JP2010109561A - Image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively avoid the decline of visibility caused when enlarging or reducing optional image data in an image processor. <P>SOLUTION: The image processor is provided with: an image data acquisition means 11 for acquiring image data relating to an optional image; a character extraction means 12 for extracting a character object from the image data; a character overlap detection means 15 for detecting the overlap between the character objects in a prescribed scale for the two or more extracted character objects; a preferential character selection means 16 for discriminating one, two or more character objects from the two or more character objects overlapping each other, on the basis of a prescribed priority reference; and an image output means 17 for outputting only the discriminated character objects together with the image data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus that avoids the problem of character display caused by reducing or enlarging image data and that outputs an image while maintaining good visibility.

In recent years, many electronic maps have been provided via recording media and the Internet instead of paper maps.
Such an electronic map can generally be scaled based on a GUI (Graphical User Interface) or the like, so that a user can easily view map data of a desired scale via an output image of a personal computer or a printer. It has become.

A general electronic map scale changing method will be described with reference to the drawings.
FIG. 6A is a diagram schematically showing a conventional method for enlarging / reducing a raster electronic map.
According to the method shown in the figure, it is theoretically possible to uniformly enlarge or reduce the map data according to an arbitrary scale ratio.
However, since raster image data (typically, a paper map read by a scanner) is formed by a collection of pixels, there is a problem in that character collapse occurs and visibility is reduced particularly during reduction. .

FIG. 6B is a diagram schematically showing a method for enlarging / reducing vector-format map data used in a car navigation system or the like.
Character information included in such image data in vector format includes character display information at the time of enlargement or reduction (character string display position, font, font size, thickness, color, etc.) Etc. will not occur.
However, since it is necessary to set such character display information in advance, there has been a problem in that a lot of time and labor are required for preparation.

FIG. 6C is a diagram schematically illustrating a method for enlarging / reducing an electronic map using raster / vector conversion.
In the method shown in the figure, raster / vector conversion (hereinafter referred to as “Lasbek conversion”) is performed on map data in raster format, and vector data of character information and vector data other than character information are uniformly expanded or reduced. How to do it.
The map data in the vector format obtained by the Rasbek transformation can be logically enlarged or reduced uniformly.
However, since the map data acquired by the Rasbek conversion does not include character display information at the time of enlargement or reduction, there is a problem that character collapse may occur if the image data is reduced as it is.

Furthermore, a so-called electronic map reduction method using character-accompanying information is shown in FIGS.
FIGS. 7A to 7C are diagrams schematically showing a method for reducing an electronic map having character information to which character supplementary information is attached.
The character supplementary information is, for example, setting information in which a minimum size of characters at the time of reduction, a displayable range on a character graphic, and the like are set in advance, and is data in a format attached to character information.
As shown in the figure, in this method, character supplementary information is assigned to character information in the vector format. Therefore, even if the entire map is uniformly reduced, character collapse or the like does not occur.

However, the character supplementary information needs to be set in a one-to-one correspondence for each map data having a different scale or display range.
For example, the display area (scale, position, etc.) occupies a different character string indicating the same “Tokyo” on a map of the Kanto region and a map of Japan. It is necessary to create character supplementary information for each different map and set it for each character information.
For this reason, the amount of data necessary for setting the character supplementary information has become enormous, making it extremely difficult to implement.

For such a problem, various techniques for improving the visibility when the scale is changed have been proposed (see, for example, Patent Documents 1 and 2).
Patent Document 1 discloses a character string display method for improving visibility by rearranging an unreadable character string in a display area by clipping or reduction.
Further, Patent Document 2 discloses a name display device in the figure that preliminarily sets a character string display permission condition according to enlargement or reduction, and displays only a character string having a necessary name on a figure in accordance with the condition. It has been done.

Japanese Patent No. 2916347 JP-A-5-61405

However, according to the character string display method described in Patent Document 1, when the character size of the overlapping character string is less than a predetermined value, the character string is enlarged and rearranged within the allowable range of the arrangement possible range. However, since there is a limit to the possible arrangement range, it is impossible to completely avoid overlapping characters.
In addition, according to the name display device in the drawing described in Patent Document 2, it is necessary to set display permission / prohibition conditions for all character strings, and therefore it is necessary to set a huge amount of conditions depending on the size of the display range. Is extremely difficult to achieve.
That is, visibility cannot be suitably maintained by conventional techniques related to scale change, including Patent Document 1 and Patent Document 2, which has been a problem.

  The present invention has been proposed in order to solve the problems of the conventional techniques as described above, and image processing that effectively avoids a decrease in visibility that occurs when any image data is enlarged or reduced. The purpose is to provide a device.

  In order to achieve the above object, an image processing apparatus of the present invention includes an image data acquisition unit that acquires image data relating to an arbitrary image, a character extraction unit that extracts a character object from the image data, and two or more extracted characters. With regard to objects, character duplication detection means for detecting duplication between character objects at a predetermined scale, and one or two or more character objects are selected from two or more character objects overlapping each other based on a predetermined priority standard Priority character selection means, and image output means for outputting only the selected character object together with the image data.

  According to the image processing apparatus of the present invention, it is possible to freely change the scale while maintaining good image visibility regardless of the format of the target image data.

A preferred embodiment of the present invention will be described below with reference to FIGS.
Here, the image processing apparatus 1 of the present embodiment described below is realized by processes, means, and functions executed by a computer in accordance with instructions of a program (software). The program sends a command to each component of the computer to perform predetermined processing and functions as shown below. That is, each process / means in the image processing apparatus 1 of the present embodiment is realized by specific means in which a program and a computer cooperate.
Note that all or part of the program is provided by, for example, a magnetic disk, optical disk, semiconductor memory, or any other computer-readable recording medium, and the program read from the recording medium is installed in the computer and executed. The The program can also be loaded and executed directly on a computer through a communication line without using a recording medium.

FIG. 1 is a functional block diagram showing a configuration of an image processing apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the image processing apparatus 1 according to this embodiment includes an image data acquisition unit 11, a character extraction unit 12, a scale input unit 13, a scale change unit 14, a character duplication detection unit 15, and a priority character selection unit 16. , Image output means 17, priority reference registration means 18, editing means 19, and character position calculation means 20.

The image data acquisition unit 11 is a unit that acquires image data relating to an arbitrary image. For example, a scan mechanism such as an image scanner corresponds to this.
In this embodiment, it is assumed that the image data acquisition unit 11 acquires raster-format map data (electronic map) by scanning a paper map.
However, the target image data is not limited to raster format map data, and may be, for example, vector format map data.

The character extraction unit 12 extracts a character object from the image data acquired by the image data acquisition unit 11.
Specifically, only character objects are extracted by OCR (Optical Character Reader). As a result, the original image data is divided into character objects (vector data) and image data (raster data) other than character objects. To be separated.
The character extraction unit 12 also extracts attribute data of the character object.
Specifically, data such as character string information, display position, font, font size, thickness, and color regarding the character object is extracted and used for priority character determination described later.

The scale input means 13 is for inputting a scale for outputting image data in accordance with a predetermined operation and a character object identifiable scale (“predetermined scale” in the present invention). The user can set a desired enlargement ratio or reduction ratio (scale) and a limit of the reduction ratio of character objects (identifiable scale) via an input device such as a liquid crystal panel.
In this embodiment, since the map is assumed to be reduced, the user can set a reduction rate such as 80% or 50% or an identifiable scale via the scale input means 13.
It is also possible to change the current scale (for example, 1/10000) to another scale (for example, 1/50000).

In principle, the scale changing unit 14 enlarges or reduces the image data in accordance with the scale input by the scale input unit 13.
In particular, in the present embodiment, the character object selected by the priority character selection unit 16 to be described later is formed in accordance with an arbitrary scale with the identifiable scale input from the scale input unit 13 as a limit, and the image data is generated. It is characterized by being formed according to an arbitrary scale.

The character duplication detection means 15 detects duplication of character objects at the “predetermined scale”.
Specifically, based on the position data (coordinate values, etc.) of each character object calculated by the character position calculation means 20 of this embodiment, the character position when enlarged or reduced to a “predetermined scale” is calculated. To determine the overlap of characters.
In particular, when the reduction is performed, the “predetermined scale” is set to a scale within a range up to the minimum size where character collapse does not occur.
In other words, the present invention is realized rationally and simply by eliminating the possibility of character crushing in advance and detecting overlapping characters.

The priority character selection means 16 selects one or two or more character objects from two or more character objects that overlap each other based on a predetermined priority criterion.
That is, it is a means for selecting only character objects with high priority to be output from among overlapping character objects.
Note that priority criteria necessary for selecting priority characters will be described later.

The image output means 17 outputs only the character object selected by the priority character selection means 16 together with the image data.
Specifically, the character object selected by the priority character selection means 16 and image data other than the character object are enlarged / reduced, further combined, and then printed via the printing mechanism.
For this reason, since character objects that are not selected by the priority character selection means 16 are not output, it is possible to avoid overlapping characters.
The image output means 17 outputs both the image data enlarged or reduced by the scale change means 14 and the character object.
That is, as for the character object, an object that has been enlarged or reduced within an identifiable range is output, thereby maintaining the visibility.

The priority standard registration means 18 is for registering a priority standard based on predetermined character priority information, and executes the priority character selection means 16 based on this priority standard.
The character priority information is, for example, a definition file composed of attribute data such as font size, thickness, color, character string, and display position of a character. These are stored in advance in storage means (not shown).

Here, priority criteria based on the character priority information will be described in detail with reference to FIG.
FIG. 2 is a priority information table for explaining character priority information and priority criteria used for selection of priority characters.
As shown in FIG. 2, character attribute data of various categories are registered as character priority information. Further, in the same figure, the higher category has a higher priority, and even the same category has a higher priority on the left side. It shows a certain priority standard that is high.
As a premise, it is assumed that duplication of character objects has been detected by the character duplication detection means 15.

Therefore, the priority character selection means 16 first performs priority determination regarding the font size of the duplicate character based on the extracted attribute data of the character object.
For example, based on the priority criteria of FIG. 2, if the font size of overlapping characters is different, the character with the larger font size is selected with priority.
Next, if the font sizes are the same, the priority character selection unit 16 determines the thickness of the character and preferentially selects the thicker character.
Similarly, if the thickness of the character is the same, the priority character selection means 16 next determines the character color and selects the priority character in the order of red, blue, black, and other colors.
Furthermore, if the character colors are the same, the priority character selection means 16 performs priority determination for a predetermined character string as shown below.
That is, in this embodiment, the priority order is determined in the order of “National highway”, “Railway”, “Station”, “Office”, “University”, “High school”, “Junior high school”, “Primary school”. If there is a character including this character string, the priority character is determined based on the priority order.

Therefore, priority determination based on character priority information regarding a character string will be described with reference to FIG.
FIG. 3 is an explanatory diagram for explaining character string priority determination executed by the priority character selection unit according to the present embodiment.
As shown in FIG. 3A, in the original image before the scale change, “National highway No. XX” and “ΔΔ station” are displayed separately on the map. At this stage, both characters are displayed. Can be clearly identified.
If this is reduced by a considerable scale (for example, 50%), as shown in FIG. 3B, a part of “National highway No. XX” and “ΔΔ station” overlap and become characters that are difficult to identify.
Therefore, in the present embodiment, according to the priority order as shown in FIG. 2, when a character object including “National road” and a character object including “Station” overlap, the character including “National road” is given priority. The characters including “station” are excluded from the output target.
As a result, as shown in FIG. 3C, a desired scale can be changed while ensuring a certain level of visibility.

Returning to FIG. 2, a specific character string (for example, “ABC building”) may be arbitrarily registered as the character priority information, and may be added to the character string determination as described above.
It is desirable to set default character priority information in advance in consideration of the case where priority determination is impossible even with the above character priority information.
For example, as shown in the lowermost part of FIG. 2, by performing character priority determination based on the character display position, reliable character priority determination is possible, and stable operation of the apparatus based on a smooth algorithm can be ensured. .

Returning to FIG. 1, the editing means 19 is a means for changing a definition file made up of character priority information and priority criteria registered in accordance with an input operation, and can be rewritten by the user.
Therefore, the character priority information related to the character string may be used as the highest priority priority reference, and other character priority information not shown in FIG. 2 may be added.

The character position calculation means 20 calculates the display position on the display area at a predetermined scale of two or more character objects extracted by the character extraction means 12.
Based on the display position calculated here, the character duplication detection means 15 determines the duplication of character objects.

Next, an image processing procedure of the image processing apparatus 1 according to the present embodiment will be described in detail with reference to the drawings.
FIG. 4 is a flowchart showing a procedure of image processing in the image processing apparatus according to the present embodiment.
As shown in the figure, first, the image data acquisition means 11 such as a scanner reads a target paper map (S201).
As a result, the image processing apparatus 1 acquires an electronic map (raster data) based on a paper map.
Next, the OCR (Optical Character Reader), that is, the character extracting means 12 of this embodiment extracts a character object from the electronic map (S202).
Specifically, through this process, the electronic map data is separated into character information (vector data) and data other than character information (raster data).

Therefore, according to the scale input from the scale input means 13, the scale changing means 14 uniformly enlarges / reduces data other than character information (raster data) (S203).
On the other hand, the scale changing means 14 enlarges or reduces the character information (vector data) based on the identifiable scale (S204).
Specifically, the enlargement / reduction is performed at a scale limit that allows the character to be identified (character collapse does not occur).
For example, if the user wants to reduce the entire electronic map by 50%, and if the target character object is reduced to 50% and character collapse occurs, the maximum scale at which character collapse does not occur (for example, 80%) Thus, the character object is reduced, and image data other than the character object is reduced by 50%.

Next, the character duplication detection means 15 determines whether or not the display areas of a plurality of character objects overlap each other, and detects any corresponding character objects (S205).
As a result of S205, when the character overlap detection means 15 does not detect the overlap of characters (S205: NO), all the extracted character objects are determined as display characters (S206).
On the other hand, as a result of S205, when the character duplication detection unit 15 detects the overlap of characters (S205: YES), after the priority character selection unit 16 selects a display character based on the character priority information and the priority standard (S207), The selected character is determined as a display character (S206).

Subsequently, the image processing apparatus 1 synthesizes image data (map data) other than the character information enlarged or reduced by the scale changing unit 14 and display characters (S208).
And the image output means 17 outputs the electronic map synthesize | combined in step S208 as a paper map.

Here, the priority character selection method based on the character priority information (display character creation in S207) will be described in detail with reference to FIGS.
FIG. 5 is a flowchart showing an output character selection method based on the character priority information shown in FIG.

As shown in FIG. 5, when the duplication of character objects is detected, the priority character selection unit 16 first determines whether or not the font sizes of the target character objects match (S401).
If it is determined in step S401 that the font sizes do not match (S401: NO), the priority character selection unit 16 determines that the character object with the larger font size is valid and selects it (S402).
On the other hand, if it is determined in step S401 that the font sizes match (S401: YES), the priority character selection unit 16 then determines whether the thicknesses of the characters match (S403).

As a result of step S403, when it is determined that the thickness of each character does not match (S403: NO), the priority character selection means 16 determines that the thicker character object is valid and selects it (S404).
On the other hand, if it is determined in step S403 that the character thicknesses match (S403: YES), the priority character selection unit 16 next determines whether the colors of the characters match (S405). .

If it is determined in step S405 that the character colors do not match (S405: NO), the priority character selection unit 16 determines that the character object having a predetermined color having a high priority is valid and selects it (S406). ).
In the case of this embodiment, as shown in FIG. 2, priority is set such that red is given the highest priority, followed by blue, yellow, black, and other colors. For example, one of the overlapping characters is red. When the other is yellow, the red character object is selected by the priority character selection means 16.

If it is determined in step S405 that the character colors match (S405: YES), then the priority character selection unit 16 determines whether there is a character object that matches the “other predetermined condition”. (S407).
In the present embodiment, character priority information related to a character string is set as “another predetermined condition”.
Specifically, as shown in FIG. 2, “National highway” is given the highest priority, followed by “railway”, “government office”, “university”, “high school”, “junior high school”, “primary school”. Is set.
According to this priority, for example, when “National highway 20” (having priority of national highway) and “Shinjuku station” (having priority of “railway”) overlap, “national highway 20” Will be given priority.

If the result of step S407 matches the “other predetermined condition” (S407: YES), the priority character selection means 16 determines that the character object that matches the “other predetermined condition” is valid and selects it (S408).
On the other hand, as a result of step S407, when it is determined that the “other predetermined condition” is not satisfied (S407: NO), it is determined whether or not the “user-specified condition” is satisfied (S409).
In this embodiment, character priority information related to a specific character string is set as the “user specified condition”. For example, as shown in FIG. 2, character priority information is added to a specific character string such as “ABC building”. Can be set.

If the result of step S409 matches the “user specified condition” (S409: YES), the priority character selection means 16 selects the character that matches the “user specified condition” as valid (S410).
In the present embodiment, when the specific character string shown in FIG. 2 is detected, the priority character selection unit 16 selects a character object including the specific character string.

On the other hand, if the result of S409 does not match the “user specified condition” (S409: NO), then the priority character selection means 16 determines the output character based on the “default priority condition” (S411). ).
As a “default priority condition” in the present embodiment, a condition for selecting an output character based on the character arrangement is set.
Specifically, as shown in the lowermost part of FIG. 2, the priorities are determined in the order of left, right, upper, and lower, and a character object is selected according to the determination.

As described above, according to the image processing apparatus 1 of the present embodiment, the character extraction unit 12 can extract character data from arbitrary image data, and acts to separate a character object from map data. Have.
In addition, when the character duplication detection unit 15 determines the duplication of character objects at a predetermined scale and detects such duplication, the priority character selection unit 16 has a higher priority among the duplicated characters. The character is selected.
Then, the image output means 17 outputs only the high priority characters together with the image data.

In particular, the scale changing means 14 enlarges / reduces the character with respect to the scale rate that can be identified when the user arbitrarily changes the scale, and the character duplication detection means 15 performs the character overlap within that range. The overlap is determined.
For this reason, it is possible to avoid deterioration in visibility such as overlapping of characters and collapsed characters that occur particularly at the time of reduction, and it is possible to ensure good visibility at any scale change.

Further, the priority character selection means 16 selects an output character based on the definition file registered by the priority reference registration means 18.
The definition file is formed on the basis of simple logic based on character priority information composed of character attribute data and priority criteria indicating the priority order of the character priority information.
The contents of these definition files can be added, deleted, rearranged, etc., as desired by the user via the editing means 19.

For this reason, according to the image processing apparatus 1 of the present invention, the scale can be freely changed while maintaining good visibility of any image regardless of the format of the target image data.
Therefore, it has high convenience and also realizes applicability and expandability that can be adapted to various usage modes.
In addition, the scale change processing, character duplication determination, and priority character determination, which are important for carrying out the present invention, are rationally configured, and necessary equipment and programs can be realized easily and inexpensively. It is possible to provide an image processing apparatus 1 having a high level.

As described above, the image processing apparatus 1 of the present invention has been described with reference to the preferred embodiment. However, the image processing apparatus 1 according to the present invention is not limited to the above-described embodiment, and variously within the scope of the present invention. Needless to say, it is possible to implement this change.
For example, the image processing apparatus 1 of the present invention has been mainly described with respect to a case of reducing a map, but can be applied even when the map is enlarged.
In this case, the map is enlarged according to the scale designated by the scale changing means 14, but visibility is improved by restricting the enlargement ratio so that at least characters are enlarged within a range where no blur occurs. Can be maintained.
In the above embodiment, the identifiable scale is input from the scale input unit 13, but may be set in the image processing apparatus 1 in advance.
Moreover, not only a map but various drawings, such as a mechanical drawing and an architectural drawing, can also be targeted.

  The present invention can be suitably used for an image processing apparatus including a scanner and an OCR.

1 is a functional block diagram illustrating a configuration of an image processing apparatus according to an embodiment of the present invention. FIG. 5 is a priority information table for explaining character priority information and priority criteria used for priority character selection according to an embodiment of the present invention. It is explanatory drawing for demonstrating the priority determination of the character string performed in the priority character selection means which concerns on this embodiment. 6 is a flowchart illustrating a procedure of image processing in the image processing apparatus according to the embodiment of the present invention. 3 is a flowchart showing an output character selection method based on the character priority information shown in FIG. It is the figure which showed typically the conventional method which expands or reduces the electronic map of a raster format or a vector format. It is the figure which showed typically the method of reducing the electronic map which has the character information to which the character supplementary information was attached | subjected.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image processing apparatus 11 Image data acquisition means 12 Character extraction means 13 Scale input means 14 Scale change means 15 Character duplication detection means 16 Priority character selection means 17 Image output means 18 Priority reference registration means 19 Editing means 20 Character position calculation means

Claims (12)

Image data acquisition means for acquiring image data relating to an arbitrary image;
Character extraction means for extracting a character object from the image data;
Character duplication detection means for detecting duplication between character objects at a predetermined scale with respect to two or more extracted character objects,
Priority character selection means for selecting one or more character objects from two or more character objects overlapping with each other based on a predetermined priority criterion;
Image output means for outputting only the selected character object together with the image data;
An image processing apparatus comprising: The predetermined scale is:
The image processing apparatus according to claim 1, wherein the scale is a predetermined scale set within a range in which the character object can be identified. Scale input means for inputting an arbitrary scale based on a predetermined operation;
Scale change means for forming the character object selected by the priority character selection means according to the arbitrary scale with the predetermined scale as a limit, and forming the image data according to the arbitrary scale; Prepared,
The image output means includes
The image processing apparatus according to claim 1, wherein the image data and the character object formed by the scale changing unit are output.   The image processing apparatus according to claim 3, wherein the scale input unit inputs the predetermined scale based on a predetermined operation.   The image processing apparatus according to claim 1, wherein the character extraction unit extracts a character object from the image data and extracts attribute data related to the character object.   6. The image processing apparatus according to claim 1, further comprising priority reference registration means for registering the priority reference based on predetermined character priority information.   The image processing apparatus according to claim 6, further comprising an editing unit that changes the character priority information and / or the priority reference according to an input operation. The priority criteria is
The image processing apparatus according to claim 6 or 7, wherein a priority order of character priority information belonging to one category and character priority information belonging to another category is predetermined. The priority criteria is
The image processing apparatus according to any one of claims 6 to 8, wherein a predetermined priority order is predetermined for two or more character priority standards belonging to the same category.   The image processing apparatus according to claim 6, wherein the character priority information is attribute data related to a character object. The attribute data is
The image processing apparatus according to claim 5 or 10, comprising at least one of a font size, thickness, color, character string information, and display position of a character object. Character position calculation means for calculating a display position after output at the predetermined scale of two or more character objects extracted by the character extraction means,
The character duplication detection means includes:
The image processing apparatus according to claim 1, wherein an overlap between the character objects is detected based on the calculated display position.

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