JPH0749222B2 - Filling method inside closed curve - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to a method of filling a closed curve suitable for use in a printing system or the like that prints out high-quality characters. “Prior Art” With the development of laser printers in recent years, a system capable of printing high-quality characters in various character fonts such as Mincho and Gothic is being developed. In such a printing system, it is required that not only characters in various character fonts can be printed but also the character size can be set arbitrarily. However, in this type of conventional system, it is common to have a character font with pixel data, and therefore simple size changes such as 2x and 1 / 2x are possible, but 3.5x, 5x, It was impossible to perform enlargement / reduction at an arbitrary magnification such as 1 / 7x without impairing print quality. On the other hand, as a method of making it possible to print characters of various character fonts in an arbitrary size, a method of using a character font with an outline (contour line) vector is known. When enlarging or reducing a character by this method, vector data is previously enlarged or reduced by calculation, the vector data obtained by this calculation is converted into contour line pixel data, and then the inside of the contour line is filled. Character. According to this method, the print quality will not be impaired by any enlargement or reduction. Further, the present invention relates to a filling method suitable for use especially for filling the inside of the outline of a character described above. Next, a conventionally known filling method will be described. (1) Parity check method In FIG. 11, reference numeral 1 is an image memory having a storage capacity equal to the number of pixels of one page of printing paper, and 2 is an outline of an image written by data "1" in the image memory 1. It is a line. When filling the inside of the contour line 2, the parity check method performs horizontal scanning in order from the maximum value or the minimum value of the contour line written in the image memory 1. When the contour line (data “1”) is detected,
The data “1” is sequentially written, the writing is stopped when the contour line is detected next, and when the contour line is detected next, the data “1” is written again and this process is repeated. By such processing, for example, in scanning at the position of the broken line L1 in the figure, "1" is written (filling is performed) in the ranges H1 and H2. (2) Tracking method In FIG. 12, reference numeral 3 is a contour line written in the image memory, and SE is an arbitrary point in the contour line 3 (referred to as a seed).
Is. In this tracking method, first, the contour line 3 is detected by scanning the image memory in the direction of the arrow Y1 from the seed SE. Next, for example, the data "2" is written in the storage position of the image memory corresponding to the pixel P1 on the inner side of the contour line 3. Below, along the contour line 3, the pixels P2, P inside the contour line 3
Write "2" to the memory locations corresponding to 3 ... Then, data “2” for the entire circumference along the contour line 3
When the writing of data is completed, the pixels between which the data “2” has been written are filled in, that is, in this case, the data “2” is written. During this filling, for example, if another contour line 4 is detected (see scanning of arrow Y2), after writing data "2" around the contour line 4 (in this case, outside), the data "2" is again written. Fill between 2 "and" 2 ". (3) Segment Method In FIG. 13, reference numeral 5 is a contour line drawn in the image memory, and SE is a seed. In this segment method, first, the seed SE is filled in the direction of the arrow Y3. Then, when the pixel Pa of the contour line 5 is detected, the address of the contour line pixel on the contour line 5 is stored in the temporary storage memory as the stack address ST1, and then from the contour line pixel Pb below the pixel Pa in the arrow Y4 direction. Fill to. Then, when the contour pixel Pc is detected, next, the pixel Pd below it is filled in the direction of the arrow Y5, and thereafter, this operation is repeated to fill the area E1 shown in the figure.
In the filling process, continuity between contour line pixels, that is, continuity of pixels Pa, Pb, Pe ... and continuity of pixels Pc, Pd. Then, when the above continuity is broken, that is, when the pixel Pk is detected, the address of the next pixel is stored in the memory as the stack address ST2, and then the pixel Pl is filled again. Then, when the filling of the area E2 shown in the drawing is completed, the stack address ST2 is read from the memory, and the pixel indicated by the address is filled to fill the area E3. Next, the area E4 is filled by performing painting upward from the pixel indicated by the stack address ST1. The above is the conventionally known filling method. [Problems to be Solved by the Invention] However, each of the above-described filling methods has various drawbacks, and therefore cannot be practically used for filling characters. That is, first, (1) the parity check method has the following drawbacks. In FIG. 14, pixels P1 and P2 are the vertices (maximum points) on the contour line 6 and both are horizontal lines.
Let it be a point on L2. In this case, if the filling is performed while scanning the line L2, the range Ha shown in the figure will be filled. To prevent this, it is necessary to detect that the pixels P1 and P2 are vertices. However, in order to detect this vertex, it is necessary to read out each pixel data of the immediately preceding line and compare it with each pixel data of the line L2, but this process requires a lot of time. Even if such comparison processing is performed, the vertices shown in FIG.
Detection of P3 is not possible. Further, in FIG. 16, when the line L3 is scanned and filled, the range Hb is filled, but the range Hc is not filled. Further, in the case of FIG. 17, the area Ea, which should not be filled originally, is filled. The shapes shown in FIGS. 15 to 17 do not appear in the original character font, of course. However, when characters are reduced, such shapes often appear. Therefore, when filling characters,
It is necessary to be able to fill a figure in which such closed curves and lines are mixed. Next, both (2) tracking method and (3) segment method,
Seeds must be set in advance in all areas to be filled, and if it is an alphabet, and if it is divided into a large number of closed curves, such as a Kanji font, then all of the closed curves will be filled. Setting the seed is extremely troublesome. Further, even if the seed is set in the original character font in advance, a closed curve without seed is generated due to the reduction, and in this case, the filling cannot be performed. Furthermore, these methods take a long time for the filling process, so that at most 10 or more characters can be filled in one second, and the filling speed of 2000 characters / second required for the laser printer is extremely low. It cannot be achieved. As described above, none of the conventional filling methods can be applied to the filling of character (especially Kanji) fonts, and there is no filling method applicable to the filling of character fonts. The present invention has been made in view of the above-mentioned circumstances, and a filling method within a closed curve that can be filled at an extremely high speed and without error can be applied to a filled font. It is intended to be provided. "Means for Solving the Problem" The present invention converts a vector data representing a contour line into pixel data, writes the pixel data in the image memory, and fills the inside of the image memory surrounded by the pixel data with the pixel data. In the filling method, the vector data is converted into pixel data by DDA processing, and at the same time, the attribute data corresponding to the attribute of the vector is the inclination of the vector obtained from the DDA processing, and the direction and the attribute data of the vector. Is logically operated on the basis of the attribute data already written to the memory location to be written, and the attribute data obtained thereby is written to the image memory together with the pixel data, and then the pixel data and the attribute data are written. Image memory and scan the image memory It is characterized in that the attribute data in the memory is detected, and the filling position is determined based on the value of the detected attribute data. [Operation] According to the present invention, when the vector data is converted into the pixel data and is written in the image memory, the attribute data of the pixel is written in the image memory. And
In the filling process, the vector data is converted into pixel data by the DDA process. At the same time, the attribute data corresponding to the attribute of the vector is logically calculated based on the inclination of the vector obtained from the DDA process, the direction of the vector, and the attribute data already written in the memory location where the attribute data should be written. It Then, the attribute data thus obtained is written in the image memory together with the pixel data, and then the image memory in which the pixel data and the attribute data are written is scanned to detect the attribute data in the image memory. The filling position is determined based on the detected value of the attribute data. [Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a printing system to which a filling method according to an embodiment of the present invention is applied. First, the overall configuration will be described.

【overall structure】

In FIG. 1, 1 is a CPU (central processing unit), 2 is a CPU1
ROM storing the program of 3 and RA for data storage
M and 4 are character font memories. Each character (kanji, kana, alphabet, etc.) is stored in this character font memory.
The contour line is stored as vector data. Specifically, for example, in the case of the letter “G” shown in FIG. 2, it is stored by the coordinate data (P _x , P _y ) of the points P _{0 to} P ₂₄ shown in the figure. Reference numeral 5 is a floppy disk device, on which a floppy disk storing a text to be printed is set. Reference numeral 6 is an operation unit. In the above configuration, when the floppy disk is set in the floppy disk device 5, various instructions such as designation of the character size are given by the operation unit 6 and then the print start instruction is given, the CPU 1 receives this instruction, and first, Read one page of character data from the floppy disk and write it to RAM3. Next, the character font corresponding to each character data written in the RAM 3 is sequentially read from the character font memory 4, and is output to the coordinate conversion processor 8 together with the layout information about the curve formula and the character print position used when performing the curve interpolation. To do. The coordinate conversion processor 8 forms a smooth curve by curve-interpolating the contour vector. Specifically, the second
Taking the vector P ₃ → P ₄ in the figure as an example, this vector is further divided into small line segments, and the coordinate data of each point P _3-1 , P _3-2 ...
It is calculated based on the curve formula output from 1. Next, the character font is enlarged / reduced according to the size of the character designated by the operation unit 6, and the enlarged / reduced character font (specifically, coordinate data) is output to the painting processor 9. The fill processor 9 first detects the coordinate conversion processor 8
Converts the vector represented by the coordinate data supplied from the to a pixel column. Specifically, for example, from the coordinate data (X ₀ , Y ₀ ) and (X _n , Y _n ) representing the start point and the end point of the vector V shown in FIG. 3, the pixels P ₁ , P ₂ , P ₃ ... P _n-1
Calculate the coordinate data of. The coordinate data of the pixels P ₀ and P _n are (X ₀ , Y ₀ ) and (X _n , Y _n ), respectively. Most of this processing is realized by hardware called DDA (Digital Difference Analyzer). And above
The coordinate data for interpolating between two points obtained by the DDA process is converted into the address of the page memory 10 based on the layout information output from the CPU 1. Here, the page memory 10 is composed of three memories (DRAM), each memory has the same number of bits as the total number of pixels of one page of print paper, and all three can be written / read at the same address. Done. That is, attribute data of 3 bits per accelerator can be written in the page memory 10. Further, the painting processor 9 writes the attribute data of the pixel in the storage position of the page memory 10 indicated by the address of each pixel. The attribute data will be described later. Next, when one page of pixel data (attribute data) is written in the page memory 10, a filling process for filling the inside of each character is performed. Then, when the filling process is completed, the data in the page memory 10 is read and output to the laser printer 11. As a result, the laser printer 11 prints.

[Details of Filling Processor 9] Next, details of the processing performed in the filling processor 9 will be described. (1) DDA processing This DDA processing is performed in the following process (see FIG. 3). The following calculation is performed to obtain the respective differences ΔX and ΔY of the X and Y coordinates. ΔX = X _n −X ₀ …… (1) ΔY = Y _n −Y ₀ …… (2) The difference of the coordinates is obtained by this calculation, and ΔX,
The direction of the vector V (X direction and Y direction) can be detected from the sign of ΔY. That is, △ X, △ Y
If both are positive, the direction of the vector V is positive in both the X and Y directions. If both ΔX and ΔY are negative, the direction of the vector V is X.
Direction, negative Y direction, if ΔX is positive, ΔY is negative, vector V direction is positive, X direction is positive, Y direction is negative, ΔX is negative, ΔY is positive, vector V direction Is negative in the X direction and positive in the Y direction. The difference D between the absolute values of the above differences ΔX and ΔY is calculated. D = | ΔX | − | ΔY | (3) From the sign of D obtained by this operation, it is determined in the vector V which direction, X or Y, is the major axis and which direction is the minor axis. Can be detected. Note that, hereinafter, when the X direction is the long axis (D> 0), it is called the X major, and when the Y direction is the long axis (D <0), it is called the Y major. The coordinate data of the pixels P _{1 to} P _n-1 are obtained. -(1) When the vector V is the X major Yi = (ΔY / ΔX) (Xi−X ₀ ) + Y ₀ (4) In the formula, data (X ₀ +1), which is stepwise incremented to Xi,
(X ₀ +2), ... (X ₀ + n-1) are sequentially substituted and data
Y ₁ , Y ₂ ... Y _n-1 is calculated. The resulting coordinate data {(X ₀ +1), Y ₁ }, {(X ₀ +2), Y ₂ } ... {(X ₀ +
n-1), Y _n-1 } is the coordinate data of the pixels P _{1 to} P _n-1 to be obtained. -(2) When the vector V is the Y major Xi = (ΔX / ΔY) (Yi−Y ₀ ) + X ₀ (5) In the formula, data (Y ₀ +1), which is stepwise incremented to Yi,
By sequentially substituting (Y ₀ +2), ... (Y ₀ + n-1), the data X ₁ , X ₂ ... X _n-1 wo are calculated, and the pixels P _{1 to} P ₁
Obtain each coordinate data (Xi, Yi) of _n-1 . (2) Address calculation of page memory 10 Coordinate data indicating the printing position of each character on the paper, in other words, the writing position of each character in the page memory 10, is output from the coordinate conversion processor 8. The coordinate data is the base point P ₀₀ of the coordinates of the character shown in Figure 2. Now, assuming that this coordinate data is (P _x , P _y ), the page memory 10 of each pixel Pi (Xi, Yi) forming the outline of the character in FIG.
The position (address) at is (P _x + Xi, P _y + Yi). (3) Writing of Attribute Data to Page Memory 10 In this printing system, the attribute data (3 bits) of the pixel is written to each storage position of the page memory 10 corresponding to each pixel forming the contour line. . Here, the attribute data is (a) the inclination of the vector to which the pixel belongs, that is, whether the vector is the X major or the Y major, or (b) the X direction and the Y of the vector to which the pixel belongs.
Direction (c) Attribute data already written in the storage position of the page memory 10 corresponding to the pixel It is data determined based on the above three elements. The attribute data will be specifically described below with reference to FIG. FIG. 4 is an attribute data table. In this table, the column labeled "old" indicates the attribute data that has already been written, and the column labeled "new" indicates the attribute data that is about to be written. Ordinary outline pixel attribute data Vector V (character outline vector) shown in FIG. 3 is Y
In the case of the major (| X | <| Y |), the attribute data of the pixels P _{0 to} P _n are all “1”, and the X major (| X |> | Y |)
If it is, all are “2”. Then, when the data is not written in the storage position corresponding to each of the pixels P _{0 to} P _n of the page memory 10 (in the case of “0”), the above-mentioned attribute data “1” or “2” is the page memory. Ten
Is written as is. The attribute data of the connecting point pixel of each of the two vectors having different directions is obtained from the two vectors V1 and V2 shown in FIGS.
When they are connected in the order of V1 → V2, the end point of the vector V1 and the start point of the vector V2 are the same pixel. In this case, the attribute data of the connection point pixel Ps is as follows. (I) As shown in FIGS. 5 (a) and 5 (b), the vector V1
→ In V2, if the sign in the Y direction changes, it becomes “3”. Below, this case is referred to as VerEdge (Vertical E
dge). (Ii) As shown in FIGS. 5 (c) and 5 (d), when the sign in the X direction changes, the value is "4". Hereinafter, this case is referred to as Hor Edge (Horizontal Edge). (Iii) As shown in FIGS. 5 (e) and 5 (f), the X direction,
The case where there is no change in the Y direction is the same as the case where there is only the vector V2 (when there is no connection point). That is, in the case of FIG. 5 (e) (X major), it becomes "2", and in the case of (f) (Y major), it becomes "1". In addition, FIG.
As shown in (H), the X or Y direction of vector V2 is 0.
The same applies when (Iv) When the X direction or the Y direction changes from “0” to positive or negative like the vectors V1 and V2 shown in FIGS. 5 (i) and (nu), the vector V0 before the vector V1 is changed. It depends on the direction. That is, as shown in FIG. 5 (i), when there is no direction change in the vector V0 → V2, the above (ii)
i), and if there is a direction change in the vector V0 → V2 as shown in FIG.
Or (ii). Double or triple attribute data when attribute data has already been written to the storage location of the page memory 10. Attribute data at the time of writing Each character font in the character font memory 4 is of course designed so that outlines do not overlap. . Therefore, if the character size is the specified size or expansion, the page memory
There is no double writing within 10. However, when the character font is reduced, outlines often overlap, and therefore double writing often occurs, and sometimes triple writing, quadruple writing ... Occur. At the time of this double, triple ... writing, the attribute data to be written (attribute data determined by or above; see FIG. 4, “New” column) and already written attribute data (see FIG. 4, “old”). ) Column), the attribute data to be newly written is determined based on the attribute data table of FIG. For example, if the attribute data that has already been written is "2" and the attribute data that is about to be written is "2", then "6" is written. For example, the already written attribute data is "4", and If the attribute data to be written is "1", "5" is written. In the case of writing the attribute data at the starting point of the vector, the attribute data table is not applied and the above-mentioned rule is applied. The above is the details of the attribute data writing process. In an actual device, each of the above processes is performed on a pixel-by-pixel basis. That is, for example, in the processing of the vector V in FIG. 3, first, the attribute data of the pixel Pi (attribute data based on the inclination and direction of the vector V) is obtained, and then,
The address of the page memory 10 where the attribute data is written is obtained by the DDA process. Then, the address is output to the page memory 10. As a result, the attribute data (or data “0”) already written is read from the page memory 10. Next, a logical operation (logical operation based on the table of FIG. 4) is performed between the read attribute data and the attribute data to be written, and the result of this operation is written to the above address of the page memory 10. In this case, the read / write processing described above is performed in the well-known read modify write mode. Then, the above processing is sequentially performed for each pixel Pi forming the vector V. (4) Filling process When the writing of the attribute data to the page memory 10 is completed,
Next, this filling processing is performed. By this filling processing, the inside of the outline of the character is filled. Specifically, data (for example, “1”) is written in the storage position of the page memory 10 corresponding to each pixel inside the contour line. This filling process is basically the same as the filling process by the parity check method, and each storage position of the page memory 10 shown in FIG. 1 is sequentially scanned from the top row from left to right to obtain a contour line, that is, an attribute. When data is detected, the parity is changed based on the attribute data. Here, the parity is "1" → "0" → every time there is a change instruction.
It is data that alternates from “1” → ..., and is 1-bit data created by a trigger flip-flop. Then, when the scan passes through the contour line and reaches the area of the data “0”, if the parity at that time is “1”, the area is filled, and if the parity is “0”, the filling is not performed.
The above is the outline of the filling process. Next, the relationship between attribute data and parity will be described. Sixth
The figure shows the parity change table.
"t" indicates the left storage position of the two storage positions arranged side by side, and "Right" indicates the right storage position. Further, “1” indicates a parity change instruction, and the blank column indicates that the parity is not changed. Hereinafter, the filling process based on this table will be described with an example. FIG. 7A shows the contour line vector and the scanning line Sc,
(B) shows each storage position on the scanning line Sc. First,
Before the scanning of the scanning line Sc is started, the parity is reset to “0”. Next, when scanning (data reading) of storage positions K1 to K4 is performed and then data reading in storage position K5 is performed, attribute data "2" is read. In this case, the change is “0” → “2”, the parity change table of FIG. 6 is blank (see # 1), and the parity does not change. Next, the attribute data "2" in the storage location K6 is read. In this case, the change is “2” → “2”, the parity change table is blank (see # 2), and the parity does not change. Next, the attribute data “0” at the storage location K7 is read. In this case, "2" →
This is a change of "0", and the parity change table is "1".
(See # 3). Therefore, a parity change instruction is generated and the parity becomes "1". Further, in this case, since the data of the storage position is "0", it is determined whether or not the filling is performed. In this case, since the parity is "1", the data "1" is written in the storage position K7. Below, memory locations K8, K9, K10
The data in is read out sequentially, and since each data is "0", it is rewritten to "1" (that is, painting is performed). Next, the data in the storage locations K11, K12, K13 are read, the contour line is detected again, and the processing based on the parity change table is performed. And storage location K1
In the data processing of 3, the parity change instruction is generated again and the parity becomes “0”. As a result, subsequent memory locations
K13, K14 ... are not filled. In addition, the outline is rarely composed of 1 pixel,
As shown in FIG. 7 described above, it is often composed of a plurality of pixels. By the way, there is a case where the filling cannot be properly performed only by the processing based on the parity change table described above. Therefore, in this embodiment, the following exceptions are provided. (Exception 1) If the contour line includes VerEdge “3”, the parity change instruction is not issued. (Exception 2) In the case of a contour line including HorEdge “4”, a parity change instruction is given. (Exception 3) In the case of a contour line that does not include VerEdge “3” and HorEdge “4” and that includes attribute data “6”, the parity change instruction is not performed. (Exception 4) In the case of a contour line that includes an even number of VerEdge “3” and also includes attribute data “6”, the parity change instruction is not performed. (Exception 5) In the case of an outline including an odd number of VerEdge “3” and including attribute data “6”, a parity change instruction is given. (Exception 6) In the case of a contour line including an odd number of HorEdge “4” and an attribute data “6”, the parity change instruction is issued when the attribute data “6” is an even number, and the parity change is performed when the number is an odd number. Do not give instructions. Then, the parity is changed based on the parity change table shown in FIG. 6 and the exception rule described above,
If the filling is performed based on the obtained parity, the inside of the contour line of any shape can be filled without error. Next, an example of the actual parity detection process will be described. For each row of the page memory 10, first, for example, eight pieces of attribute data are sequentially read from the left end, and “0” → “1 to 7”.
And the change point of "1 to 7" → "0" are detected to detect the contour line. Next, for each attribute data included in the contour line, the number of times of each change of “1” → “0” “1” → “1” “1” → “5” “2” → “0” is detected. (Referred to as first detection)
Presence / absence of data “3”, “4”, “6” and, in the case of “present”, it is detected whether the number is odd or even (referred to as second detection). Next, from the above second detection result,
It is checked whether or not (Exception 1) to (Exception 6) are satisfied, and the parity is determined from this result and the result of the first detection. It goes without saying that the first and second detections and the determination of the parity can be performed by simple hardware. Next, an example of filling in a special case will be described. When the scanning line Sc shown in FIG. 8 passes through the vertical vertex Pd of the contour line In this case, the attribute data is “3” at the storage position corresponding to the vertex Pd as shown in FIG. Therefore,
(Exception 1) is applied, and there is no change in parity on the left and right of this vertex Pd. As a result, if the left side of the vertex Pd is filled, the right side is also filled, and if the left side of the vertex Pd is not filled, the right side is not filled. When Horizontal Lines Overlap As shown in FIG. 9A, when the character font outline vectors V2 and V5 in the character font memory 4 are very close to each other, when the character font is reduced. , Vectors V2 and V5 overlap. In this case, the writing of the attribute data in the page memory 10 is performed as follows. That is, first, the vector V1 is converted into a pixel, and the pixel is stored in the storage position corresponding to each pixel in FIG.
The attribute data “2”, “2”, ... shown in are written in sequence, and then the attribute data “2”, corresponding to the vector V2,
"2" ... Are sequentially written, and then attribute data "3", "1", "1" ... Are written corresponding to the vector V3. Next, the attribute data “1” corresponding to the vector V4,
"1" and "1" are written, then attribute data "2"
Is about to be written to the memory location Ka, but at this time, the attribute data “2” has already been written to the memory location Ka,
Therefore, the attribute data "6" is written in the storage location Ka according to the attribute data table of FIG. Thereafter, the attribute data corresponding to the vectors V5 and V6 are similarly written. Next, during the filling process, especially the scanning lines shown in the figure
At the time of scanning Sc, the attribute data of "2,6,6,6,3,2,3" as the contour line is detected. In this case, the definition of (Exception 4) applies, so there is no parity change in the contour. Note that according to the conventional parity check method, the parity changes at the above contour line, and therefore
As described with reference to FIG. 16, if the left side of the contour line is filled, the right side is not filled. In other words, it becomes an incorrect fill. When a plurality of vertical lines overlap As shown in Fig. 10 (a), when the contour line before reduction has a comb shape and no reduction is performed, the page memory 10 corresponding to the scanning line Sc As shown in the figure, 6 pieces of attribute data "1" are written in the storage positions corresponding to the 6 vertical lines shown in the figure. On the other hand, as shown in FIG. 10 (b), the six vertical lines are reduced by the reduction.
When it overlaps with the book, the next attribute data is written in the storage position Kb corresponding to the intersection of the scanning line Sc1 and the vertical line. First, when the first vertical line is converted to a pixel and the attribute data of each pixel is written to the page memory 10,
The attribute data “1” is written in the storage position Kb. next,
When the second vertical line is converted into pixels and written, the attribute data “1” is about to be written. At this time, however, since the attribute data “1” has already been written in the storage position Kb, According to the attribute data table of FIG. 4, the attribute data “5” is written in the storage position Kb. Next, when the third vertical line is converted into pixels and written, the attribute data “1” is about to be written, but at this time, the attribute data “5” has already been written in the storage position Kb. Therefore, the attribute data “1” is written in the storage position Kb according to the attribute data table of FIG. Thereafter, similar processing is repeated, and finally the attribute data “5” is written in the storage position Kb. Next, at the time of filling, the storage position Kb is good when scanning the scanning line Sc1, and before and after that ... “0” → “5” →
Attribute data of "0" ... is sequentially detected, but
As for the change of "0" → "5" and the change of "5" → "0", the parity change instruction is not issued by referring to the parity change table of FIG. Therefore, Fig. 10 (b)
In the case of the pattern, the filling is performed on both the left side and the right side of the storage position Kb. The vertical line of the pattern before reduction is the 10th
In the case of an odd number as shown in FIG. 3C, the attribute data “1” is finally written in the storage position Kb. In this case, in the filling process, the parity change instruction is not issued when the change of “0” → “1” is detected, but the parity change instruction is issued when the change of “1” → “0” is detected. If the left side of the is filled, the right side is not filled. The above is the details of the embodiment of the present invention. According to this embodiment, at the time of the DDA processing, the attribute data of the pixels are simultaneously obtained and written in the page memory 10. In this attribute data writing process, vector inclination determination (| X | − | Y |)
Originally performed in DDA processing. Therefore,
The processes particularly required for writing the attribute data are the direction determination and the logical operation process of FIG. However, the direction determination is a process performed only at the start point and the end point of the vector, and is merely a subtraction process, and can be processed in an extremely short time. Further, it goes without saying that the logical operation processing of FIG. 4 can be performed in an extremely short time if it is performed by hardware. Therefore, the attribute data writing process is almost the same as the time for the conventional DDA process. On the other hand, parity detection at the time of filling can also be performed in an extremely short time if performed by hardware. That is, according to this embodiment, it is possible to fill at an extremely high speed, and when the character font is filled, it is possible to fill at a speed of 2000 characters / sec. [Advantages of the Invention] As described above, according to the present invention, all patterns including contour line intersections, overlaps, sharp bends, and the like, which cannot be accurately filled by the conventional method, can be obtained. Filling can be performed extremely quickly and accurately. As a result, it is particularly suitable for filling character fonts in a printing system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a printing system according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of a character font, and FIG. 3 is a vector constituting a character font and a pixel string corresponding to the vector. FIG. 4, FIG. 4 is a diagram showing an attribute data table used when writing attribute data, FIG. 5 is a diagram for explaining attribute data of pixels at connection points of two vectors, and FIG. 6 is painting. A diagram showing a parity change table used in processing,
FIG. 7 to FIG. 10 are diagrams for explaining specific examples of the filling process, and FIGS. 11 to 17 are diagrams for explaining the conventional filling method and its problems. 1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... Character font memory, 9 ... Fill processor, 10 ... Page memory.

Claims (1)

[Claims] 1. A method of filling a closed curve within a closed curve, wherein vector data representing a contour line is converted into pixel data, written into an image memory, and the inside of the image memory surrounded by the pixel data is filled with the pixel data. Is converted to pixel data by DDA processing, and at the same time, the attribute data corresponding to the attribute of the vector is already written to the inclination of the vector obtained from the DDA processing, the direction of the vector, and the memory location where the attribute data should be written. Logical operation is performed based on the attribute data stored therein, the attribute data obtained thereby is written in the image memory together with the pixel data, and then the image memory in which the pixel data and the attribute data are written is scanned to obtain the attribute data. Detects the attribute data in the image memory The method fills the closed curve, characterized by determining a position filled based on the value of the detected attribute data.