Computer graphics processing and selective visual display system – Computer graphics processing – Character generating
Reexamination Certificate
1998-10-26
2001-09-11
Luu, Matthew (Department: 2672)
Computer graphics processing and selective visual display system
Computer graphics processing
Character generating
C345S471000, C345S472000
Reexamination Certificate
active
06288725
ABSTRACT:
TECHNICAL FIELD
This invention is in the field of information processing technology and specifically is in the field of character information processing.
SUMMARY OF THE INVENTION
The compression and the restoration of information for Chinese character (Hanzi) fonts is an important subject in a field which needs to be studied and optimized. An improved representation method and restoration method of font information must possess simultaneous advantages, such as high restoration accuracy, high ratio of overall compression, high restoration speed and simplicity of font design. The current technologies are not able to meet these requirements simultaneously. Hanzi (Chinese characters) are abundant in both numbers and character fonts. For instance, Song Ti has many different styles, such as Writing Song (Shu Song), Newspaper Song (Bao Song), Title Song (Biao Ti Song) and Black Song (Hei Song); they all have similar font and stroke relationships but are differentiated from each other in stroke width, horizontal and vertical stroke width ratio and shape of stroke tip. In this case, Song Ti is called the primary font and the various fonts derived from the primary font are called the variants of the font.
According to the conventional methods, each variant is a set of new fonts and a set of fonts cannot be enlarged or reduced within an overly wide range. So that, when restoring small sized fonts, it could result in various distortions, such as strokes merging together, uneven stroke separation, inconsistency in stroke width, or loss of stroke tip. And when restoring large fonts, the strokes appear to be thin and the shape of stroke tips is not sufficiently fine sometimes provided for the small, medium and large sized characters respectively for one font type. This has multiplied the font information volume. Sometimes, the use of hint information to avoid the distortion of small sized characters also increases the font volume and makes the design more complicated.
In the advertisement and publishing industry, there are more and more fonts and font sets, requiring a processing capacity of a 30,000 to 60,000 character set. In these cases of Hanzi information processing, requiring various kinds of fonts, various sizes of characters, extra-large character sets and fonts of high accuracy, even when using the existing character representation method with a relatively high compression ratio, the font information volume is still extremely large. Improving the accuracy also increases the font volume. Therefore, fonts are required to not only have high compression ratios but also high enough accuracy. Three types of compression ratio must be comprehensively increased: Single font set compression ratio; variant consolidation compression ratio, that is to make a design putting various font variants with different stroke widths and stroke tips into one font set, and scaling overlay ratio, that is to maintain sufficient accuracy when changing sizes within a wide range. Among the above three, the variant consolidation compression ratio contributes the most to the total compression ratio and can reduce the design work load of a font set by many times over.
Presently, Bezier curves are usually used to represent cursive outlines (See “Postscript Language Reference Manual”, by Adobe System Corporation, published by Addison-Wesley publishing house, the second edition, 1990. P393). This method does not have a high enough compression ratio, strokes cannot be widened, it also requires additional hint information and the font design is complicated.
Chinese patent CN1076036A(1) (Sep. 8, 1993 publication) presented a representation and restoration method of font information which presently has the highest compression ratio with the standardly split jointed font in a single font set. Using this method, the accuracy of the whole font set can be increased by increasing the representation accuracy of a few character bases, while the character bases can be represented through other suitable methods. This method requires a font representation and restoration method with controllable stroke width to represent the character bases. Its variant consolidation ratio and scaling overlay ratio depends on the character representation and restoration method used. The disadvantage of the method is that when restoring fonts using the space occupation factor proportion method, the binding between some character elements is somewhat too tight or too loose, and this is especially obvious when changing the stroke width. Use of a character element fine adjustment method will increase the font information volume. Meanwhile, because the different stroke skeleton points in the font are related to each other, when doing fine adjustment on one stroke, it is necessary to adjust the other related strokes, which will thus increase the fine adjustment information volume as well as the difficulty of the design.
According to the method in Chinese patent CN88100794A(2) (Sep. 7, 1988 publication), font information is composed of the following four parts: 1. Stroke type identification and the number and coordinates of skeleton points. 2. Stroke width. 3. Start-stop edge angle. 4. Stroke shape coefficient. At the time of restoration, the outline control point of each stroke is obtained from the above stated four types of data and the control points are connected with each stroke type according to a pre-selected method to obtain the line of outline of each stroke. The advantage is that the stroke width, the start-stop angle and the stroke tip can be controlled separately; that the stroke tip and angle can be changed only by changing the stroke tip data of the type 3 and type 4 related above; that the stroke width can be changed in a proportion which is different from the scaling proportion; and that it can produce fonts of high accuracy. The disadvantage is that the font set needs to be designed character by character; one font set can not produce many sets of fonts with larger stroke width and style differences; horizontal and vertical stroke width ratio can not be controlled separately, and one cannot prevent the strokes from merging together or avoid an uneven stroke gap. Distortion will occur especially when making strokes wider. See FIG.
15
.
FIG. 15
shows a font of “Jiu” after its strokes have been simply widened. The dotted lines
1509
in the figure are the edge lines of the reference font with reference stroke width [
1501
].
1503
is the frame line of the font.
1507
is the left skeleton point of the upper stroke “Heng” (horizontal stroke).
1508
is the upper skeleton point of the left “Shu” (vertical stroke).
1501
and
1504
are the widths of the vertical and horizontal strokes respectively before they were widened. The excess portion
1506
of the stroke outline beyond the frame line, the vacant region
1505
occurring at the stroke joining point, a width difference
1502
between the top and bottom ends of the left hand “Shu” (vertical stroke), and the outer edge of the upper and lower strokes of the “Ri” on the right side can be observed. The opposite situation will appear when simple stroke narrowing is done. All these distortions are not acceptable. The Chinese patent CN88102466A (3) (Apr. 9, 1988 publication) presented a stroke widening method, which adds an additional stroke widening direction angle and widening widths to either side of the skeleton line and allows the widening on the two sides of the stroke skeleton line to be done with different widths at the time of restoration. This may cause another kind of distortion. Taking
FIG. 15
as an example as above, if the right side of the left “Shu” (vertical) stroke is widened more than the left side in order to keep this stroke within the frame line, it may be caused to be overly close to or merge together with the “Ri” on the right side. The processes currently known in the art are not able to solve the problems stated above.
The Chinese patent CN1105762A (4) (Jul. 26, 1995 publication) explained the representation and restoration method of Chinese character (Ha
Havan Thu-Thao
Luu Matthew
LandOfFree
Representation and restoration method of font information does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Representation and restoration method of font information, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Representation and restoration method of font information will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2453193