JP2852859B2 - Line break processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a line break in a line drawing by correcting line drawing data representing the line drawing.

[0002]

2. Description of the Related Art In a plate making process for preparing a printing plate for color printing, an underlaying board which is an original of characters and line drawings is prepared. The underlaying board is one in which typesetting characters and drafted ruled lines are arranged with the same size and quality as the final printed matter. Instructions for the subsequent steps are also written on the underlaying sheet, and also serve as instructions for the plate making process.

[0003] In many cases, a color-imparting process is performed in a plate-making process to fill a part of an image with a desired uniform color. 2. Description of the Related Art In recent image processing systems, there is a system that automatically performs a coloring process which has been performed manually until now. In such a system, the binary image data of the composition image is read by a scanner, and the image processing device performs a coloring process by painting a desired area separated by a line in the composition image with a desired color.

[0004] When such a coloring process is performed, there is a case where a line drawing that should form a closed region in the underlay image has "line breakage". The cause of the “line break” is a line break existing on the original image (underlaying board), a reading error when reading by the image reading device, and the like. Conventionally, the operator has directly searched for the position of a line break from the composition image displayed on the CRT, and has corrected the composition image so as to connect the broken lines.

[0005]

However, since the width of a line break is often about one pixel to several pixels, it is difficult for an operator to find the line break on a CRT, and there are many line breaks. In such a case, there is a problem that it takes a considerable processing time to find and correct all of them.

As a method for detecting and connecting a broken line in an image, for example, Japanese Patent Laid-Open No.
No. 2,393,387.

[0007]

However, the above-described method has a problem that it is difficult to detect a broken line where a gap is opened in a direction parallel to the scanning line.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem in the prior art, and provides a method for easily detecting a broken line regardless of the direction of a broken line gap. With the goal.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for processing a broken line according to the present invention is described as follows.
(A) processing line breaks in the line drawing by processing line drawing data representing a first line drawing in which a line of a second color is drawn on a background of the color of (a). (B) forming an additional area around the image area by widening the image area of the second color by a predetermined width in one line drawing, thereby generating a second line drawing;
Generating a third line drawing by thickening the image area of the first color included in the second line drawing by the predetermined width; and (C) generating a third line drawing remaining in the third line drawing. Determining the number of color changes around the additional area;
(D) detecting the additional area as a line break candidate area when the number of color changes is four or more.

By executing the thickening process for the second color and the thickening process for the first color with a predetermined width,
The additional region remains in a minute portion such as a broken line. Since the number of color changes around the additional region remaining at the line break becomes four or more, the line break candidate region that is a candidate for a line break is obtained by examining the number of color changes around each additional region. Can be detected.

The above method may further comprise the step of: (E) connecting a line break existing in the first line drawing by filling the line break candidate area with the second color. Good. In this case, the wire break can be easily connected.

[0012]

FIG. 1 is a block diagram showing the configuration of a line drawing processing apparatus 20 for processing line drawing data according to an embodiment of the present invention. The line drawing processing device 20 includes the following components.

CPU 22: control of each part of the line drawing processing device;
In addition, various processes related to line drawing data (such as pinhole erasure, display image data creation, detection of a line break candidate region, repair of a line break, and filling) are performed. CPU 22
And components described below are interconnected via a bus 24.

ROM 26: stores a processing program executed by the CPU 22.

RAM 28: A memory for storing various parameters and temporary data used for image processing of line drawings.

Line drawing memory 32: A memory for storing line drawing data, and a color palette is also stored here.
The line drawing memory 32 has a plurality of memory planes capable of storing line drawing data for one page. Since some line drawing processes need to store source line drawing data (line drawing data before processing) and destination line drawing data (line drawing data after processing), at least two memory planes are prepared. I have. Such line drawing processing is generally called “source / destination processing”. For example, the thickening process and the thinning process described later are both source / destination processes.

Keyboard I / O interface 34:
An interface for receiving inputs from the keyboard 36 and the mouse 38.

Display controller 42: converts line drawing data to color CR
Interface used when displaying line drawing by transferring to T44. When displaying a line drawing on the CRT 44, the CPU
After the line drawing data is thinned out, the bit map data is developed by bit map development and the bit map data is transferred to the display control unit.

Image data input / output interface 46:
An interface used when receiving line drawing data supplied from the flatbed scanner 60 and transferring the line drawing data to the recording scanner 50.

The flat scanner 60 is a scanner that reads binary line drawing data from a black and white line drawing such as a block copy. The read line drawing data is supplied from the flat scanner 60 to the line drawing processor 20 in the form of run-length data, and is stored in the line drawing memory 32.

The recording scanner 50 is a scanner that records four color separation images of YMCK on a photosensitive film from line drawing data representing a colored line drawing.

FIG. 2 is a flowchart showing the procedure of the line drawing process. In step S1, line drawing data is read using the flat scanner 60. FIG. 3A is a plan view showing a line drawing represented by the read line drawing data. This line drawing consists of black regions R1, PH1,
It is an image in which PH2 is arranged. A color number # 0 indicating white is assigned to the background area, and the area R1, PH
1, PH2 is assigned a color number # 1 indicating black. The regions PH1 and PH2 are pinholes.
The region R1 includes a line break CT1 that can be visually observed.

FIG. 4 is a conceptual diagram showing the structure of line drawing data representing the line drawing of FIG. As shown in FIG. 4A, the line drawing data is composed of a header, a color palette, and run-length data. The header includes the file name of the line drawing data, the size of the line drawing, the resolution, and the like. In the color palette shown in FIG. 4B, halftone dot area ratios (halftone%) of four color planes YMCK are registered corresponding to respective color numbers. The color palette shown in FIG.
Although only two color numbers # 0 and # 1 are registered, when a new color number is assigned to each part of the line drawing, the halftone% of each color plate corresponding to the color number is registered in the color palette.

The run length data shown in FIG.
One unit of data formed for each run of the line drawing
(Referred to as “unit run-length data”). The unit run length data includes a color number and a run length of each run. Note that FIG. 4C corresponds to FIG.
3 shows unit run length data corresponding to the scanning line SL shown in FIG. Symbol "X" described in the column of color number
Indicates invalid data. The unit run length data having a run length of 0 is data indicating the end of a scanning line. Such line drawing data is stored in the line drawing memory 32.

In step S2 of FIG.
At 0, pinhole erasure of the line drawing is performed. This is because the number of pixels is calculated for each of the independent regions (hereinafter, simply referred to as “independent regions”) included in the line drawing, and the independent regions having a predetermined number of pixels or less are recognized as pinhole regions. This is a process of changing the color of the hole area to the same color as the surrounding color. In the example of FIG.
H1 and PH2 are erased as pinholes.

In step S3, the operator sets the color C
The line drawing displayed on the RT 44 is observed, and a line break visible with the naked eye is manually connected. In the example of FIG. 3A, since the region R1 includes the line break CT1, this portion is connected in black. In the manual connection process, the operator specifies the positions of two points on the screen and specifies the width and color of a straight line connected by these two points. In response to these instructions, the line drawing processing device 20 connects the specified two points with a straight line having a specified width and a specified color. FIG. 3 (B)
Shows a line drawing obtained by erasing the pinholes PH1 and PH2 and connecting the visible line break CT1.

The black region R1 shown in FIG. 3B still contains a line break CT2, which is assumed to be invisible to the naked eye. FIG. 3 (B) (and FIG.
(A)), for convenience of illustration, the broken line portion CT2 is enlarged.

Steps S4 to S6 in FIG. 2 are processing for detecting and connecting line breaks which cannot be directly observed with the naked eye. First, in step S4, a region that is a candidate for a line break (hereinafter, referred to as a “line break candidate region”) is detected.

FIG. 5 is a flowchart showing a detailed procedure of the line break candidate area detection process in step S4. FIG. 6 is an explanatory diagram showing the processing content in step S4. FIG. 6A is an enlarged view of the black region R1 shown in FIG. 3B, and the line break CT2 is exaggerated.

In step S41, the image area having the line color number # 1 is thickened by a predetermined deformation width Wt, and a new color number is assigned to the additional area created by the thickening. In this embodiment, the color number # 1 is used as the line color number, but an arbitrary color number can be specified as the line color number.

As a result of the processing in step S41, FIG.
As shown in the figure, an additional region SR having a new color number # 2 and a width Wt is formed outside and inside the image region R1 of the color number # 1. Note that, as the deformation width Wt, a value of about １ ／ of the maximum width of the gap at the line break is specified in advance.

The fattening process in step S41 is performed as follows:
This can be realized by a process using a window operator such as a nearby window or a four-neighbor window, or by expanding the outline of the image region R1 of the color number # 1 to the outside. .

In step S42, the image area having the background color number # 0 is thickened by the deformation width Wt. However, at this time, the image region R1 having the line color number # 1 is not eroded by the image region having the background color number # 0. The process of not eroding the area of the color number # 1 is called “protecting the color number # 1”.
The line drawing in FIG. 6C is a line drawing obtained by the processing in step S42. This line drawing includes an image region R1 of the color number # 1 and additional regions SR1 to SR5 remaining after the thickening process in step S42.

In step S42, color number # 0
The process of thickening the area is performed by using the area of the color number # 1 and the color number #
This is equivalent to the process of narrowing the sum area of the two areas. However, also in this case, it is necessary to protect the area of the color number # 1.

In step S43, the line drawing thus obtained is subjected to region separation processing (also referred to as "region division processing") to identify independent regions included in the line drawing.
When the area separation process is performed on the line drawing of FIG. 6C, the areas BG1 and BG2 of the color number # 0, the area R1 of the color number # 1, and the areas SR1, SR2 and SR of the color number # 2 are obtained.
3, SR4 and SR5 are each identified as a separate independent region. It should be noted that the color number of each independent area is kept as it is even when the area is recognized as an independent area by the area separation processing.

In step S44, an area having the color number # 2 of the additional area (ie, additional area) in the independent area.
For each of SR1 to SR5, the number N of color changes around it is determined, and the color number of the additional area is changed according to the value of N. As will be described later, an additional area in which the number N of color changes in the surrounding area is 4 or more is recognized as a line break candidate, and coordinates representing the area are stored in the memory.

FIG. 7 is a flowchart showing the details of the process in step S44. FIG. 8 is an explanatory diagram showing the processing contents of the procedure of FIG. In step T1, one additional area is selected. The additional region SRa in FIG.
For convenience of description, additional regions SR1 to SR shown in FIG.
5 is different.

In step T2, the additional region SRa is painted with the color number # 3, and the minimum value (xmin, ymin) and the maximum value (xmax, xmax, xmin) of the coordinates of the pixels included in the additional region SRa.
ymax) (see FIG. 8A). Note that “painting with color number # 3” means changing the color number of the run-length data of the additional area SRa to # 3.

In step T3, (xmin−1, ymin
-1) to (xmax + 1, ymax + 1)
The additional region SRa is made thicker by one pixel. In this fattening process, the four neighboring windows W1 shown in FIG.
min-1, ymin-1), (xmax + 1, ymax + 1)
Are sequentially moved within the rectangular area defined by
If the color number of # 1 is # 0 or # 1 and at least one of the four peripheral pixels is # 3, the color number of the center pixel CP1 is changed to # 4 or # 5. At this time, the color number is changed to # 4 for the portion where the original color number was # 0, and the color number is changed to # 5 for the portion where the original color number was # 1.
Change to FIG. 8C shows the line drawing thus obtained.

In step T4, the number N of color changes around the additional region SRa (hereinafter, referred to as the "color change number") is obtained using the eight neighborhood windows W2 shown in FIG. 8D. As shown in FIG. 8D, eight peripheral pixels of the eight neighboring windows W2 are assigned priorities of 1 to 8. In the process of step T4, the center pixel CP2 is arranged at each pixel in the regions of the color numbers # 4 and # 5, and the color number # 4
Also, the color number of the peripheral pixel having the highest priority among the peripheral pixels of # 5 (hereinafter referred to as “priority peripheral pixel”) is checked. Then, the color number of the priority peripheral pixel and the central pixel CP
If the color number is different from the color number 2 (that is, if one is # 4 and the other is # 5), it is determined that the color has changed, and the number of color changes 1 is counted. On the other hand, when the color number of the priority peripheral pixel is equal to the color number of the center pixel CP2, it is determined that there is no color change. In this manner, the number N of color changes around the additional region SRa is obtained by applying the center pixel of the 8-neighbor window W2 to each pixel of the color numbers # 4 and # 5. In the specific processing of step T4, two points (xmin−2, ymin
-2), the eight neighboring windows W2 are sequentially moved in the main scanning direction y within the rectangular area defined by (xmax + 2, ymax + 2), and the color number of the center pixel CP2 is # 4 or # 5. The presence or absence of the color change as described above is determined.

FIGS. 8E and 8F show the case where the center pixel CP2 of the 8-neighbor window W2 is arranged at the points P1 and P2 in FIG. 8C, respectively. In the case of FIG. 8E, since the color number # 4 of the priority peripheral pixel (indicated by a circle in the figure) is different from the color number # 5 of the central pixel, it is determined that there is a color change, and The value of the number N increases by one. On the other hand, in the case of FIG. 8F, since the color number # 4 of the priority peripheral pixel is equal to the color number # 4 of the center pixel, it is determined that there is no color change, and the number N of color changes remains unchanged. Is kept. If such processing is performed on the areas of color numbers # 4 and # 5, the number N of color changes around the additional area SRa can be obtained.

In step T5, it is determined whether the value of the color change number N is 4 or more. FIG. 9 is an explanatory diagram showing a case where the value of the color change number N is equal to 2, 4, and 6, respectively. As can be seen from FIG. 9, the number N of color changes around the additional area is an even number. Further, the additional area where the color change number N is 2 as shown in FIG. 9A is an area originally formed in a fine portion other than the line break. On the other hand, FIG.
As shown in (B) and (C), the additional area where the color change number N is 4 or more is an area formed in a relatively small gap such as a broken line. Therefore, when the color change number N is 4 or more, the additional area is recognized as a line break candidate area, and candidate area display coordinates CDISP ((xmin + xmax) / 2, ( ymin +
ymax) / 2) and the candidate area processing coordinates CPROC (xmin, y
1) is stored in the memory. FIG. 10 is an explanatory diagram showing an example of the candidate area display coordinates CDISP and the candidate area processing coordinates CPROC. The candidate area display coordinates CDISP are, as described later,
These coordinates are used when the position of the line break candidate area is displayed on the color CRT 44, and include an average value of the maximum coordinates and the minimum coordinates of the line break candidate area. As will be described later, the candidate area processing coordinates CPROC are used as coordinates indicating the start point of the processing when performing the repair processing of the line break candidate area. The main scanning coordinate y1 of the candidate area processing coordinates CPROC is the minimum y-coordinate value at the minimum value xmin of the sub-scanning coordinates of the line break candidate area.

In step T6, the color number # 3 of the additional area to be processed is kept as it is. That is, the color number is maintained at # 3 for the additional area determined as the line break candidate area. On the other hand, if the color change number N is less than 4 (that is, N = 2) in step T5, the area of color number # 3 (the additional area to be processed) is painted out with color number # 0 in step T7. (See FIG. 9A). The process of step T7 is equivalent to erasing the additional area.

As described above, for the additional area determined as the line break candidate area, the candidate area display coordinates CDISP and the candidate area processing coordinates CPROC indicating the points representing the area in step T6 are stored in the memory. The color number of the line break candidate area is kept at # 3. On the other hand, the area determined to be not the line break candidate area is erased by changing the color number of the area to the color number # 0 indicating the background color in step T7.

When step T6 or T7 ends, in step T8, the areas of color numbers # 4 and # 5 are changed to the original color numbers # 0 and # 1, respectively. This is because the areas of the color numbers # 4 and # 5 are formed for convenience in order to check the number N of color changes around the additional area. In step T9, it is determined whether or not the processing in steps T1 to T8 has been completed for all the additional regions included in the line drawing. If not, the process returns to step T1, and the above-described step T1 is performed for the next additional area.
To T8 are executed.

FIG. 6D shows the result of executing the processing of FIG. 7 on the line drawing of FIG. 6C. Of the five additional regions SR1 to SR5 shown in FIG. 6C, the additional regions other than the first additional region SR1 have been deleted, and the color numbers of the first additional region SR1 are # 2 to # 2. It has been changed to 3.

When the processing in FIG. 7 (ie, the processing in step S44 in FIG. 5) is completed, the processing in step S5 in FIG.
Is executed. In step S5, it is determined whether or not a line break candidate area exists in the line drawing. If there is no line break candidate area, the process proceeds to a coloring process in step S7 described later. On the other hand, if there is a line break candidate area, processing for repairing the line break candidate area is executed in step S6.

FIG. 11 is a flowchart showing the procedure of the repair processing of the line break candidate area in step S6.
In step S61, it is determined whether or not all the line break candidate areas are automatically repaired. When processing a line drawing including only large line drawing parts such as illustrations and ruled lines, the operator selects automatic repair of all the candidate regions because the line break candidate region is always a line break. On the other hand, when the line drawing includes a fine line drawing part such as a character, there is a possibility that the line break candidate area is a part of a fine part such as a character, so the individual selective repair is selected.

If it is instructed in step S61 to automatically repair all candidate areas, in step S62 all candidate areas are painted out with line color number # 1. Since color number # 3 is assigned to the line break candidate area, the process of step S62 is a process of changing the color number in the run-length data from # 3 to # 1. FIG.
As can be seen from (D), since the line break candidate region SR1 fills the gap of the line break CT2 of the region R1 representing the line, the color number # 3 of the line break candidate region SR1 is replaced with the line color number # 1. Is substantially changed to the line break CT
2 can be connected. When the color number is changed, the candidate area processing coordinates CPROC (FIG. 10) are used.
The color number of the pixel connected to the pixel at this coordinate position is sequentially # 3
From # 1 to # 1. Note that the detection of connected pixels is
A neighboring algorithm is used. As described above, by using the candidate area processing coordinates CPROC, the repair of the line break candidate area can be surely executed.

In step S61 of FIG. 11, when it is not instructed to automatically repair all candidate areas,
In step S63, it is determined whether an unprocessed line break candidate area exists. If there is an unprocessed candidate area, one of the line break candidate areas is selected in step S64, and the operator specifies a mode for repairing the candidate area. In step S64, one candidate area display coordinate CDISP previously stored in the memory is read out, and the pixel at that position (or several pixels around it) is read out.
Is displayed on the screen of the color CRT 44 so as to be clearly distinguished from the colors of other image areas. For example, when the line drawing is displayed as a black and white image on the color CRT 44, the position of the candidate area display coordinates DDICP is displayed in a conspicuous color such as red.

The repair mode includes an automatic repair mode,
There are three modes: manual repair mode and erase mode. When the automatic repair mode is selected in step S64, the line break candidate area to be processed is painted with the color number # 1 in step S65.

When the manual repair mode is selected in step S64, the line break candidate area to be processed is painted out with the color number # 0 in step S66. This is equivalent to erasing the line break candidate region. Then, in step S67, the broken line portion is repaired by a manual operation. As manual repairs,
Specify two end points of a straight line and connect them with a predetermined width.
So-called straight line drawing processing can be used.

When the erase mode is selected in step S64, in step S68, the line break candidate area to be processed is painted out with the color number # 0 and erased.

By the processing of steps S64 to S68, 1
When the repair of the two line break candidate areas is completed, step S6
Returning to 3, it is determined again whether or not there is an unprocessed line break candidate area. Thus, the processing of steps S63 to S68 is repeatedly executed for each line break candidate area.

As described above, when displaying the line break candidate area on the color CRT 44, the candidate area display coordinates CDISP
Indicates the center position of the line break candidate area, so that the operator can easily determine how to repair. The pixel at the position of the candidate area display coordinates CDISP may not be included in the line break candidate area. However, since the color number is changed from the pixel at the candidate area processing coordinates CPROC, the repair processing of the line break candidate area is surely performed. Can be performed. In this way, by storing the candidate area display coordinates CDISP and the candidate area processing coordinates CPROC as the coordinates representing each of the line break candidate areas, the line break can be easily and reliably repaired. Becomes However, only one coordinate (for example, only the candidate area processing coordinates CPROC) may be stored as the coordinates representing the line break candidate area.

When the repair of the line break candidate region in step S6 is completed, a line drawing coloring process is executed in step S7 (FIG. 2). The coloring process is a process in which an operator designates regions in a line drawing one by one and fills the regions with a desired color. When the coloring process is completed for the desired area in steps S7 and S8, a line drawing is output in step S9. In this embodiment, a mesh image of a line drawing is recorded on a photosensitive film by the recording scanner 50 in step S9.

As described above, in the above-described embodiment, the region R1 having the line color number # 1 is thickened by the predetermined deformation width Wt (FIG. 6B), and thereafter the background color number # 0 is provided. By increasing the area by the deformation width Wt, the additional area S
R1 to SR5 are formed (FIG. 6C). When the number N of color changes around each additional region is 4 or more, the additional region is recognized as a line break candidate region, so that a line break can be easily recognized. Further, if the line break candidate region is formed by the above method, it is possible to form the line break candidate region regardless of the direction of the gap at the line break. Further, color number # 3 of the line break candidate area
Is changed to only the line color number # 1 so that the line break can be easily connected.
If a fine part that is not originally a line break, such as a fine part of a character, is recognized as a line break candidate area, the color number of this candidate area is simply changed to # 0, and the candidate area is changed to # 0. It can be easily erased. As described above, in the above-described embodiment, it is possible to easily detect and connect a portion to be connected as a broken portion, and to keep a fine portion that is not a broken portion as it is.

The present invention is not limited to the above-described embodiment, but can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) The number N of color changes around the additional area
Various methods other than the method shown in FIG. FIG. 12 is an explanatory diagram showing a method that is an alternative to the method of FIG. By applying the 8-neighbor window W3 shown in FIG. 12B to the additional region SRa shown in FIG. 12A, as shown in FIG. 12C, a peripheral region PR1 is formed around the additional region SRa. ~ PR4
To form That is, when the central pixel CP3 of the eight neighboring window W3 has the color number # 0 or # 1 and at least one of the eight peripheral pixels has the color number # 3, the pixel is regarded as a pixel in the peripheral area. As a result, peripheral regions PR1 to PR4 are obtained. Since the peripheral regions PR1 to PR4 formed using the eight neighboring windows are connected to each other, these peripheral regions PR1 to PR4 are connected to each other.
By detecting the number of color changes in No. 4, the number of color changes N around the additional region SRa can be obtained. Note that, similarly to the example of FIG.
New color numbers may be assigned to 1 to PR4.

(2) In the above embodiment, the line drawing is represented by the run-length data. However, the line drawing may be represented by bitmap data. Note that when run-length data is used, it is possible to execute the fattening process or the thinning process as it is with the run-length data. However, after the run-length data is converted into bitmap data, the fattening process or the thinning process is performed. You may make it perform a convergence process.

(3) In the above embodiment, the deformation width Wt is assumed to be a value of about 1/2 of the maximum width of the gap to be detected as a line break, but the value of the deformation width Wt is as follows. It is preferable to determine in consideration of the following. FIG. 13 shows the line width t1.
FIG. 9 is an explanatory diagram showing that the shape of an additional region differs according to the relationship between the additional region and the gap t2. FIG. 13A shows the line width t1.
13 is larger than the gap t2, and shows the result of executing the thickening process in step S41 and step S42 in FIG. 5, and FIG.
The result of executing the fattening process and the thinning process for a case smaller than 2 is shown. When t1> t2 (FIG. 13
In (A)), a part SRR of the additional region SR formed by the thickening process for the color number # 1 remains after the thickening process for the color number # 0, whereas the tR1
In the case of <t2 (FIG. 13B), all the additional regions SR formed by the thickening process for the color number # 1 have disappeared by the thickening process for the color number # 0. This is for the following reasons. The minimum value of the width of the additional region SR is given by the width Wg in the gap portion of the line, and the value of the width Wg is substantially equal to the line width t1 in both cases of FIGS. Therefore, when the thickening process of the color number # 0 is performed with the deformation width Wt smaller than the width Wg = t1 as shown in FIG.
, The width Wg = t1 as shown in FIG.
This is because if the thickening process of the color number # 0 is performed with a larger deformation width Wt, the additional region SR disappears.

As shown in FIG. 13, it is difficult to automatically detect a line break having a gap larger than the line width t1, but usually it can be detected visually in most cases. Can be processed. On the other hand, in order to detect a broken portion having a gap equal to or less than the line width t1, it is understood that the deformation width Wt may be set to a value of about 以下 or less of the line width t1. In particular, if the deformation width Wt is set to about の of the line width t1, it is possible to detect and connect almost all line breaks having gaps equal to or smaller than the line width t1.

[0063]

As described above, according to the first aspect of the present invention, among the additional areas formed by the two fattening processes, those having a surrounding color change number of 4 or more are lined. Since it is detected as a break candidate region, there is an effect that a line break candidate region can be easily detected regardless of the direction of the gap.

According to the second aspect of the present invention,
There is an effect that the wire break can be easily connected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a line drawing processing device 20 that processes line drawing data by applying an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a procedure of a line drawing process.

FIG. 3 is a plan view showing a line drawing to be processed in the embodiment.

FIG. 4 is a conceptual diagram showing the structure of line drawing data.

FIG. 5 is a flowchart showing a detailed procedure of a line break candidate area detection process.

FIG. 6 is an explanatory diagram showing the details of a line break candidate area detection process.

FIG. 7 is a flowchart showing details of the process in step S44.

FIG. 8 is an explanatory diagram showing the processing content of step S44.

FIG. 9 is an explanatory diagram showing processing contents according to the number N of color changes.

FIG. 10 is an explanatory diagram showing an example of candidate area display coordinates and candidate area processing coordinates.

FIG. 11 is a flowchart showing the procedure of a repair process for a line break candidate area.

FIG. 12 is an explanatory diagram showing another method for obtaining the number of color changes around an additional area.

FIG. 13 is an explanatory diagram showing a shape of an additional area according to a relationship between a line width and a gap.

[Explanation of symbols]

 Reference Signs List 20 line drawing processing device 22 CPU 24 bus 26 ROM 28 RAM 32 line drawing memory 34 keyboard I / O interface 36 keyboard 38 mouse 42 display control unit 44 CRT 44 color CRT 46 Image data input / output interface 50: recording scanner 60: flat scanner SL: scanning line SR: additional area Wt: deformation width

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-208178 (JP, A) JP-A-1-119874 (JP, A) JP-A-4-239387 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G06T 5/00-5/50 G06T 7/00 G03F 1/00 H04N 1/40-1/409

Claims (2)

(57) [Claims] 1. A method of processing a line cut portion of a line drawing by processing line drawing data representing a first line drawing in which a line of a second color is drawn on a background of a first color. hand,
(A) forming an additional region around the image region by thickening the image region of the second color by a predetermined width in the first line drawing, thereby generating a second line drawing; (B) the first line drawing included in the second line drawing;
(C) generating a third line drawing by thickening the image region of the color of the third line drawing by the predetermined width; and (C) determining the number of color changes around the additional region remaining in the third line drawing. A line break processing method comprising: a checking step; and (D) detecting the additional area as a line break candidate area when the number of color changes is four or more. 2. The line break processing method according to claim 1, further comprising: (E) filling the line break candidate area with the second color, thereby forming a line break existing in the first line drawing. And a step of connecting the parts.