CN1076042A

CN1076042A - The mixed-spline functional based method of Chinese character contour is described

Info

Publication number: CN1076042A
Application number: CN 93102573
Authority: CN
Inventors: 陈中欣; 张翔钧; 张建伟; 黄建新
Original assignee: XIANFENG ELECTRONIC TECHNOLOGY Co HAIDIAN DISTRICT BEIJING
Current assignee: XIANFENG ELECTRONIC TECHNOLOGY Co HAIDIAN DISTRICT BEIJING
Priority date: 1993-03-15
Filing date: 1993-03-15
Publication date: 1993-09-08

Abstract

The present invention relates to a kind of descriptor handles with the mixed-spline functional based method of Chinese character contour and realizes the hardware technology of this method.This method comprises the steps:

A) each Chinese character is splitted into a plurality of strokes, it is characterized in that:

B) edge of each stroke is divided into several smooth section,

C) for each smooth section, with each point on the mixed-spline function representation curve of following form:

A+BU+CU ²(0≤U≤1)

P(U)＝D+EU+FU ²+GU ³(1≤U≤2)

H+IU+JU ²(2≤U≤3)

Wherein: P represents the position vector of each point on the curve; U is real parameter; A, B ..., J is a coefficient vector, three sample point coordinate values that can be from the curve and derivative value are calculated.

Description

The mixed-spline functional based method of Chinese character contour is described

The present invention relates to a kind of descriptor handles with the mixed-spline functional based method of Chinese character contour and realizes the hardware technology of this method.

Flourish along with Chinese character information industry, various technology of Chinese character arise at the historic moment.A wherein vital description that technology is exactly a Chinese character pattern.

Each stage of describing profile from full dot matrix to vector has been experienced in the description of Chinese character pattern, and domestic and international state-of-the-art technology has entered the stage of function representation profile at present, promptly selects certain function representation Chinese character contour for use.This method have describe true to nature, lively, multiple advantages such as Information Compression is than big, and the font distortion is undistorted, but the performance of these advantages is depended on to a great extent and adopted which type of function to describe Chinese character contour.Present most method all is to indiscriminately imitate external a kind of successful methods of describing the western language character contour, promptly adopts the Bezier function to describe the Chinese character pattern profile.

The equation of each point is on the Bezier curve:

Wherein n is that the polygonal number of Bezier curve controlled subtracts 1, and Pi is the position vector on each each summit of control polygon, and

B _i，n（u）＝ (n！)/(i！（1-u）！) （1-u） ^n-iu ⁱ（i＝0，1，...，n）

Though the Bezier curve has many good qualities and successfully described the western language font, when using it for Chinese character pattern and describing,, just show many weak points then because the complicacy of Chinese character (font is very abundant, font complex structure, the form of a stroke or a combination of strokes changeful).Such as, when the very big and other end curved transition of an end curved transition of smooth lines is very little, just be difficult to describe with the Bezier curve; And for example, still tangent or bigger redundant information is arranged after just can not guaranteeing to reduce when two tangent smooth lines are used the Bezier curve description respectively at tangent place, wait for.

So, a kind of new functional based method that meets characteristic of Chinese character can be createed, thereby Chinese character pattern can be more ideally described, just become a problem demanding prompt solution.

(goal of the invention)

Aim of the present invention is to address the above problem.The purpose of this invention is to provide a kind of Chinese character contour describing method and realize the hardware restoring technology of this method.This method may further comprise the steps:

A) each Chinese character is splitted into a plurality of strokes.

B) edge of each stroke is divided into several smooth section.Division principle is: straight line separates with curve, and curvature is separated with the little line segment of curvature greatly.

C), described with following array function for each smooth section:

A+BU+CU ²(0≤U≤1)

P(U)= D+EU+FU ²+GU ³(1≤U≤2)

H+IU+JU ²(2≤U≤3)

Wherein, P represents the position vector of each point on the curve, and U is real parameter, and A, B, C, D are coefficient vector, contains the special relationship between three piecewise functions.

D) based on the above method, the curve description information that obtains is placed among the ROM, with the reduction of hardware circuit (as asic chip) realization from the profile information to the lattice information.That is: CPU takes out the profile information of font according to the requirement of software and makes an explanation from ROM, with command mode it is sent into asic chip then, and chip high speed restores the lattice information of required font, and is placed among the SRAM and is taken by CPU.The synoptic diagram of said process is seen Fig. 4.

The purpose of this invention is to provide a kind of Chinese character contour describing method and realize the hardware restoring technology of this method.This method may further comprise the steps:

A) each Chinese character is splitted into a plurality of strokes.

A+BU+CU ²(0≤U≤1)

P(U)= D+EU+FU ²+GU ³(1≤U≤2)

H+IU+JU ²(2≤U≤3)

For making the smooth connection of each section, determine the derivative value at two sections curve tie point places by the following method: promptly get the slope that is linked to be straight line from one section first point wherein to another section end point.

D) with the reduction of hardware circuit (as dedicated IC chip ASIC) realization from the profile information to the lattice information.Reduction work comprises: calculate each point coordinate on the stroke boundary curve by above-mentioned formula, the closed curve of colluding stroke edge is filled this stroke.The relation of this circuit and other circuit as shown in Figure 4, its course of work is: CPU takes out the profile information of font according to the requirement of software and makes an explanation from ROM, with command mode it is sent into asic chip then, chip high speed restores the lattice information of required font, and is placed among the SRAM and is taken by CPU.

Fig. 1 and Fig. 2 represent the synoptic diagram of Chinese character contour describing method of the present invention.

Fig. 3 represents to realize hardware circuit synoptic diagram of the present invention.

Chinese character contour method of the present invention may further comprise the steps:

A) each Chinese character is splitted into a plurality of strokes.

C), construct its edge of following function representation for each smooth section AB:

A+BU+CU ²(0≤U≤1)

P(U)= D+EU+FU ²+GU ³(1≤U≤2)

H+IU+JU ²(2≤U≤3)

Wherein, P represents the position vector of each point on the curve, and component is X, Y; U is real parameter, A, and B ..., J is the undetermined coefficient vector, component is Ax, Ay; Bx, By; ...; Jx, Jy.

For the Y component,, equation is arranged referring to Fig. 1:

Ay+ByU+CyU ²(0≤U≤1)

Y(U)= Dy+EyU+FyU ²+GyU ³(1≤U≤2)

Hy+IyU+JyU ²(2≤U≤3)

Note: Y(0)=Y0, Y(1)=Y1, Y(2)=Y2, Y(3)=Y3,

Y is Dy1 the 1st left derivative to U, and Y is Dy2 the 1st right-hand derivative to U, and Y is Dy3 the 2nd left derivative to U, and Y is Dy4 the 2nd right-hand derivative to U, then can solve behind the substitution equation:

Ay＝Y0

By＝-4Y1+5Y2-4Dy2-2Dy3

Cy＝-3Y2+4Y3-6Dy4

Dy＝-2Y0+2Y1-Dy1

Ey＝12Y1-12Y2+8Dy2+5Dy3

Fy＝4Y2-4Y3+5Dy4

Gy＝Y0-Y1+Dy1

Hy＝-9Y1+9Y2-5Dy2-4Dy3

Iy＝-Y2+Y3-Dy4

Jy＝2Y1-2Y2+Dy2+Dy3

For the X component,, equation is arranged referring to Fig. 2:

Ax+BxU+CxU ²(0≤U≤1)

X(U)= Dx+ExU+FxU ²+GxU ³(1≤U≤2)

Hx+IxU+JxU ²(2≤U≤3)

Note: X(0)=X0, X(1)=X1, X(2)=X2, X(3)=X3,

X is Dx1 the 1st left derivative to U, and X is Dx2 the 1st right-hand derivative to U, and X is Dx3 the 2nd left derivative to U, and X is Dx4 the 2nd right-hand derivative to U, then can solve behind the substitution equation:

Ax＝X0

Bx＝-4X1+5X2-4Dx2-2Dx3

Cx＝-3X2+4X3-6Dx4

Dx＝-2X0+2X1-Dx1

Ex＝12X1-12X2+8Dx2+5Dx3

Fx＝4X2-4X3+5Dx4

Gx＝X0-X1+Dx1

Hx＝-9X1+9X2-5Dx2-4Dx3

Ix＝-X2+X3-Dx4

Jx＝2X1-2X2+Dx2+Dx3

So just obtained describing the parameter equation that this smooth curve changes.Make parameter U in [0,3] interval, change continuously, can obtain the coordinate (X(U) of each point on this curve, Y(U)).

Usually, the edge of a Chinese character stroke is joined by many smooth curves and forms.Thereby the phase contact of how handling each curve when describing the overall profile of stroke under the condition in discrete calculation guarantees the smooth of stroke edge, then is the another gordian technique in the Chinese character curved profile word technology.Referring to Fig. 3, AB, BC, three curves of CD join.Because the discretize and the limit, the derivative that B is ordered can't accurately be obtained in computation process.But for guaranteeing that the smooth of phase contact must obtain the derivative value that B is ordered again.In order to solve this contradiction, this patent author has found a kind of highly effective approximation method through a large amount of practices, i.e. the derivative value of order as B with the slope of straight line AC, the derivative value (see figure 3) of using the slope of straight line BD to order as C.This method has obtained good effect in actual applications.

D) finish the reduction of font with hardware circuit (as dedicated IC chip ASIC).Reduction work comprises: calculate each point coordinate on the stroke boundary curve by above-mentioned formula, the closed curve of colluding stroke edge is filled this stroke.The relation of this circuit and other circuit as shown in Figure 4.Character contour information is stored in the read only memory ROM (as MASKROM), CPU takes out the profile information of font according to the requirement of software and makes an explanation from ROM, with command mode it is sent into asic chip then, chip high speed restores the lattice information of required font, and is placed in the random access memory (as SRAM) and is taken by CPU.

Describe Chinese character with the method that this patent provides, can guarantee very high Information Compression ratio, be convenient to realize full integer arithmetic.The more important thing is that this method has extremely strong Chinese character descriptive power, no matter which kind of font, which kind of font size, reduction effect is all very perfect.The dynamic property of this function is fine, is convenient to the structure of font.In a word, this method make that profile Chinese character description technique has entered big or small unification, font is vivid, Information Compression than high, reduce frontier efficiently.Make the curved profile word font product of having made Song, imitation Song-Dynasty-style typeface, pattern in this way, having deceived four kinds of fonts, can be widely used in many application scenarios such as computing machine, printer.

Claims

1, a kind of descriptor is handled with the mixed-spline functional based method of Chinese character contour and is realized the hardware technology of this method, and this method comprises the steps:

B) edge of each stroke is divided into several smooth section,

A+BU+CU ²(0≤U≤1)

P(U)= D+EU+FU ²+GU ³(1≤U≤2)

H+IU+JU ²(2≤U≤2)

2, according to the method for claim 1, it is characterized in that: the derivative value of determining two sections curve tie point places by the following method: promptly get the slope that is linked to be straight line from one section first point wherein to another section end point.

3, according to the method for claim 1, it is characterized in that: with the reduction of hardware circuit (as dedicated IC chip ASIC) realization from the profile information to the lattice information.Reduction work comprises: calculate each point coordinate on the stroke boundary curve by above-mentioned formula, the closed curve of colluding stroke edge is filled this stroke.