JP2011151703A - Image processing apparatus, character magnification processing method and character magnification program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently magnify a character included in a document image efficiently in a short processing time without disordering appearance of a document when magnifying the character. <P>SOLUTION: An image processing apparatus includes: a character region extracting section 32 which extracts a character region by the unit of a row from an inputted document image D1; a character block forming section 33 which compares each character region with another character region positioned in the vicinity of the each character region to perform grouping for each of one or multiple character regions having at least the same character attribute, and thereby forms a rectangular character block including the character regions included in each group; a magnification frame setting section 36 which sets, for each character block, a magnification frame including the character block and including a margin region around the character block, and sets each magnification frame so as to become approximately maximum within a range without interference with another magnification frame; and a magnification processing section 37 which magnifies the character block included in each magnification frame so as to be settled within the range of each magnification frame. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, a character enlargement processing method, and a character enlargement program, and more particularly to a technique for performing enlargement processing of characters included in a document image.

  2. Description of the Related Art Conventionally, various techniques for enlarging and outputting characters included in a character area when a document image including characters is printed out by a printer or the like have been proposed (for example, Patent Documents 1 and 2). By enlarging and outputting characters at the time of print output, even a user who is difficult to read small characters due to presbyopia or amblyopia, for example, can easily read the text.

  For example, Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for determining a character area and a non-character area included in a document image, separating the character area from the document image, and performing an enlargement process. That is, a process for detecting the character size of the character area separated from the document image, centering the character area, and then enlarging the characters in the character area so that the character area after the centering process does not exceed the area other than the character area Is done. Then, the image data of the character area including the enlarged character and the image data of the non-character area are re-layed and combined to generate image data for printing.

  Patent Document 2 discloses a technique for enlarging small characters included in a character area using a blank area around the character area in a document image having a character area, a non-character area, and a blank area. ing. In this technique, when a character is enlarged using line spacing, a small character included in the character region is enlarged while maintaining the center position of the line. In addition, when enlarging a character using a blank area around the character area, the non-character area is reduced or moved to expand the blank area, and the expanded blank area is used to enlarge the character. ing.

JP-A-2005-223824 JP 2008-177823 A

  However, the conventional technique has a problem that it takes a long time to enlarge characters included in a document image. For example, in Patent Document 1, since the character area is centered within a predetermined area, it takes time to calculate the center position of the character area or the center position of the area to be centered. In addition, after enlarging the characters included in the character area, it takes time to synthesize the character area and the non-character area. In Patent Document 2, it takes time to calculate the center position of a line and to reduce or move a non-character area. Also in the technique of Patent Document 2, since the process of rearranging the character area and the non-character area is performed after enlarging the character, this process takes time. Further, in Patent Document 2, since the character enlargement process is performed in units of lines, if the number of lines included in the document image increases, the processing time increases accordingly. As described above, the technique described above cannot efficiently enlarge characters.

  Further, in Patent Document 1, the character area and the non-character area may overlap even if the character area and the non-character area are combined after enlarging the character, and the layout of the original document image is corrupted. There is also a problem that it ends up. Also, as in Patent Document 2, if the character enlargement process is performed in units of lines, it may be enlarged at different enlargement ratios for each line. For example, a sentence composed of a plurality of lines may have different character sizes for each line. It may become difficult to read the text.

  In addition, general document images often include non-significant character strings such as headers and footers, and if such character strings are enlarged, the appearance of the document is destroyed. There is a possibility that. In addition, a character string such as a title included in a document has a large character size that is easier to read than other character strings at the time the document is created, and there is often no need to perform enlargement processing. However, in the above conventional technique, such a character string is processed in the same manner as other character strings, so that there is a problem that the characters are enlarged and the appearance of the document is lost.

  Therefore, the present invention has been made to solve the above-described conventional problems, and compared with the conventional technique, the character of the document is not destroyed, and the characters can be efficiently expanded in a short processing time. An object is to provide an image processing apparatus, a character enlargement processing method, and a character enlargement program.

  In order to achieve the above object, an invention according to claim 1 is an image processing apparatus, wherein a character area extracting means for extracting a character area line by line from a document image having a character area and a margin area, and the character By comparing each character area in units of lines extracted by the area extracting means with other character areas located in the vicinity thereof, it is grouped into one or a plurality of character areas having at least the same character attribute, For each character block formed by the character block forming means for forming a rectangular character block containing the included character area, the margin area extracting means for extracting the margin area of the document image, and the character block forming means, Set an enlargement frame that includes a character block and includes a blank area around the character block, and each enlargement frame does not interfere with other enlargement frames Enlarging frame setting means for setting the frame to be substantially maximum, and enlargement processing means for enlarging the character block included in each enlarging frame so as to be within the range of each enlarging frame. It is a configuration.

  According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the character attribute is a font type or a character size.

  According to a third aspect of the present invention, in the image processing apparatus according to the first or second aspect, the character block forming means includes a plurality of character areas having the same character attribute and having the same line spacing. It is the structure characterized by grouping into these groups.

  According to a fourth aspect of the present invention, in the image processing apparatus according to any one of the first to third aspects, the enlargement processing unit determines an enlargement rate of the character block when enlarging the character block. The image forming apparatus further includes a determining unit, wherein the enlargement rate determining unit determines a maximum enlargement rate that falls within the range of the enlargement frame.

  According to a fifth aspect of the present invention, in the image processing apparatus according to the fourth aspect, the enlargement ratio determining means is arranged so that the character size included in the character block does not exceed the maximum character size existing in the document image. In addition, the enlargement ratio of the character block is determined.

  According to a sixth aspect of the present invention, in the image processing apparatus according to any one of the first to fifth aspects, the enlargement processing means further includes an enlargement determination means for determining whether or not to enlarge the character block. The enlargement determination means is configured to exclude a character block that is at the uppermost position or the lowermost position of the document image and has a smaller block size than other character blocks from the enlargement target.

  According to a seventh aspect of the present invention, in the image processing apparatus according to any one of the first to fifth aspects, the enlargement processing means further includes an enlargement determination means for determining whether or not to enlarge the character block, The enlargement determination unit is configured to exclude a character block including a maximum character size from character sizes existing in the document image from an enlargement target.

  The invention according to claim 8 is a character enlargement processing method, comprising: extracting a character area line by line from a document image having a character area and a blank area; and extracting each character area extracted line by line. By comparing with other character areas located in the vicinity thereof, one or a plurality of character areas having at least the same character attribute are grouped to form a rectangular character block containing the character areas included in each group. A step of extracting a margin area of the document image; and for each character block, setting an enlargement frame that includes the character block and includes a margin area around the character block; A step of setting the maximum size within a range that does not interfere with other enlarged frames and a character block included in each enlarged frame are expanded so as to be within the range of each enlarged frame. A structure characterized in that it comprises the steps of, a.

  The invention according to claim 9 is a character enlargement program comprising: a character area extracting unit that extracts a character area line by line from a document image having a character area and a blank area; and the character area extracting unit. By comparing each character area extracted in units of lines with other character areas located in the vicinity, the character areas are grouped into one or more character areas having at least the same character attributes, and are included in each group. A character block forming means for forming a rectangular character block that includes the character block, a blank area extracting means for extracting a blank area of the document image, and for each character block formed by the character block forming means, In addition, an enlargement frame including a margin area around the character block is set, and each enlargement frame does not interfere with other enlargement frames. A configuration characterized by functioning as an enlargement frame setting unit that is set to be substantially maximum, and an enlargement processing unit that enlarges a character block included in each enlargement frame to be within the range of each enlargement frame It is.

  According to the present invention, since enlargement processing is performed for each character block including one or a plurality of character regions having at least the same character attribute, the character of the document is not destroyed and the characters can be efficiently processed in a short processing time. Can be expanded.

1 is a diagram illustrating a configuration example of an image processing system. It is a block diagram which shows an example of the hardware constitutions of a computer. It is a block diagram which shows an example of a function structure of the control part implement | achieved when CPU runs a character expansion program. It is a figure which shows an example of the document image used as the expansion object of a character. It is a figure which shows an example of the character area of the line unit extracted by the character area extraction part. It is a figure which shows an example of the character block formed by the character block formation part. It is a figure which shows an example of the available margin range set by the margin area extraction part. It is a figure which shows an example of the expansion frame set with respect to each character block by the expansion frame setting part. It is a figure which shows an example of the printable range detected by the expansion frame setting part. It is a figure which shows an example of the enlarged frame expanded to the printable range by the enlarged frame setting part. It is a figure which shows an example of the document image after the expansion determination process by the expansion determination part was performed. It is a figure which shows the document image after an enlargement process was performed by the enlargement execution part. It is a flowchart which shows an example of the detailed process sequence of the character expansion process for expanding the character contained in a document image.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments described below, members that are common to each other are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

  FIG. 1 is a diagram illustrating a configuration example of an image processing system according to the present embodiment. In this image processing system, a computer 1 constituted by a general personal computer (PC) or the like and an image forming apparatus 2 having a printer function and the like are connected to each other via a network 3 so as to be able to perform data communication with each other. It is a configuration. The network 3 is a network such as a LAN, but may be a simple cable that directly connects the computer 1 and the image forming apparatus 2.

  The computer 1 generates a document image based on an editing operation by a user. The computer 1 can also input a document image from the outside. Then, the computer 1 outputs those document images to the image forming apparatus 2 via the network 3. The image forming apparatus 2 forms an image on a predetermined print medium such as a print sheet based on a document image input from the computer 1 and performs print output. The image forming apparatus 2 may be a printing apparatus having only a printer function, or an MFP (Multi Function Peripheral) having a plurality of functions such as a copy function, a FAX function, and a scanner function in addition to the printer function. It may be.

  In the present embodiment, when the computer 1 outputs a document image to the image forming apparatus 2 in the configuration as described above, characters included in the document image can be enlarged and output. By outputting a document image in which characters are enlarged from the computer 1, the document image printed out by the image forming apparatus 2 is a user who is difficult to read small characters due to presbyopia or amblyopia. The document image can be easily read. That is, in the present embodiment, the computer 1 functions as an image processing apparatus that performs character enlargement processing.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the computer 1. As shown in FIG. 2, the computer 1 includes a control unit 10, a network interface 13, a display unit 14, an operation unit 15, and a storage device 16, and these are mutually connected via a data bus 20. It is a configuration that can input and output. The control unit 10 includes a CPU 11 and a memory 12, and functions as various processing units when the CPU 11 reads out and executes various programs stored in the storage device 16. The memory 12 stores temporary data associated with the CPU 11 executing a program. The network interface 13 is for connecting the computer 1 to the network 3. The display unit 14 is for displaying various information to the user who uses the computer 1. The operation unit 15 includes, for example, a keyboard and a mouse, and receives an input operation from a user who uses the computer 1. The storage device 16 is a nonvolatile storage unit configured with a hard disk device or the like.

  A printer driver 17 and a document creation application program 19 are installed in the storage device 16 in advance. The printer driver 17 is a program for the computer 1 to output a document image for printing to the image forming apparatus 2. The printer driver 17 incorporates a character enlargement program 18 that causes the computer 1 to perform a process of enlarging characters included in the document image. The document creation application program 19 is a program for creating and editing a document image in the computer 1.

  When a user using the computer 1 instructs to create or edit a document image by operating the operation unit 15, the CPU 11 reads and executes the document creation application program 19. A document image is generated based on a user editing operation input via the operation unit 15. Such a document image is composed of a character area consisting only of characters, a non-character area where images other than characters are arranged, and a blank area excluding the character area and the non-character area. The document image may not include a non-character area. In this case, the document image is composed of a character area and a blank area.

  When a user using the computer 1 gives an instruction to print a document image as described above by operating the operation unit 15, the CPU 11 reads and executes the printer driver 17. When the CPU 11 executes the printer driver 17, the CPU 11 displays a setting operation screen for outputting a document image to the image forming apparatus 2 on the display unit 14 and accepts a setting operation input by the user via the operation unit 15. . When the user instructs execution of enlargement processing of characters included in the document image, the CPU 11 reads out and executes the character enlargement program 18 incorporated in the printer driver 17, thereby expanding the characters included in the document image. Execute.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the control unit 10 realized by the CPU 11 executing the character enlargement program 18. As shown in FIG. 3, the control unit 10 includes a document image acquisition unit 31, a character region extraction unit 32, a character block formation unit 33, a blank region extraction unit 34, a non-character region extraction unit 35, an enlarged frame setting unit 36, and It functions as the enlargement processing unit 37. The enlargement processing unit 37 includes an enlargement determination unit 37a, an enlargement rate determination unit 37b, and an enlargement execution unit 37c. The control unit 10 is configured to generate and output a document image D2 in which only the characters included in the input document image D1 are enlarged by causing these units to function sequentially or in parallel.

  The document image acquisition unit 31 is a processing unit that acquires a document image D1 to be enlarged. For example, when the character enlargement program 18 is executed by the CPU 11, the document image acquisition unit 31 acquires the document image D <b> 1 that is a character enlargement target from the printer driver 17.

  FIG. 4 is a diagram illustrating an example of a document image D1 to be enlarged. The document image acquisition unit 31 acquires a document image D1 as shown in FIG. 4, for example. Note that the overall size of the document image D1 corresponds to the paper size at the time of print output. The document image D1 includes character areas 41 arranged at a plurality of locations and non-character areas 42 such as images arranged at a slightly lower right position in the center of the document image D1. Also, all blank portions that do not correspond to either the character region 41 or the non-character region 42 are blank regions 43. Therefore, the document image D1 shown in FIG. 4 includes a character area 41, a non-character area 42, and a blank area 43.

  The character region extraction unit 32 is a processing unit that extracts the character region 41 line by line from the document image D1 acquired by the document image acquisition unit 31. Note that a known method may be employed as a specific method for extracting the character region 41 in units of lines in the character region extraction unit 32. The character region extraction unit 32 extracts a character string included in each of the character regions 41 from the document image D1 including the character region 41, the non-character region 42, and the blank region 43 in units of lines.

  FIG. 5 is a diagram illustrating an example of a character area in units of lines extracted by the character area extraction unit 32. Since the document image D1 includes a plurality of lines of character strings, when the character string is extracted in units of lines by the document image acquisition unit 31, a plurality of character areas 51 to 51 are extracted from the document image D1 as shown in FIG. 61 is obtained. That is, each of the plurality of character areas 51 to 61 is composed of a character string of one line. As described above, the character region extraction unit 32 extracts the character regions 51 to 61 in units of lines from the document image D1 acquired by the document image acquisition unit 31.

  The character block forming unit 33 is a processing unit that forms a character block by grouping a plurality of character regions 51 to 61 extracted in line units by the character region extracting unit 32. That is, the character block forming unit 33 converts each of the plurality of character regions 51 to 61 extracted by the character region extracting unit 32 to other character regions (in the case of FIG. Compare with (character area). At this time, it is compared whether or not the character attribute of the character included in one character region is the same as the character attribute of the character included in another character region. Here, the character attributes include font type and character size. Then, the character block forming unit 33 performs grouping by combining one or a plurality of character regions that are located in the vicinity of each other and have the same character attribute. At this time, if the character attributes of a character included in a certain character area are different from the character attributes of other character areas located near the upper and lower sides of the character area, the one character area becomes a group by itself. In addition, when a plurality of character areas having the same character attribute are continuously arranged, the plurality of character areas are combined into one group. By performing such grouping, one or a plurality of character areas having the same notation form one group, and at least one group is generated from the document image D1.

  Further, when the character block forming unit 33 compares the character areas in order to group the plurality of character areas 51 to 61, the distance between one character area and another character area (for example, the line spacing) is detected. It is preferable to perform grouping based on the distance. For example, when three or more character areas are grouped together, the three or more character areas have the same character attribute, and the line spacing between the character areas is the same. It is preferable to group them into one group on the condition. Thereby, even if it has a same character attribute, the character area from which a line differs can be classified into another group. In addition, for example, when the distance between one character area and another character area is equal to or greater than a predetermined value, it is considered that the character strings do not constitute consecutive sentences. It is preferable. The predetermined value in this case can be set as appropriate.

  And the character block formation part 33 forms the rectangular character block used as the outline of all the character areas contained in the group for every group produced | generated as mentioned above. That is, the character block is formed corresponding to the group and is the smallest rectangular block that includes one or more character regions included in each group.

  When the character block forming process is performed by the character block forming unit 33 in this way, a plurality of character blocks 71 to 75 as shown in FIG. 6 are formed from the document image D1 shown in FIG. That is, the character areas 51 and 52 become character blocks 71, the character area 53 alone becomes a character block 72, the character areas 54, 55, 56, and 57 become character blocks 73, and the character areas 58, 59, and 60 become character blocks. The character area 61 becomes a character block 75 by itself. And each of such a some character block 71-75 becomes an expansion object area | region at the time of enlarging a character.

  The margin area extraction unit 34 extracts the margin area 43 from the document image D1 acquired by the document image acquisition unit 31, and sets the range of the maximum margin area that can be used for character expansion with respect to the extracted margin area 43. A processing unit to be set. The margin area extraction unit 34 first extracts a margin area 43 from a document image D1 including a character area 41, a non-character area 42, and a margin area 43 as shown in FIG. Next, the maximum blank area range that can be used for character enlargement is set for the extracted blank area 43. For example, the margin area extraction unit 34 determines a range excluding a margin area set by the document creation application program 19 in which the document image D1 is created (for example, a margin area arbitrarily set by the user for the document image D1). Set as the range of the maximum margin area that can be used when expanding characters. In the following, the range of the maximum blank area that can be used for character enlargement set as described above is referred to as an available blank area.

  FIG. 7 is a diagram showing an example of the available margin range 44 set in the document image D1 by the margin area extraction unit 34. As shown in FIG. A one-dot chain line shown in the figure is an outer frame of the usable margin range 44 and is a boundary line with a margin area defined in the document creation application program 19. And the area | region except the character blocks 71-75 and the non-character area | region 42 from the inside of the available margin area | region 44 becomes a margin area | region usable at the time of character expansion.

  As described above, the margin area extraction unit 34 can use the area excluding the margin area set at the peripheral edge of the document image D1 among all the margin areas 43 included in the document image D1 for character enlargement. The margin range 44 is set. As a result, it is possible to prevent a character enlarged in an enlargement process, which will be described later, from being greatly enlarged, for example, to a margin area at the peripheral edge of the document image D1 set by the user.

  The non-character region extraction unit 35 is a processing unit that extracts the non-character region 42 from the document image D1 acquired by the document image acquisition unit 31. As a specific method for extracting the non-character region 42 in the non-character region extraction unit 35, a known method may be employed. The non-character area extracting unit 35 extracts all the non-character areas 42 from the document image D1 including the character area 41, the non-character area 42, and the blank area 43.

  The enlarged frame setting unit 36 is a processing unit that sets individual enlarged frames for each of the plurality of character blocks 71 to 75 formed by the character block forming unit 33. For example, when setting an enlargement frame for one character block, the enlargement frame setting unit 36 sets an enlargement frame that includes the one character block and includes a blank area around the one character block. To do. At this time, the set enlargement frame is set as a substantially maximum rectangular frame that does not protrude outside the usable margin range 44 and does not interfere with other enlargement frames and the non-character area 42.

  FIG. 8 is a diagram illustrating an example of enlarged frames 81 a to 85 a set for the character blocks 71 to 75 by the enlarged frame setting unit 36. As shown in FIG. 8, an enlarged frame 81 a is set for the character block 71, and an enlarged frame 82 a is set for the character block 72. Similarly, an enlarged frame 83a is set for the character block 73, and an enlarged frame 84a is set for the character block 74. Further, an enlarged frame 85a is set in the character block 75. As described above, the enlarged frames 81a to 85a are set corresponding to the character blocks 71 to 75, respectively. The enlarged frames 81a to 85a are set so as not to overlap each other and not overlap the non-character area 42. Further, each of the enlarged frames 81a to 85a is set so as not to exceed the usable margin range 44 shown in FIG.

  Further, the enlargement frame setting unit 36 can enlarge the enlargement frames 81a to 85a set as described above to a range (printable range) that can be printed by the image forming apparatus 2. . Whether or not to enlarge the enlargement frames 81a to 85a to the printable range can be appropriately executed. For example, when the user instructs execution of enlargement processing of characters included in a document image, if the user specifies that the range of characters to be enlarged to the printable range by the image forming apparatus 2, the enlargement frame setting unit 36 After performing the process of setting the enlarged frames 81a to 85a as described above, the process of further enlarging the enlarged frames 81a to 85a to the printable range is performed.

  When enlarging the enlargement frames 81 a to 85 a to the printable range, the enlargement frame setting unit 36 detects the printable range of the image forming apparatus 2. Information regarding the printable range of the image forming apparatus 2 is preset in the printer driver 17. Therefore, the enlarged frame setting unit 36 detects the printable range of the image forming apparatus 2 by reading the information set in the printer driver 17. However, the present invention is not limited to this, and the printable range of the image forming apparatus 2 may be detected by other methods.

  FIG. 9 is a diagram illustrating an example of the printable range 46 detected by the enlarged frame setting unit 36. A two-dot chain line shown in the figure is an outer frame indicating the limit of the printable range 46, and the image forming apparatus 2 can perform image formation on the inner side. When such a printable range 46 is detected, the enlargement frame setting unit 36 performs a process of further extending the enlargement frames 81 a to 85 a set with the usable margin range 44 as a limit to the printable range 46. . Also at this time, the enlarged frame setting unit 36 does not cause the enlarged frames 81 a to 85 a to protrude outside the printable range 46 and does not interfere with other enlarged frames or the non-character area 42. Expand to become a frame.

  FIG. 10 is a diagram illustrating an example of the enlarged frames 81b to 85b in which the enlarged frames 81a to 85a are further expanded by the enlarged frame setting unit 36. When the enlargement frame expansion process is performed by the enlargement frame setting unit 36, as shown in FIG. 10, the enlargement frame 81a becomes the enlargement frame 81b, and the enlargement frame 82a becomes the enlargement frame 82b. The enlargement frame 83a becomes the enlargement frame 83b, and the enlargement frame 84a becomes the enlargement frame 84b. Further, the enlarged frame 85a becomes the enlarged frame 85b. These expanded enlarged frames 81b to 85b correspond to the character blocks 71 to 75, respectively. The enlarged frames 81b to 85b are expanded so as not to overlap each other and not overlap the non-character area 42. Further, each of the enlarged frames 81b to 85b is expanded so as not to exceed the printable range 46 shown in FIG.

  The enlargement processing unit 37 selects a character block to be enlarged from the character blocks 71 to 75 formed by the character block forming unit 33, and an enlarged frame set by the enlarged frame setting unit 36 for the selected character block. It is a processing part which expands so that it may be settled in the range. As described above, the enlargement processing unit 37 includes an enlargement determination unit 37a, an enlargement rate determination unit 37b, and an enlargement execution unit 37c. The enlargement determination unit 37a selects the character block to be enlarged, and the enlargement rate determination unit 37b determines the enlargement rate of the character block selected as the enlargement target. Then, the enlargement executing unit 37c performs a process of enlarging each character block based on the enlargement rate of the character block selected as the enlargement target. This will be described in more detail below.

  The enlargement determination unit 37a determines whether or not to enlarge the character block for each of the character blocks 71 to 75 formed by the character block formation unit 33, that is, whether or not the character block is to be enlarged. .

  The enlargement determination unit 37a first excludes, from the enlargement target, character blocks that are at the uppermost position or the lowermost position of the document image D1 and have a smaller block size than other character blocks. Such a character block corresponds to, for example, a header or footer included in the document image D1. This is because the header and footer represent the date and time of creation of the document, the creator, etc., and are less useful as information than the text of the document, etc. In this first exclusion condition, the character size may be evaluated instead of the block size. That is, a character block that is a character block at the uppermost position or the lowermost position of the document image D1 and that includes a character string having a smaller character size than other character blocks may be excluded from the enlargement target.

  Secondly, the enlargement determination unit 37a excludes a character block including the maximum character size among character sizes existing in the document image D1 from the enlargement target. The character block including the maximum character size in the document image D1 corresponds to, for example, a character block including a document title. A character string such as a document title often has a large character size that is already easier to read than other character strings when the document is created. In such a case, it is not necessary to perform enlargement processing. Therefore, in the present embodiment, the character block including the maximum character size in the document image D1 is excluded from the enlargement target. However, if the maximum character size in the document image D1 is smaller than the predetermined size, it may not be excluded from the enlargement target.

  As described above, the enlargement determination unit 37a specifies a character block to be excluded from the enlargement target from the character blocks 71 to 75 formed by the character block formation unit 33, and selects the remaining character block as the enlargement target. .

  FIG. 11 is a diagram illustrating the document image D1 after the enlargement determination process is performed by the enlargement determination unit 37a. In the illustrated example, the character block selected as the enlargement target by the enlargement determination unit 37a shows the corresponding enlargement frame, and the enlargement frame is omitted for the character block excluded from the enlargement target. That is, in the case of the illustrated example, the enlargement determination unit 37a excludes the character blocks 71, 72, and 75 from being enlarged. Then, two character blocks of the character blocks 73 and 74 are selected as enlargement targets.

  The enlargement rate determination unit 37b is a processing unit that determines the maximum enlargement rate for each character block selected as an enlargement target within a range that fits in the enlargement frame including the character block. For example, in the case of FIG. 11, the enlargement rate determination unit 37b determines the enlargement rate that is the maximum within the range where the character block 73 fits in the enlargement frame 83b, and the enlargement rate that becomes the maximum within the range where the character block 74 fits within the enlargement frame 84b. To decide. Here, when the enlargement ratio determination unit 37b determines the enlargement ratio of the character block, if the vertical magnification and the horizontal magnification are set to different values, the character string included in the character block extends in the vertical direction or the horizontal direction. It may be difficult to read characters. For this reason, it is preferable to determine the maximum enlargement ratio that fits in the enlargement frame while maintaining the same value for the vertical magnification and the horizontal magnification.

  For each character block selected as an enlargement target as described above, the maximum enlargement ratio that fits in the enlargement frame is determined. However, if each character block is enlarged at the maximum enlargement ratio that fits in the enlargement frame, the character size of the character string included in the character block becomes larger than the character size of the document title, and the title It may become inconspicuous. Therefore, the enlargement rate determining unit 37b determines the maximum enlargement rate that fits in the enlargement frame for each character block, and then performs processing for adjusting the enlargement rate. That is, the enlargement rate determination unit 37b performs character block enlargement processing based on the enlargement rate determined as described above, so that the character size of the character string included in the character block is the maximum in the document image D1. It is determined whether the character size is exceeded. If the maximum character size in the document image D1 is exceeded, the enlargement ratio of the character block is changed to the maximum value within a range not exceeding the maximum character size in the document image D1. If the maximum character size in the document image D1 is not exceeded, the enlargement ratio determined as described above for the character block is used as it is. By performing the enlargement ratio adjustment process in this manner, the enlargement ratio of each character block is finally determined.

  The enlargement execution unit 37c is a processing unit that enlarges each character block to be enlarged based on the enlargement rate of each character block determined by the enlargement rate determination unit 37b. When the enlargement execution unit 37c performs the character block enlargement process, the characters included in the character block are also enlarged. When enlarging a character block, the enlargement execution unit 37c performs an enlargement process so as not to exceed the enlargement frame set for the character block. For example, if the character block is enlarged based on the enlargement rate determined by the enlargement rate determining unit 37b and the enlarged character block protrudes from the enlargement frame, the character block is moved within the range of the enlargement frame. Also good.

  FIG. 12 is a diagram illustrating the document image D2 after the enlargement process is performed by the enlargement executing unit 37c. The character block 73 is enlarged to a size that substantially matches the enlarged frame 83b. Further, since the enlargement ratio of the character block 74 is adjusted so as not to exceed the maximum character size included in the document image D1, the character block 74 is not enlarged to a size that substantially matches the enlargement frame 84b, and is smaller than the enlargement frame 84b. It has become. Then, the character size of the character string included in the enlarged character block 74 is enlarged so as to be approximately the same size as the maximum character size in the document image D1.

  When the document image D2 in which characters are enlarged as described above is generated, the processing performed by the CPU 11 executing the character enlargement program 18 ends. The document image D <b> 2 is transmitted to the image forming apparatus 2 by the function of the printer driver 17. As a result, print output is performed in the image forming apparatus 2.

  Next, a specific processing procedure performed when the CPU 11 executes the character enlargement program 18 will be described. FIG. 13 is a flowchart illustrating an example of a detailed processing procedure of character enlargement processing for enlarging characters included in the document image D1. When the CPU 11 reads out the character enlargement program 18 and starts executing it, it first obtains a document image D1 to be processed (step S1). Then, the CPU 11 extracts the character area 41 included in the acquired document image D1 line by line (step S2). Then, by comparing each character area extracted in units of lines with other character areas located in the vicinity thereof, grouping is performed for each of one or more character areas having at least the same character attribute (step S3). ). Then, for each group, a rectangular character block that encloses the character area included in the group is formed (step S4).

  Next, the CPU 11 extracts a blank area 43 included in the acquired document image D1 (step S5). At this time, an available margin range 44 is set for the margin area 43 extracted from the document image D1. Then, the CPU 11 extracts the non-character area 42 included in the acquired document image D1 (step S6).

  Next, the CPU 11 sets an enlargement frame for each character block (step S7). The enlargement frame set at this time is set within the range of the usable margin range 44 and is set so as not to interfere with other enlargement frames and the non-character region 42. Then, it is determined whether or not the enlargement frame set in step S7 is expanded to the printable range 46 (step S8). When the enlargement frame is expanded to the printable range 46 (YES in step S8), it is set for each character block. The enlargement frame is extended to the printable range 46 (step S9). On the other hand, when the printable range 46 cannot be expanded (NO in step S8), the enlarged frame set in step S7 is directly used as the enlarged frame of each character block.

  Next, the CPU 11 determines whether or not to perform enlargement processing for each character block, and selects a character block to be enlarged (step S10). Then, an enlargement ratio is determined for each character block to be enlarged (step S11), and the character block is enlarged according to the enlargement ratio (step S12). At this time, the enlargement process is performed so as to fit inside the enlargement frame set for each character block. Then, the CPU 11 outputs a document image D2 obtained by enlarging the selected character block (step S13), and ends all the processes.

  As described above, in this embodiment, the computer 1 functions as an image processing apparatus that performs character enlargement processing. The image processing apparatus extracts a character area in units of lines from a document image having a character area and a margin area, and compares each character area extracted in units of lines with other character areas located in the vicinity thereof. Thus, at least one character area having the same character attribute is grouped to form a rectangular character block including the character areas included in each group. The rectangular character block is subjected to the enlargement process, and the enlargement process is performed so as to be within the range of the enlargement frame set for each character block.

  Therefore, in the present embodiment, it is not necessary to calculate the exact position of each character string included in the document image in order to perform the enlargement process, and if the character block includes a plurality of lines of character strings, the plurality of character strings are included. Can be expanded at once. When enlarging a character block, the character area and non-character area need to be rearranged after the enlargement process because the character block is enlarged to fit within the range of the enlargement frame that does not overlap other character blocks or non-character areas. There is no. Therefore, the character enlargement process can be performed efficiently, and the processing time until a document image with enlarged characters can be obtained can be shortened compared to the conventional method.

  In the present embodiment, since the character area and the non-character area do not overlap after the enlargement process is performed, it is possible to generate a document image that allows easy reading of characters without destroying the layout of the original document image. Furthermore, when the character strings constituting one sentence are described over a plurality of lines, the character strings of the plurality of lines are included in the same character block, and are expanded at a constant expansion rate. A character string constituting a sentence does not have a different character size for each line. Therefore, the document image obtained by performing the enlargement process is easy to read and has a good appearance.

  In the present embodiment, when performing the enlargement process, a character block that is at the uppermost position or the lowermost position of the document image and has a smaller block size than other character blocks is excluded from the enlargement target. Yes. Therefore, enlargement processing is not performed for character strings that are less useful as information, such as headers and footers, and only necessary characters can be enlarged while maintaining the appearance of the document. Also, by excluding character strings that are less useful as information from the enlargement target, it is possible to reduce the number of character blocks that are actually subjected to enlargement processing, so it is possible to perform character enlargement processing more efficiently. become.

  In the present embodiment, when the enlargement process is performed, the character block including the maximum character size included in the document image is excluded from the enlargement target. Therefore, a character string such as a title included in the document is not enlarged, and the appearance of the document can be prevented from being destroyed. Also in this case, since the number of character blocks that are actually subjected to enlargement processing can be reduced, the character enlargement processing can be performed more efficiently.

  Furthermore, in this embodiment, in order to make it easy to read the character after the enlargement process, the enlargement ratio of each character block is determined to be as large as possible. However, the character size of the character included in the character block is not enlarged. If the maximum character size included in the document image is exceeded, the enlargement ratio of the character block is determined so as not to exceed the maximum character size included in the document image. Thereby, it is possible to prevent a character string such as a title included in the document from becoming less conspicuous than other character strings. Then, it is possible to enlarge only a necessary character string while maintaining a good appearance of the document.

(Modification)
As mentioned above, although several embodiment regarding this invention was described, this invention is not limited to the content mentioned above, A various modification is applicable.

  For example, in the above-described embodiment, the case where the character enlargement program 18 is incorporated in the printer driver 17 is illustrated, but the present invention is not limited to this. That is, the character enlargement program 18 that performs the above-described processing may be provided as a single application program.

  In the above-described embodiment, the case where the computer 1 functions as an image processing apparatus that performs character enlargement processing is illustrated. However, the processing described above can be applied to other than the computer 1. For example, the image forming apparatus 2 may execute the character enlargement program 18 to perform the character enlargement process at the time of print output. When the image forming apparatus 2 is configured by an MFP, a document image can be input by reading a document using a scanner function. In such a case, it is possible to enlarge the characters included in the document characters by performing the above-described character enlargement processing on the document image input by the scanner function.

  In the above-described embodiment, when the usable margin range 44 is set, a range excluding the margin area set by the document creation application program 19 from the margin area 43 included in the document image is used. The case where it sets as 44 was illustrated. However, as described above, for example, a blank area set by the document creation application program 19 or the like does not exist in a document image obtained by reading a document with a scanner function. Therefore, in such a case, for example, a rectangular blank area inscribed in a character area and a non-character area included in the document image is virtually set, and the virtual blank area is set as the usable blank area 44. You may do it.

1 Computer (image processing device)
DESCRIPTION OF SYMBOLS 10 Control part 18 Character expansion program 31 Document image acquisition part 32 Character area extraction part (character area extraction means)
33 Character block forming part (character block forming means)
34. Margin area extraction unit (margin area extraction means)
35 Non-character area extraction unit 36 Enlarged frame setting unit (enlarged frame setting means)
37 Enlargement processing unit (enlargement processing means)
37a Enlargement determination unit (enlargement determination means)
37b Enlargement rate determining unit (enlargement rate determining means)
41 Character area 42 Non-character area 43 Margin area D1 Document image

Claims (9)

A character area extracting means for extracting a character area line by line from a document image having a character area and a margin area;
By comparing each character region in units of lines extracted by the character region extraction means with other character regions located in the vicinity thereof, grouping for each one or a plurality of character regions having at least the same character attribute, A character block forming means for forming a rectangular character block containing a character region included in the group;
Margin area extracting means for extracting a margin area of the document image;
For each character block formed by the character block forming means, an enlargement frame that includes the character block and includes a blank area around the character block is set, and each enlargement frame interferes with another enlargement frame. Enlargement frame setting means for setting so as to be substantially maximum in the range not to be,
An enlargement processing means for enlarging a character block included in each enlargement frame so as to be within the range of each enlargement frame;
An image processing apparatus comprising:   The image processing apparatus according to claim 1, wherein the character attribute is a font type or a character size.   The image processing apparatus according to claim 1, wherein the character block forming unit groups a plurality of character areas having the same character attribute and having the same line spacing into one group. . The enlargement processing means further includes an enlargement rate determining means for determining an enlargement rate of the character block when enlarging the character block,
The image processing apparatus according to claim 1, wherein the enlargement ratio determining unit determines a maximum enlargement ratio that falls within a range of the enlargement frame.   5. The enlargement ratio determining unit determines an enlargement ratio of a character block so that a character size included in the character block does not exceed a maximum character size existing in the document image. Image processing apparatus. The enlargement processing means further includes an enlargement determination means for determining whether or not to enlarge the character block.
The enlargement determination unit excludes a character block that is at the uppermost position or the lowermost position of the document image and has a block size smaller than that of other character blocks from the enlargement target. 6. The image processing apparatus according to any one of 5 above. The enlargement processing means further includes an enlargement determination means for determining whether or not to enlarge the character block.
The image processing apparatus according to claim 1, wherein the enlargement determination unit excludes a character block including a maximum character size among character sizes existing in the document image from an enlargement target. . Extracting a character area line by line from a document image having a character area and a margin area;
By comparing each character area extracted on a line-by-line basis with other character areas located in the vicinity, the character areas are grouped into one or more character areas having at least the same character attributes, and are included in each group. Forming a rectangular character block containing
Extracting a margin area of the document image;
For each character block, an enlargement frame that includes the character block and includes a blank area around the character block is set, and each enlargement frame is substantially maximized within a range that does not interfere with other enlargement frames. Steps to set,
Enlarging a block of characters contained in each enlargement frame to fit within the range of each enlargement frame;
A character enlargement processing method characterized by comprising: Computer
A character area extraction means for extracting a character area line by line from a document image having a character area and a margin area;
By comparing each character region in units of lines extracted by the character region extraction means with other character regions located in the vicinity thereof, grouping for each one or a plurality of character regions having at least the same character attribute, A character block forming means for forming a rectangular character block containing a character area included in the group;
Margin area extracting means for extracting a margin area of the document image;
For each character block formed by the character block forming means, an enlargement frame that includes the character block and includes a blank area around the character block is set, and each enlargement frame interferes with another enlargement frame. Enlarging frame setting means for setting to be substantially maximum in the range not to be, and
An enlargement processing means for enlarging a character block included in each enlargement frame so as to be within the range of each enlargement frame;
Character enlargement program characterized by functioning as

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