JPH05197808A - Method and device for generation of image contour line vector - Google Patents

Abstract

PURPOSE:To surely generate the contour line vector of an image in a short time without increasing the memory capacity. CONSTITUTION:The image information on an original picture is read and recorded as the original picture information consisting of the white and black picture elements. A contour extracting circuit part 8 extracts the black picture elements adjacent to the white picture elements and records them as the contour information on the original picture. A contour black picture element detecting circuit part 10 detects the black picture elements out of the contour information. An inside/outside deciding circuit part 11 decides whether the picture element group defining a black picture element part forming a contour part as an end point forms an inside or outside contour part of the original picture information. Based on this deciding result, a contour picture train tracking circuit part 12 tracks the picture element group defining a black picture element as an end point in the direction adverse to the tracking direction. Thus the contour line vector data are successively generated and stored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention extracts outline pixels of an original picture based on image information of an original picture of a handwritten figure or a printed figure recorded on a medium such as paper read by a scanner or the like. The present invention relates to a contour vector generation device for an image to be transformed into a contour vector and a contour vector generation method thereof.

[0002]

2. Description of the Related Art Conventionally, in an image contour line vector generating apparatus for reading an image of a handwritten figure or a printed figure recorded on a medium such as paper and converting the image into a contour line vector, the image is scanned by a scanner. The input image data is input, the contour portion of the image is extracted from the input image data, and contour line vector data including the black pixel at the point of interest in the contour portion is generated. Then, the difference between the respective contour line vector data is aggregated, and the difference between the respective aggregation results of the inner side contour line vector data of the image and the outer side contour line vector data is calculated, and based on the difference, the inner side of the image is calculated. It is determined which of the contour vector data is on the outer side and the outer side, and the contour pixels of the image are extracted and the contour vector is converted.

[0003]

However, in the above-described image contour line vector generation device, a contour line vector in which a certain contour line vector is followed by a contour line vector in the opposite direction in the image. The inside and outside areas cannot be determined. Therefore, there is a problem that the contour vectorization process is often impossible when the original image has many protrusions.

Further, since there are many calculation processes such as tabulation of differences in contour vector data, there is a problem that a memory having a large storage capacity is required and it takes time to process the contour vector data of an image. there were. The present invention has been made in view of the above points, and an object of the present invention is to reliably generate an outline vector of an image in a short time without increasing the memory storage capacity.

[0005]

In order to achieve the above object, the present invention provides an image reading section for reading image information of original images of a handwritten figure or a printed figure recorded on a medium by scanning input, and an image reading section thereof. An original image information recording unit for recording image information read by a unit as original image information composed of white pixels and black pixels, and a contour for extracting a black pixel adjacent to a white pixel in the original image information recorded by the original image information recording unit An extraction unit, a contour information recording unit that records the black pixels extracted by the contour extraction unit as the contour information of the original image,
A contour black pixel detection unit for reading and scanning the contour information recorded by the contour information recording unit to detect the black pixels, and a black pixel of the original image information recorded in the original image information recording unit and a contour black pixel detection unit. An inside / outside determination unit that determines which of the inner or outer contour portions the pixel group whose end points are the black pixels that form the contour portion by comparing the positions with the detected black pixels And a contour pixel string tracking unit that generates contour line vector data by tracing a pixel group having a black pixel as an end point by reversing the tracking direction depending on whether the determination result by the inside / outside determination unit is the inside side or the outside side, There is provided a contour line vector generation device for an image, which includes a contour line vector information storage unit that sequentially stores the contour line vector information generated by the contour pixel string tracking unit.

Further, the vectorization advancing direction for determining the priority of the advancing direction of vectorization in accordance with the incident direction of the tracing at each pixel of interest when generating the contour line vector data of the pixel group by the contour pixel string tracking unit. It is advisable to provide a priority table. Further, the image information of the original image of the handwritten figure or the printed figure recorded on the medium is read by scanning input, and the read image information is recorded as the original image information consisting of white pixels and black pixels. A black pixel adjacent to the pixel is extracted and recorded as contour information of the original image, the contour information is read and scanned to detect the black pixel, and the position of the black pixel and the black pixel of the recorded original image information is compared. Then, it is determined whether the pixel group whose end points are the black pixels forming the contour portion forms the contour portion on the inner side or the outer side in the original image information, and it is tracked depending on whether the determination result is the inner side or the outer side. A contour line vector generation method for an image in which the direction is reversed and a group of pixels whose end points are black pixels is traced to generate contour line vector data, and the generated contour line vector information is sequentially accumulated. To provide.

[0007]

According to the present invention, there is provided an image contour line vector generating apparatus which comprises an image reading unit, an original image information recording unit, a contour extracting unit, a contour information recording unit, a contour black pixel detecting unit, an inside / outside judging unit and a contour pixel array. By providing the tracking unit and the contour line vector information storage unit, it is not necessary to perform the complicated calculation of the vector data difference in order to generate the contour line vector of the read image. Therefore, a large storage capacity is not necessary.

Further, if a vectorization advancing direction priority table is provided so that the prioritization in the advancing direction of the vectorization of the pixel of interest is determined and the contour line vector data of the pixel group is generated, each pixel can be efficiently processed. Can be tracked. Further, if the contour line vector of the original image of the handwritten figure or the printed figure is generated by the above-described image contour line vector generation method, the contour line vector data can be efficiently generated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 2 is a block diagram showing a hardware configuration of the image outline vector generation device according to the present invention. This contour line vector generation device includes a keyboard 1 which is an input device equipped with various input keys, an image reading device 2 such as a scanner, a memory 3 which is a storage device for readable recording various information, a CRT, A display device 4 that is a display such as an LCD, a display control device 5 that controls the display of the display device 4, and a microprocessor that includes a CPU, a ROM, a RAM, and the like are incorporated to control the entire device and perform various data processing. The data processing device 6 is provided.

FIG. 1 is a block diagram showing the functions of the memory 3 and the data processing device 6 of the contour vector generating device together with the image reading device 2. The memory 3 includes an original image information recording unit 7, a contour information recording unit 9, and a contour line vector information storage unit 13.
The data processing device 6 fulfills the respective functions of the contour extraction circuit unit 8, the contour black pixel detection circuit unit 10, the inside / outside determination circuit unit 11, and the contour pixel column tracking circuit unit 12.

The image reading device 2 reads the image information of the original image of a handwritten figure or a printed figure recorded on a medium such as paper by scanning input. The original image information recording unit 7 records the image information read by the image reading device 2 as original image information including white pixels and black pixels. Contour extraction circuit unit 8
Extracts black pixels adjacent to white pixels from the original image information recorded in the original image information recording unit 7.

The contour information recording unit 9 records the black pixels extracted by the contour extraction circuit unit 8 as the contour information of the original image. The contour black pixel detection circuit unit 10 reads the contour information recorded in the contour information recording unit 9 and scans it to detect the black pixel. The inside / outside determination circuit unit 11 compares the positions of the black pixels of the original image information recorded in the original image information recording unit 7 with the positions of the black pixels detected by the contour black pixel detection circuit unit 10 to form a black pixel forming a contour portion. It is determined which of the inner side and the outer side contour portions is formed in the original image information by the pixel group whose end point is.

The contour pixel string tracking circuit unit 12 traces a group of pixels whose end points are black pixels by reversing the tracing direction depending on whether the determination result by the inside / outside determination circuit unit 11 is the inside side or the outside side and traces the contour line vector. Generate data. The contour line vector information storage unit 13 sequentially stores the contour line vector information generated by the contour pixel string tracking circuit unit 12.

Next, the processing in this contour line vector generating device will be described. FIG. 3 is a flow chart showing a process until the contour vector data of an image is recorded separately on the inner side and the outer side. First, as an input image reading process, image information of an original image of a handwritten figure or a printed figure recorded on a medium is read by scanning input by the image reading device 2, and the read image information is composed of white pixels and black pixels. Record as original image information. afterwards,
As contour extraction processing, black pixels adjacent to white pixels in the original picture information are extracted and recorded as contour information of the original picture, and the contour information is read and scanned as raster scan processing of the contour data.

Here, when a black pixel is detected from the contour information, the input pixel data corresponding to the position directly above the black pixel is detected, and the original image information recorded as the black pixel depending on whether or not it is a black pixel. And the position of the black pixel forming the contour portion as an end point forms a contour portion on the inner side or the outer side in the original image information.

Based on the determination result, the contour line vector data of interest is divided into inner side contour line vector data and outer side contour line vector data and recorded.
When black pixels are no longer detected from the contour information, the processing until the contour vector data of the image is recorded separately on the inner side and the outer side is ended. When the processing to record the contour vector data of this image separately on the inside side and the outside side is completed, the tracing direction is reversed depending on whether the judgment result is the inside side or the outside side, and the inside side contour vector By dividing the data and the outer side contour line vector data into pixel groups having black pixels as end points, the contour line vector data is generated, and the generated contour line vector information is sequentially accumulated.

Next, the contour vector generation processing will be described in more detail with reference to FIGS. FIG. 4 is a diagram showing an example of an original image recorded on a medium, and a case where a contour line vector of a figure of the original image is generated will be described. First, the image of the original graphic 14 shown in FIG. 4 is scanned in and read as binary data.

As shown in FIG. 5, pixel data consisting of white pixels and black pixels of the figure 14 is generated from the read binary data image, and the original image information of the memory 3 shown in FIG. 1 as a pixel data file. The data is recorded in the recording unit 7. FIG. 6 is an explanatory diagram showing the format of the pixel data file, and the input pixel data is obtained by regarding each pixel as 1 bit.
Recorded as hexadecimal data.

Next, the contour extraction circuit section 8 performs contour extraction processing based on the pixel data of this pixel data file. This contour extraction process is a process of paying attention to a black pixel in the pixel data, and replacing all the black pixels adjacent to the black pixel of interest with black pixels, the black pixel of interest is replaced with a white pixel.

Therefore, the pixel data shown in FIG. 5 is converted into the contour pixel data as shown in FIG. 7 by this contour extraction processing. The contour pixel data shown in FIG. 7 is recorded in the contour information recording unit 9 of the memory 3. FIG. 8 is an explanatory diagram showing the format of the contour pixel data file, and the contour pixel data is recorded as hexadecimal display data by regarding each pixel as 1 bit.

Next, the contour pixel data shown in FIG. 7 is sequentially scanned from the pixel (A, 1) in the main scanning direction of 1, 2, 3 ,. B, C,
... in the sub-scanning direction, respectively 1, 2, 3, ...
Are sequentially scanned in the main scanning direction to detect black pixels. That is, in the contour pixel data shown in FIG. 7, the pixel Do (B,
8) is detected.

After that, the contour pixel row including the pixel Do (B, 8) in FIG. 7 is a contour pixel row on the inner side of the image whose end point is the pixel Do (B, 8) in the input pixel data shown in FIG. Inside / outside determination processing is performed to determine whether there is a contour pixel row on the outside or on the outside. This inside / outside determination processing is performed by detecting the input pixel data located directly above the target black pixel data and determining whether the input pixel data is a black pixel.

For example, if the pixel Do (B, 8) is the black pixel data of interest, the pixel Da (A,
It is determined whether or not 8) is a black pixel. This determination can be made based on the presence / absence of the input pixel data shown in FIG. 6 corresponding to the contour pixel data shown in FIG. 8 corresponding to the pixel Da (A, 8) shown in FIG. 7.

Therefore, since the pixel Da (A, 8) is a white pixel, it is determined that the contour pixel row having the pixel Do (B, 8) as the end point is the contour pixel data on the outside of the image. If the pixel Da (A, 8) is a black pixel, the pixel Do (B,
Since the contour pixel row having 8) as an end point extends further upward, the pixel Do (B,
8) is deleted as the locus, and is not detected during the raster scan of the contour pixel data described above.

If the pixel Di (D, 10) in FIG. 7 is the black pixel data of interest, the pixel Db located immediately above it.
It is determined whether (C, 10) is a black pixel. Here, since the pixel Db (C, 10) is a black pixel, the pixel Di (D, 10)
It is determined that the contour pixel row having the end point is the contour pixel data on the inner side of the image. In this way, if the contour pixel row of the input pixel data is determined to be inside or outside of the image by checking the presence or absence of 1-bit data,
The process shifts to the contour vectorization processing using the 8-connected vector.

FIG. 9 is an explanatory diagram showing each direction of the 8-connected vector and each code corresponding to each direction. Vectors in 8 directions of up, down, left, right, upper right, lower right, upper left, lower left are set to 0.
It is represented by a code of ~ 7. FIG. 10 shows a case in which the target pixel on the outside and the incident direction to the target pixel are
Explanatory drawing of the vectorization advancing direction priority order table which shows the priority order at the time of connection vector generation, FIG. 11 is explanatory drawing at the time of eight connection vector generation according to the incident pixel with respect to the external target pixel and the target pixel, FIG. FIG. 12 is an explanatory diagram of a vectorized advancing direction priority order table showing priorities at the time of generating an 8-connected vector corresponding to the inside target pixel and the incident direction to the target pixel.

First, when an 8-connected vector is generated for a contour pixel column on the outer side, the contour pixel column is checked counterclockwise, and the direction of vectorization is determined by referring to the table shown in FIG. .. For example, in (a) of FIG. 10, it is shown that the presence or absence of upper right pixel data is first checked, and the check is advanced in the order of 1 to 7, and it is not necessary to check the positions indicated by X.

This is, as shown in FIG.
When checking in the counterclockwise direction at the position of the mark, the position indicated by ○ has a higher priority than the position in the direction of the arrow, so if there is pixel data at the position of ○, the outline pixel row must be marked with ○. This is because it is proceeding in the direction of the position. Therefore, the check of the direction of the position of the mark ◯ shown in FIG. 11 is not performed from the position indicated by each arrow. Also, in the case of generating an 8-connected vector for the contour pixel row on the inner side,
The contour pixel row is checked in the clockwise direction, and also in FIG.
The traveling direction of vectorization is determined by referring to the table shown in FIG.

In this way, when the 8-connected vectors are generated for the contour pixel rows on the outer side and the inner side, the contour line vector information storage unit 13 is divided into the outer side and the inner side respectively.
Remember. FIG. 13 is an explanatory diagram showing a format of a file for storing contour vector data on the external side, FIG.
FIG. 6 is an explanatory diagram showing a format of a file that stores contour vector data on the inner side.

In this embodiment, the contour line vector data on the inner side is tracked clockwise and the contour line vector data on the outer side is tracked counterclockwise. On the contrary, the contour line vector data on the inner side is counterclockwise. The contour vector data on the outer side may be tracked clockwise in the clockwise direction.

FIG. 15 briefly shows the tracking direction when the outer side of the image of the character "O" is tracked counterclockwise (in the direction of the solid line arrow) and the inner side is tracked in the clockwise direction (the direction of the broken line arrow). FIG. In addition, FIG. 16 is a diagram simply showing the tracking direction when the outer side of the image of the character "O" is tracked clockwise (in the direction of the solid arrow) and the inner side is tracked counterclockwise (in the direction of the broken arrow). It is a figure.

In this way, when the contour line vector data of the figure is generated, the inside / outside judgment of the contour line after the contour extraction can be performed by checking the presence / absence of 1-bit data. It can be done in a short time. Further, the black pixel group viewed from the contour line vector data exists on the same side on the left side or the right side with respect to the tracking direction on both the inside side and the outside side. Therefore, it is output without considering the inside side and the outside side of the figure. Offset processing can be performed on the generated contour vector data. Therefore, even if a high-resolution image reading device such as a scanner is used, vectorization of image contour data can be performed in real time for an enormous amount of data without increasing the memory storage capacity.

[0033]

As described above, according to the contour line vector generating apparatus and the contour line vector generating method according to the present invention, the contour line of the image can be surely shortened without increasing the storage capacity of the memory. Can generate vectors.

[Brief description of drawings]

FIG. 1 is a block diagram showing the functions of a memory and a data processing device of the contour vector generation device shown in FIG. 1 together with an image reading device.

FIG. 2 is a block diagram showing the configuration of an image contour line vector generation device according to the present invention.

FIG. 3 is a flowchart showing a process until the contour line vector data of an image is recorded separately on the inner side and the outer side.

FIG. 4 is a diagram showing an example of an original image recorded on a medium.

5 is an explanatory diagram showing input pixel data of the graphic of the original image of FIG. 4. FIG.

FIG. 6 is a diagram showing a format of a data file of the input pixel data.

7 is an explanatory diagram showing contour pixel data after a contour extraction process is performed based on the input pixel data of FIG.

FIG. 8 is a diagram showing a format of a data file of the contour pixel data.

FIG. 9 is an explanatory diagram showing respective directions of 8-connected vectors and respective codes corresponding to them when generating contour vector data.

FIG. 10 is an explanatory diagram of a vectorized advancing direction priority order table showing priorities at the time of generating an 8-connected vector according to a pixel of interest on the external side and an incident direction with respect to the pixel of interest.

FIG. 11 is an explanatory diagram at the time of generating an 8-connected vector according to a pixel of interest on the external side and an incident direction with respect to the pixel of interest.

FIG. 12 is an explanatory diagram of a vectorized advancing direction priority table showing priorities at the time of generating an 8-connected vector according to an internal target pixel and an incident direction with respect to the target pixel.

FIG. 13 is an explanatory diagram showing a format of a file that stores contour vector data on the external side.

FIG. 14 is an explanatory diagram showing a format of a file that stores contour vector data on the inner side.

FIG. 15 is an explanatory diagram simply showing the tracking directions when the outer side and the inner side of the image of the character “O” are tracked counterclockwise and clockwise respectively.

FIG. 16 is an explanatory view briefly showing tracking directions when the outer side and the inner side of the image of the character “O” are tracked clockwise and counterclockwise, respectively.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 keyboard 2 image reading device 3 memory 4 display device 5 display control device 6 data processing device 7 original image information recording unit 8 contour extraction circuit unit 9 contour information recording unit 10 contour black pixel detection circuit unit 11 inside / outside determination circuit unit 12 contour pixel row Tracking circuit section 13 Contour line vector information storage section 14 Original figure

Claims (3)

[Claims] 1. An image reading section for reading image information of an original image of a handwritten figure or a printed figure recorded on a medium by scanning input, and image information read by the image reading section is composed of white pixels and black pixels. An original image information recording unit for recording as original image information, a contour extraction unit for extracting a black pixel adjacent to a white pixel in the original image information recorded by the original image information recording unit, and a black pixel extracted by the contour extraction unit. A contour information recording unit for recording as contour information of the original image, a contour black pixel detecting unit for reading and scanning the contour information recorded by the contour information recording unit to detect black pixels thereof, and recording in the original image information recording unit. The pixel group whose end points are the black pixels forming the contour portion by comparing the positions of the black pixels of the original image information and the black pixels detected by the contour black pixel detection unit are the original image information. The inside / outside determination section for determining which of the inner side or the outer side contour portion is formed in the report, and the black pixel by reversing the tracking direction depending on whether the determination result by the inside / outside determination section is the inside side or the outside side. A contour pixel column tracking unit that traces a pixel group whose end points are to generate contour vector data, and a contour vector information storage unit that sequentially accumulates contour vector information generated by the contour pixel column tracking unit. An image contour line vector generation device characterized by being provided. 2. The image contour line vector generating device according to claim 1, wherein the contour pixel vector tracking unit generates contour line vector data of a pixel group in accordance with a tracking incident direction in each pixel of interest. An image contour line vector generation device, comprising a vectorization advancing direction priority table for determining the priority of advancing directions of vectorization. 3. Image information of an original image of a handwritten figure or a printed figure recorded on a medium is read by scanning input,
The read image information is recorded as original image information consisting of white pixels and black pixels, black pixels adjacent to white pixels in the original image information are extracted and recorded as outline information of the original image, and the outline information is read and scanned. Then, the black pixel is detected, and the black pixel and the position of the black pixel of the recorded original image information are compared to form a contour portion. It is determined which contour part on the side is formed, and the contour line vector data is obtained by tracing the pixel group having the black pixel as an end point by reversing the tracing direction depending on whether the determination result is the inner side or the outer side. Is generated, and the generated contour line vector information is sequentially accumulated.