flags to avoid over-filling; and, filling said font.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-04 | 2000-08-05 | 2001-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-04 | 2004-08-05 | 2005-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-04 | 2008-08-05 | 2009-02-04 | $7700.00 | Window Closed / Lapsed |