JP2639488B2 - Wire break connection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
It is called "composition image". ) Based on the binary image data
The present invention relates to a method of detecting a broken line portion of a composition image and connecting it.

[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 process (flat screen refining) for filling a part of an image in a desired uniform color is performed in a plate making process. In recent image processing systems, there is a system that automatically performs flat screen binding, which has been performed manually until now. In such a system, the binary image data of the composition image is read by an image reading device, and a desired closed area in the composition image is filled with a desired color by an image processing device, thereby performing flat-screening. There is.

[0004] Such a "painting process in a closed area"
Is performed, there is a case where a line image that should originally form a closed region in the composition 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 position of the line break was
Was searched directly from the composition image displayed in, and the composition was modified to connect the cut 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 finding and connecting a broken line in an image, for example, a method using a vectorization technique of a binary image as disclosed in Japanese Patent Application Laid-Open No. 61-139892 has been proposed. Have been.

An image processing apparatus for processing a line image (hereinafter referred to as a "line image processing apparatus") performs relatively simple image processing of switching the level of binary image data for each pixel. Vector data processing for vectorizing a binary image is a relatively complicated process, and its processing device is also complicated and relatively expensive. Therefore, when the function of vector data processing is added to the line drawing processing device, there is a problem that the cost of the line drawing processing device is greatly increased. Further, 100% of line breaks cannot be detected even by a method using vectorization technology, so that an operator often checks whether or not there is a line break at the end.
There is also a problem that the entire processing time is not necessarily shortened.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and makes it easy to find and connect line breaks in an image without using a complicated vectorization technique. It is an object of the present invention to provide a method for connecting a broken wire portion.

[0009]

In order to solve the above-mentioned problems, a method for connecting a line break portion according to the present invention comprises the steps of: (a) selecting a line image in a line image displayed on a display unit ;
Based on the pixel value assigned to the element,
Recognize mutually independent areas separated by boundaries
And different colors in the mutually independent areas
While assigning each area part with the assigned color
The line drawing image is displayed on the display means to form a closed area.
Compare the inner color of the power line element with the outer color and
To include line drawing elements where the color of the part and the external color are the same
In the step of designating the processing target area, (b) examining the image data representing an image of the processing target area, in the image area having a color different from the color of the line drawing portion,
Detecting a portion having a width equal to or less than a predetermined threshold value as the line break ; and (c) changing the color of the line break detected in the step (b) to the color of the line drawing portion. by modifying, and a step of connecting the wire breakage portion.

Here, the term "line drawing" generally means an image drawn with lines and planes having a uniform density, and is a term that includes not only images such as figures but also character images.

[0011]

In general, the width of a broken line is very small. Therefore, in the line drawing image , in the image region having a color different from the color of the line drawing part, the width has a width equal to or smaller than the predetermined threshold.
If there is a portion, the portion can be detected as a broken line. If the color of the line break is corrected so as to have the same color as the line drawing portion, the line break can be connected.

In addition, when an independent area portion of the entire line drawing image is displayed in different colors before designating the processing target area, the internal color and the external color of the line drawing element which should constitute the closed area are displayed. Are the same, it is known that there is a line break somewhere in the line drawing element. Therefore, if the processing target area is specified so as to include the line drawing element, only the area including the line break can be specified as the processing target, and the line break connection processing can be performed efficiently.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Configuration of Apparatus FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus that performs an image line break connection process by applying an embodiment of the present invention. This image processing apparatus has the following components.

(A) Image input device 1: A device for reading an underprint image and obtaining a binary image thereof, and is constituted by a flat scanner or the like. (B) Run-length compression unit 2: Run-length compression of the binary image data read by the image input device 1 to generate run-length data. (C) Image memories 31, 32: memories for storing the run-length data of the composition image provided from the run-length compression unit 2 and the CPU unit 6 described later. First image memory 31
Stores the run-length data of the composition image and the run-length data of the composition image to which the line break is finally connected. The second image memory 32 is a memory temporarily used in processing for detecting and connecting line breaks, and stores data of an image area designated by an operator, as described later. (D) Run-length expansion unit 4: expands the run-length data supplied from the image memories 31 and 32 into bitmap data.

(E) Color monitor section 5: An apparatus for displaying image data given from the run length extension section 4 and the CPU section 6, and includes the following components. Display memory 51: A memory for storing bitmap data of an image to be displayed. Color palette 52: The color numbers (described later) included in the image data provided from the display memory 51 are represented by R (red), G (green), and B (blue).
To a luminance signal. The color number is specified for each image area of the composition image. Color monitor 53: Displays a color image. Display control unit 54: Controls display of an image on the color monitor 53. Further, the color information (information indicating the correspondence between the color numbers and the luminance signals of the three primary colors) stored in the color palette 52 is rewritten, and the position of the display cursor on the color monitor 53 is controlled so as to correspond to the movement of the mouse. .

(F) CPU unit 6: A device for controlling the entire image processing apparatus and performing necessary calculations, and has the following components. Control operation unit 61: control of each unit of the image processing apparatus, and extraction, division, and
Calculations such as area separation and thinning processing of image data are performed.
Auxiliary memory 62: A memory for storing temporary information required in the course of various processes. Mouse 63: Used for designating a processing target area or the like on an image displayed on the color monitor 53. (G) Image output device 7: records an image to which a line break has been connected on a recording medium such as a film.

B. Processing Procedure FIG. 2 is a flowchart illustrating a procedure of a line break detection process and a connection process. In step S1, characters and graphics are first arranged on a mount to prepare a composition. Figure 3 shows the composition B
It is a top view showing the example of C. In the composition BC, square and circular figures are arranged on a white mount BS, and characters such as "DS" are arranged below these figures.
These figures and characters are drawn in black.

In step S2, the image input device 1 reads the binary image data Db of the composition BC. The binary image data Db is data indicating whether each pixel in the composition image is black or white. In step S3, the binary image data Db is sent from the image input device 1 to the run length compression unit 2, where it is converted into run length data Dr. 4 and 5
Is an explanatory diagram showing the configuration of run-length data Dr.

FIG. 4 is an enlarged view of only the character A portion of the composition image. In the figure, it is assumed that the vertical direction is the main scanning direction Y and the horizontal direction is the sub-scanning direction X. The coordinate range in the main scanning direction Y on the mount is 0 to 150.
It is assumed that there is.

FIG. 5 shows the configuration of the run-length data Dri at the sub-scanning coordinates Xi for the copy image. The run-length data Dri includes four continuous data Dri (1) to Dri (4) (hereinafter, referred to as “unit run-length data”). Each of the unit run-length data Dri (1) to Dri (4) is composed of 32 bits, and the most significant 1 bit is black-and-white designation data Dwb indicating whether the unit run-length data is black or white. 15 bits are system color data Dsc indicating a system color number to be described later, and lower 16 bits.
The bit is coordinate data Drc indicating the main scanning coordinate of the start point of the unit run length.

As shown in FIG. 4, in the sub-scanning coordinates Xi,
The section where the main scanning coordinate Y is from 0 to 99 is white, the section from 100 to 119 is black, and the section from 120 to 150 is white. Three unit run length data Dri
(1) to Dri (3) indicate the main scanning coordinates of the start points of the above three sections and whether the section is white or black.
The value of the main scanning coordinates of the fourth unit run-length data Dri (4) is the maximum value (= 150), indicating that the run-length data for this main scanning line has been completed. At this point, since the system color has not been determined, the system color data Dsc in the run-length data has a value that has no particular meaning.

The run-length data Dr obtained as described above is supplied from the run-length compression unit 2 to the first image memory 31 and stored therein. In addition, based on the run length data Dr, the copy image is displayed on the color monitor 53.
Will be displayed. However, the image displayed here is a black-and-white image.

In step S4, a region separation process is performed on the entire composition image. The region separation process refers to a process of distinguishing mutually independent regions separated by a boundary line between a black portion and a white portion, and assigning a different number (system color number) Ns to each of the distinguished regions. FIG.
FIG. 4 is an explanatory diagram showing each image region separated by the region separation processing. The composition image consists of 10 image areas (hereinafter referred to as
It is called "isolation region". ) R1 to R10. The value of the system color number Ns is 1 in each of the separation areas R1 to R10.
To 10 respectively. This system color number Ns is registered as system color data Dsc of each unit run-length data Dri (FIG. 5). As shown in FIG. 6, it is assumed that the circle graphic C has one line break CP1.

The number assigned to each separation area is called a system color number, because this number is automatically assigned by the control operation unit 61 and can be used as a number representing a color. The details of the area separation process
Further details will be described later. The image after the region separation processing is displayed on the color monitor 53. At this time, in order to display the entire composition image on the color monitor 53, the image data subjected to the thinning process by the control calculation unit 61 is provided to the display memory 51. In addition, the color palette 52 stores each system color number Ns.
Are converted into colors different from each other, and the separation regions R1 to R10 are displayed in different colors.

FIG. 7 is a conceptual diagram showing an image displayed on the color monitor 53. Since the line break is usually very thin (about several tens of μm), it is difficult to visually check the line break CP1 of the circular figure C on the thinned image. However, if each of the image regions R1 to R10 is displayed in color according to the system colors assigned in the region separation processing, it becomes easy to find line breaks for the following reasons. If there is no line break in an image area where a closed loop is to be formed (circular figure C in the examples of FIGS. 6 and 7), the inside and outside of the image area are displayed in different colors. On the other hand, as shown in FIG.
If there is 1, since the inside and the outside become the same image area, they are displayed in the same color. Therefore, the operator observes the color image displayed on the color monitor 53 and searches for a closed-loop image area in which the color of the internal area is the same as the color of the external area, so that the closed-loop image area having a line break is determined. Can be easily found.

In step S5, when the operator observes the color monitor 53 and finds that a broken line exists somewhere (for example, in the circle C), the process proceeds to step S5.
Steps 6 and after are performed, and the detection of the position of the line break and the connection processing are performed. First, in step S6, the operator designates an area PR (hereinafter, referred to as a "processing target area") in which connection processing of a line break is performed on the composition image displayed on the color monitor 53. The PR image data is stored in the second image memory 32.

As shown in FIG. 7, the processing target area PR is a rectangular area and has sides drawn in parallel in the main scanning direction X and the sub-scanning direction Y from each of the two vertices P1 and P2. ing. When the operator specifies the positions of the two vertices P1 and P2 using the mouse 63 in the composition image displayed on the color monitor 53, the image data of the image in the processing target region PR is extracted from the first image memory 31. And is stored in the second image memory 32. The first
The image data of the original composition image is stored in the image memory 31 as it is. FIG. 8 shows an enlarged image of the extracted processing target region PR.

In step S6, the display color number Nd of the line drawing element (circular figure C in the example of FIG. 7) to be processed is designated by the operator as the line drawing display color number LNd. The display color number Nd is a number indicating a color when an image is displayed on the color monitor 53, and is a number given independently of the above-described system color number. In the composition image, black and white are display colors. For example, when specifying the display color of the circular graphic C, a number (for example, 1) indicating black is specified as the line drawing display color number LNd. The display color is specified by, for example, displaying a display color menu on the color monitor 53 and using the mouse 63 to select one of many display colors. Instead of the operator specifying the value of the line drawing display color number LNd as described above, a value representing black may be set in advance.

In step S7, the operator designates whether or not the processing for detecting and connecting a broken line is to be performed automatically. Here, automatic is designated, and step S8 is executed. In step S8, the control calculation unit 61 automatically detects the line break CP1 in the processing target region PR and connects the line break CP1. FIG. 9 is a flowchart showing a detailed procedure of the process in step S8. The parameters used in the steps of FIG. 9 are defined as follows. Scanning position g: a parameter indicating the sub-scanning position of the scanning line to be processed. Run data counter k: A counter indicating the order of unit run length data on a scanning line to be processed.

First, in step S81, the processing target area P
The minimum sub-scanning coordinate X1 of R is set as the scanning position g. In step S82, the run-length data Drg of the scanning position g in the processing target area PR is stored in the second image memory 3
2 and stored in the auxiliary memory 62.

In step S83, it is determined whether or not two or more of the unit run-length data of the run-length data Drg have the value of the black and white designation data Dwb equal to the line drawing display color number LNd designated in step S6. Can be examined. In step S6, the line drawing display color number LNd = 1 (black)
Therefore, if there are two or more unit run-length data of Dwb = LNd, there is a possibility that there is unit run-length data representing a white line break between the unit run-length data. If the unit run length data of Dwb = LNd is one or less, there is no unit run length data representing the line break at this coordinate position g, so steps S84 to S90 are omitted, and step S91 described later is executed. You.

On the other hand, if there are two or more unit run-length data of Dwb = LNd, there is a possibility that unit run-length data representing a line break may exist at the coordinate position g. Be executed. FIG.
0 is a conceptual diagram showing run-length data Drg at the sub-scanning coordinates Xg shown in FIG. 8 and a linear image area represented by the run-length data Drg. FIG.
In the case of 0, since there are three unit run-length data of Dwb = LNd = 1, step S84 and subsequent steps are executed.

In step S84, n continuous unit run-length data are extracted from the unit run-length data Drg at the coordinate position g so as to include all the unit run-length data for which Dwb = LNd. In the example of FIG. 10, five consecutive unit run-length data Drg
(2) to Drg (6) are extracted. Therefore, n = 5.

In step S85, the value of the run data counter k is initialized. In this initialization, step S84
Run-length data Drg (2) to D extracted in
The minimum value of the counter values 2 to 6 specifying rg (6) is set as the value of the run data counter k. Step S
In 86 to S88, the unit run length data Drg
It is determined whether or not (k) indicates a line break, and if it indicates a line break, connection processing is performed.

First, in step S86, the unit run-length data Drg specified by the run data counter k
It is checked whether the value of the black-and-white designation data Dwb (k) in (k) is equal to the line drawing display color number LNd. Dwb = LN
In the case of d (representing black), since this unit run-length data Drg (k) is not a line break, the process proceeds to step S89 described later.

On the other hand, when Dwb を LNd (representing white), in step S87, the run length represented by the unit run-length data Drg (k) is compared with a predetermined line break maximum width d. . As shown in FIGS. 4 and 5, the coordinate data Drc (k) of the unit run-length data Drg (k) indicates the main scanning coordinates of the start point of the unit run-length data. [Drc
(K) -Drc (k-1)]. The value of the maximum width d of the line break is a preset threshold value. For example, when the screen ruling is 2000 lines / inch,
As shown in FIG. 10, d is set to a value of about 5 (pixel).

If the run length is equal to or smaller than the line break portion maximum width d, the unit run length data Drg (k) corresponds to the line break portion. Therefore, in step S88, the unit run length data Drg (k) ) Black and white designation data Dw
The value of b is set to the value (= 1) of the line drawing display color number LNd. In the case of FIG. 10, the unit run-length data Drg
Run length of (5) [Drc (5) -Drc (4)] = 4
Is smaller than the maximum line width d = 5, the value of the black-and-white designation data Dwb (5) is corrected to 1. As a result, the white line cut portion is changed to black, and is connected to the black portions before and after it. On the other hand, if the run length is larger than the line break maximum width d, the unit run length data Drg (k) does not correspond to the line break, so that step S88 is omitted and the process proceeds to step S89. .

In step S89, it is checked whether or not the value of the run data counter k is equal to n. If the run data counter k is not equal to n, the parameter k is incremented by one in step S90, and the process returns to step S86 to process the next unit run length data. On the other hand, when the parameter k is equal to n, the unit run-length data Drg (1) to Drg of the current scanning position g
Since the processing of (n) has been completed, the flow shifts to step S91.

In step S91, the value of the scanning position g is set to 1
One. If the value of the scanning position g is equal to or smaller than the maximum value X2 of the sub-scanning coordinates of the processing target region PR in step S92, the process returns to step S82 to process the run-length data at that scanning position. On the other hand, when the value of the scanning position g exceeds the maximum value X2, the automatic connection processing of the line break is terminated.

By performing the processing of S81 to S92 as described above, the line break CP1 of the circular figure C is detected and connected. This process is automatically performed by the control calculation unit 61, and does not require an operator's judgment on the way, so that a line break can be detected and connected efficiently in a short time. The operator simply specifies in advance the processing target region PR, the line drawing display color number LNd, and the line break maximum width d.

Returning to FIG. 2, when the process of step S8 is completed, the process returns to step S4, where the whole copy image is again subjected to area separation, and the thinned image is displayed in the color monitor 53 by being classified by the system color. Then, in step S5, the presence or absence of a line break is determined. Step S4, S
The reason why Step 5 is executed again is that if there is a line break CP2 (shown in FIG. 11) parallel to the main scanning direction Y, the line break CP2 cannot be connected in the automatic connection process in step S8. .

On the image after performing the automatic connection process,
If there is still a line break, the area to be processed and the line drawing display color number are specified again (step S6), and manual connection of the line break is specified (step S7). Step S9
Steps S14 to S14 are processes for connecting a broken line according to an operator's designation, and are referred to as manual connection processes here.
In the following, a description will be given of a process of connecting the line break CP2 of the circular graphic Ca shown in FIG.

In step S9, the processing target region PR is bisected in the sub-scanning direction X. FIG. 11 shows a boundary line B for division.
L and two divided processing areas PR1 and PR2. If the coordinates of the vertices P1 and P2 of the processing target region PR are (X1, Y1) and (X2, Y2), respectively,
The division boundary line BL is represented by the following equation. X = (X1 + X2) / 2

The reason why the processing target region PR is divided in this way is that even if only one line break exists, its position can be easily detected. Assuming that the region separation processing is performed without dividing the processing target region PR, if only one line break (for example, only CP2) exists in the circular graphic Ca (FIG. 11), the entire circular graphic Ca is 1 Since the image is displayed as one separated area and is displayed in one system color, it is difficult to find the line break CP2 on the color monitor 53. On the other hand, as described above,
If the processing target region PR is divided into two, the circle graphic Ca is divided into two at the division boundary line BL. Therefore, even when there is only one line break, the line drawing before and after the line break can be obtained. The portions are distinguished from each other as different regions, and are displayed in different colors.

In step S10, the same region separation processing as described above is performed on each of the two divided processing regions PR1 and PR2. FIG. 11 also shows the regions R21 to R26 separated by the processing in this step. A system color number Ns is assigned to each of the separation areas R21 to R26.
For example, 21 to 26 are sequentially assigned. Circle figure C
If there is no line break in a, each divided processing area PR1, PR
The line drawing portions of the two circle figures Ca are each divided into one separation area, and only one system color number Ns is assigned. However, as shown in FIG.
Since there is a line break CP2 in a, the line drawing portion of the circular graphic Ca is separated into two separation regions R25 and R26 in the right division processing region PR2, and different system color numbers Ns are assigned to these separation regions. Can be

The system color number Ns assigned to each of the separation regions R21 to R26 is written in the system color data Dsc (see FIG. 5) in the run length data Dri.
Then, the run-length data Dri is stored in the second image memory 32. At this time, as shown in FIG. 13, a system color table SCT indicating the correspondence between each system color number Ns and the display color number Nd is created. In the system color table SCT, a display color number Nd = 1 indicating the display color (black) of the line drawing portion is registered in the separation regions R22, R25, and R26 corresponding to the line drawing portion, and the separation regions R21, A display color number Nd = 0 indicating the display color (white) is registered in R23 and R24.

In step S11, the density of the image (FIG. 11) of the processing target region PR is reduced. Density reduction generally refers to a process of obtaining a reduced image by reducing the number of pixels in an image in order to display the image on a monitor or the like. In this embodiment, it is assumed that a thinning process is executed. That is, for example, a 2 × 2 pixel block is thinned out to 1
One pixel. At this time, the display color number Nd of the pixel at a predetermined position (for example, the upper left pixel) in the 2 × 2 pixel block
And the system color number Ns are adopted as the display color number Nd and the system color number Ns of the thinned pixel.

The image data (run-length data) of the low-density processing target region PR is given from the control operation unit 61 to the second image memory 32 and stored. The image data of which density has been reduced is supplied to the color monitor unit 5, and the reduced image generated by the density reduction is displayed on the color monitor 53. At this time, according to the system color number Ns, the color pallet 52 stores the separated areas R21 to R2.
6 are painted in different colors, and the painted images are displayed on the color monitor 53.

In step S12, the operator visually inspects the image on the color monitor 53, and
Except for the intersection of L and the line drawing (circular figure Ca), the portion where the color of the line drawing changes (line cutout) CP2
Is detected. If there is no line break, each divided processing area PR
Since the color of the line drawing portion of the circular graphic C does not change in the PR1 and PR2, the line break CP2 of the circular graphic C can be found only by searching for the portion where the color has changed as described above. In a low-density image, the gap between the line breaks CP2 cannot often be seen, but if the color has changed as described above, the position where the line break exists can be easily found.

In step S13, as shown in FIG. 12, the operator specifies a region SR surrounding the line break CP2 on the color monitor 53. This specification is for mouse 6
3 is used to specify the positions of the two vertices Q1 and Q2 of the region SR. Specified area SR
Is enlarged and displayed on the color monitor 53 as shown in FIG. At this time, as shown in FIG. 14, the colors of the separation regions R25 and R26 corresponding to the line drawing portion of the circular graphic Ca may be displayed according to the display color number Nd (in this case, black).

In step S14, the operator performs processing for connecting the line break CP2 while looking at the enlarged display area SR. In this connection process, the operator specifies the points PP1 and PP2 with the mouse 63 in the two regions R25 and R26 separated by the line break CP2, and specifies a pixel between the two specified points PP1 and PP2. This is performed by giving an instruction to connect with the line segment SG. That is, this connection processing is performed for two designated points PP
This is a process of reassigning the same display color number Nd (or the same system color number Ns) to pixels between 1 and PP2.

The width of the line segment SG connecting between the two designated points PP1 and PP2 does not need to be approximately the same as the width of the circular graphic Ca, but only needs to be at least one pixel wide. This is 1
If the separation regions R25 and R26 are surely connected by the line segment SG having a width equal to or larger than the pixel, the inside and outside of the circular graphic Ca are painted in different colors due to the line break when performing the flat half-finish processing. It is because it can prevent that.

If the line break CP2 is very close to the dividing boundary line BL, it is difficult to confirm the position of the line break CP2 on the color monitor 53 in step S12. However, since it is confirmed in step S5 that a line break exists in the circle graphic Ca, the operator specifies an area including the position where the circle graphic Ca intersects with the dividing boundary line BL, and the image is displayed. If the display is enlarged, the broken line can be visually confirmed, and the connection processing can be performed in the same manner as described above.

When the connection process is performed, the coordinates of the two designated points PP1 and PP2 with respect to the origin O of the composition BC (see FIG. 3) are obtained by the control calculation unit 61. Further, the control calculation unit 61 corrects the original image data (run-length data) stored in the first image memory 31 so that the two designated points PP1 and PP2 are connected by a line segment SG.
Modify the image data representing the composition image. The image data corrected in this way is stored in the first image memory 31.

The image data after the correction is further subjected to various image processing such as flat-screening by the control calculation section 61. Then, the image data is supplied from the first image memory 31 to the image output device 7 via the run-length extension unit 4 in accordance with an instruction from the operator, and is recorded on a recording medium such as a film or a printing plate.

C. Details of region separation processing The region separation processing is performed, for example, as follows. FIG.
FIG. 5 is a diagram showing a processing window W used for the area separation processing. The pixel Pa indicated by hatching indicates a pixel to be processed, and the other pixels Pb to Pe are peripheral pixels of the pixel Pa.

The processing window W is sequentially moved along the main scanning direction Y from the smaller one in the sub scanning direction X.
When the pixel Pa is black, for example, the peripheral pixels Pb to Pb
If there is no black pixel in e, a new system color number Ns is assigned to the pixel Pa. On the other hand, the peripheral pixels Pb to Pb
e is a black pixel, the system color number N already assigned to the black peripheral pixel
Let s be the system color number Ns of the pixel Pa.

The same applies to the case where the pixel Pa to be processed is white. However, when the pixel Pa is white, and when the pixels Pc and Pe adjacent in the oblique direction are white and the other pixels Pb and Pd are black, the pixel Pc and Pe and the pixel Pa to be processed are
Are assigned different system color numbers Ns. In this way, when the white pixels are adjacent only in the oblique direction, it is recognized that these pixels form different areas. In this way, it is possible to avoid the area separation in which the black independent area and the white independent area cross each other.

As described above, in the process of moving the processing window W and sequentially giving different system color numbers Ns to independent regions, two or more system color numbers Ns may be given to the same region. . FIG. 16 to FIG. 19 are explanatory diagrams showing the procedure of the processing in such a case.

First, it is assumed that the composition image is composed of a black region Ra and three white regions Rb, Rc and Rd separated from each other by this region Ra as shown in FIG. When the processing window W is sequentially moved along the main scanning direction Y from the smaller one in the sub scanning direction X,
As shown in FIG. 17, different system color numbers Ns are assigned to the regions Ra to Rd.

In FIG. 17, the number written in each pixel is the system color number N assigned to that pixel.
s. Pixels to which no numeral is written indicate that the system color number Ns has not been assigned yet. As shown in FIG. 17, pixels assigned a system color number Ns = 2 are assigned to a black area Ra,
There is a pixel to which Ns = 4 is assigned. When the processing window W comes to the position of FIG.
Among the pixels adjacent to the system color number Ns of the pixel Pa
Is 2, the system color number Ns of the pixels Pd and Pe
Is 4. In this case, "the fact that Ns = 2 and Ns = 4 represent the same system color" is temporarily stored in the auxiliary memory 62, and the smaller system color number Ns = 2 is stored in the processing target pixel Pa. assign. When this is performed on all the pixels in FIG. 16, a system color image (an image painted in different system colors) in FIG. 18 and the same system color table IST in FIG. 20 are obtained.

In the same system color table IST, the system color numbers Ns = 2 and Ns = 4 represent the same system color (that is, assigned to the same image area), and Ns = 5 and Ns = 5. = 6 also indicates the same system color. The same system color table IST is stored in the auxiliary memory 62.

Next, the control operation unit 61 refers to the same system color table IST stored in the auxiliary memory 62, and is assigned a different system color number even though it is in the same image area. The process of reassigning a common system color number (for example, the smallest system color number among the same system color numbers) to pixels is shown in FIG.
8 is performed. As a result, as shown in FIG. 19, an image is obtained in which all the regions Ra to Rd are assigned different system color numbers Ns one by one.

Although the above description has been made with respect to processing on a pixel image, the same processing can be performed on image data that has been run-length compressed as shown in FIG. When performing segmentation processing on the run-length compressed image data, the run-length data of two adjacent scanning lines are read. Of the two scanning lines, the peripheral pixels Pc, Pd, and Pe on the left side of the processing window W in FIG. 15 exist on the scanning line near the coordinate origin, and the peripheral pixel Pb and the processing target pixel Pa on the second scanning line. Considered to be present.

Then, the run-length data of the two scanning lines are checked simultaneously, and in the first scanning line, the boundary of the separation region (that is, the boundary of the run length) is determined by the pixel Pc.
And between the pixels Pd and Pe, or between the pixels Pd and Pe, the colors of the peripheral pixels Pb-Pe are compared with the colors of the pixel Pa to be processed, and the pixel Pa
Assign a system color number. In addition, when the boundary of the separation area comes between the peripheral pixel Pb and the processing target pixel Pa on the second scanning line, the system color number of the processing target pixel Pa is similarly assigned.

In this way, by always assigning system color numbers while comparing run-length data on two scanning lines, it is possible to perform a region separation process based on the run-length compressed image data.

By performing the above-described region separation processing,
The respective regions in the processing target region PR are separated from each other, and the pixels in the single region are assigned the same system color number N
s is assigned. The system color number Ns is registered as system color data Dsc in each unit run-length data.

D. Modifications The present invention is not limited to the above embodiment,
The present invention can be implemented in various modes without departing from the gist of the present invention, and for example, the following modifications are possible. In the above embodiment, before designating the processing target region PR, in steps S4 and S5, a region separation process is performed on the entire composition image to find a line drawing element in which a line break exists. However, without performing step S4, the area including the line drawing constituting the closed area (closed curve) is set to 1
The processing after step S6 may be performed by designating each one.

However, as in the above embodiment, step S
If the steps S4 and S5 are performed, the detection of the line break and the joining process can be performed only on the line drawing having the line break, and therefore, there is an advantage that the entire composition image can be efficiently processed. In step S9 in the above embodiment, the processing target region PR is divided into two to perform the region separation processing. However, the present invention is not limited to the two divisions, and the region separation processing may be generally performed by dividing into two or more.

The shape of the processing target region PR and the shape of the region SR for displaying the enlarged image are not limited to rectangles, but may be any shapes. For example, the shape may be circular, or the operator may arbitrarily specify the shape of the area by tracing the outline of these areas with a mouse or the like.

Steps S9 to S14 shown in FIG. 2 are not necessarily performed, but if these processes are performed, even if there is a line break parallel to the main scanning direction, it can be connected. There is.

[0072]

As described above, the broken line of the present invention
According to the connection method , in the line drawing image , in an image region having a color different from the color of the line drawing portion , a value equal to or less than a predetermined threshold is used.
A portion having a lower width is detected as a line break, and the line break is connected by correcting the color of the line break so as to have the same color as the line drawing portion. Therefore, there is an effect that the process of detecting and connecting a broken line can be easily performed without requiring the judgment of the operator.

Further, according to the line break connection method of the present invention, before designating the processing target area, the independent area portion of the entire line drawing image should be displayed in different colors to form a closed area. Since the processing target area is specified so as to include a line drawing element in which the inside color of the line drawing element and the outside color are the same, for the line drawing element that should constitute a closed area, only the area including the line break is processed. Can be specified, and there is an effect that the processing of detecting and connecting the line break can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an image processing apparatus that performs an image line break connection process by applying an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a procedure of processing for detecting and connecting a broken line;

FIG. 3 is a plan view showing an example of a composition.

FIG. 4 is an explanatory diagram showing a configuration of run-length data.

FIG. 5 is an explanatory diagram showing another configuration of the run length data.

FIG. 6 is a view showing an image of a processing target area in the procedure of the embodiment.

FIG. 7 is a view showing an image of a processing target area in the procedure of the embodiment.

FIG. 8 is a view showing an image of a processing target area in the procedure of the embodiment.

FIG. 9 is a flowchart showing a detailed procedure of a line break automatic connection process.

FIG. 10 is a conceptual diagram showing an example of run-length data representing an image including a line break.

FIG. 11 is a diagram showing a processing target area including a line break in the main scanning line direction.

FIG. 12 is a diagram showing a processing target area including a line break in the main scanning line direction.

FIG. 13 is a diagram showing a system color table showing correspondence between system color numbers and display color numbers.

FIG. 14 is an enlarged view showing a region including a line break in the main scanning line direction.

FIG. 15 is a view showing a processing window used for the area separation processing.

FIG. 16 is an explanatory diagram showing a procedure of a region separation process.

FIG. 17 is an explanatory diagram showing a procedure of a region separation process.

FIG. 18 is an explanatory diagram showing a procedure of a region separation process.

FIG. 19 is an explanatory diagram showing a procedure of a region separation process.

FIG. 20 is a diagram showing the same system color table.

[Explanation of symbols]

 BC Underprint C Circle figure CP1, CP2 Line break Dri, Drg Run length data Drc Start point coordinate data Dsc System color data Dwb Black and white designation data d Maximum line break LNd Line drawing display color number Nd Display color number Ns System color number PR processing target area PR1, PR2 division processing area R1 to R10, R21 to R26 separation area

Claims (1)

(57) [Claims] 1. A method for connecting line breaks of a line drawing by processing image data representing a line drawing image, the method comprising: (a) selecting each image in the line drawing image displayed on the display means ;
Based on the pixel value assigned to the element,
Recognize mutually independent areas separated by boundaries
And different colors in the mutually independent areas
While assigning each area part with the assigned color
The line drawing image is displayed on the display means to form a closed area.
Compare the inner color of the power line element with the outer color and
To include line drawing elements where the color of the part and the external color are the same
In the step of designating the processing target area, (b) examining the image data representing an image of the processing target area, in the image area having a color different from the color of the line drawing portion,
Detecting a portion having a width equal to or less than a predetermined threshold value as the line break ; and (c) changing the color of the line break detected in the step (b) to the color of the line drawing portion. by modifying, missing line section connecting method characterized by and a step of connecting the wire breakage portion.