JP3830385B2 - Image processing apparatus, image processing method, and storage medium storing image processing program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus such as an electronic copying machine or a scanner having a function of optically reading a document image and digitally processing the read image data, an image processing method, and a storage medium storing an image processing program. About.
[0002]
[Prior art]
With the recent digitization of information, image input devices such as electronic copying machines and scanners that read printed image information such as pictures and characters and convert them into digital information have become widespread. In particular, an apparatus of a type in which an original is placed on a glass platen and the scanner side automatically moves the reading portion to read is typical. However, in an electronic copying machine using this type of image input apparatus, the peripheral portion of the output image of the electronic copying machine often becomes unnecessarily black due to unnecessary information input from the peripheral portion of the input document. is there. Due to the formation of such an inevitable unnecessary image, the quality of the output image of the electronic copying machine is degraded.
In order to solve this problem, Japanese Patent Application Laid-Open No. 5-153363 proposes a method for removing peripheral noise of an input document. According to this, in the input document surrounded by margins (margins), unnecessary image formation that occurs in the peripheral area of the output image due to unnecessary information is automatically prevented without performing the erasing area designation operation. be able to. In the present invention, noise, which is unnecessary information of the input document, is determined by the presence or absence of a black belt-like region in the peripheral portion of the input document. Only information determined to be noise is removed.
[0003]
[Problems to be solved by the invention]
By the way, as shown in FIGS. 10A and 10B, when a document such as a double-page book is read one page at a time using a scanner, there is a problem different from the above-described problem at the periphery of the document. Occurs. That is, depending on how the document is placed and the size of the document, the information on the adjacent page (the other page) enters the edge of the page to be originally input as shown in FIG. Here, the unnecessary information on the adjacent page that has entered is expressed as adjacent page entering noise.
However, this adjacent page entering noise exists in the peripheral portion of the input document, but is not determined as noise because it is not a black belt-like region. As a result, this adjacent page entering noise is output to the output image of the electronic copying machine.
[0004]
Accordingly, a first object of the present invention is to provide an image processing apparatus that automatically removes adjacent page entering noise.
A second object of the present invention is to provide an image processing apparatus in which the range for searching for adjacent page entering noise is variable in accordance with input image information.
A third object of the present invention is to provide an image processing apparatus in which a noise area of a spread portion is determined according to information on a connection area of black pixels.
A fourth object of the present invention is to provide an image processing apparatus in which the adjacent page entering noise area is determined from the positional relationship with the noise area of the spread portion.
A fifth object of the present invention is to provide an image processing apparatus capable of switching the strength level of noise area removal by preparing a plurality of parameters to be used.
A sixth object of the present invention is to provide an image processing method for automatically removing adjacent page entering noise.
A seventh object of the present invention is to provide a storage medium storing a computer-readable image processing program storing a program for realizing the functions of the above-described image processing apparatus.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, in an image processing apparatus having a function of digitally processing image data, data receiving means for receiving image data obtained by optically reading a document image as input data, and the data receiving means If the image data received by the method is image data of a spread document, a noise search range determining means for determining a range for searching for incoming noise on an adjacent page that is data of an adjacent page that enters the image data; Based on the range obtained by the noise search range determining means, the spread area noise area detecting means for detecting the noise area of the spread area, and the adjacent area based on the spread area noise area obtained by the spread area noise area detecting means. Adjacent page entering noise area detecting means for detecting an entering noise area of the page, the spread noise area detecting means and the adjacent page entering And noise removing means for removing a region obtained by write noise region detecting means as a noise region, by providing, to achieve the first object.
[0006]
According to a second aspect of the present invention, in the first aspect of the present invention, the search range of the incoming noise on the adjacent page determined by the noise search range determination unit is in the arrangement direction of the image data received by the data reception unit. The second object can be achieved by varying it accordingly.
According to a third aspect of the present invention, in the first aspect of the invention, the noise region of the spread portion detected by the spread portion noise region detecting means is determined according to data of a connected region of black pixels, thereby Achieve the purpose of 3.
[0007]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the incoming noise region of the adjacent page detected by the adjacent page incoming noise region detecting means is a spread portion detected by the spread portion noise region detecting means. The fourth object is achieved by determining the positional relationship with the noise region.
According to a fifth aspect of the present invention, in the first, second, third or fourth aspect of the present invention, the level of noise area removal by the noise removing means is selected from a plurality of parameters. The fifth object is achieved by being switchable.
[0008]
According to a sixth aspect of the present invention, there is provided an image processing method for digitally processing image data, the first step of receiving image data obtained by optically reading a document image as input data, and the first step. A second step of determining a search range for adjacent page incoming noise, which is adjacent page data entering the received image data, when the received image data is image data of a spread original; A third step for detecting a noise region of a spread portion that occurs when a document such as a spread book is read for the range obtained in the second step; and the spread obtained by the third step A fourth step of detecting an incoming noise region on an adjacent page based on a noise region of the part, and a region obtained by the third step and the fourth step A fifth step of removing a noise region, by including, to achieve the sixth object.
[0009]
According to the seventh aspect of the present invention, there is provided a storage medium storing an image processing program for digitally processing image data, wherein the image data obtained by optically reading a document image is received as input data; When the image data received by the first function is the image data of a spread document, the range for searching for the incoming noise of the adjacent page that is the data of the adjacent page that enters the received image data is determined. A third function for detecting a noise region of a spread portion that occurs when a document such as a spread book is read for the range obtained by the second function, and the third function A fourth function for detecting an intrusion noise area on an adjacent page based on a noise area of a spread part obtained by the function, and a region obtained by the third function and the fourth function as a noise area. By and storing a program for realizing the functions and the fifth removing, to achieve the seventh object of.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a block diagram illustrating the configuration of the image processing apparatus according to the present embodiment. The image processing apparatus includes an image device 1 such as a scanner, a central processing unit 2, a program storage ROM (read-only memory) or RAM (random access memory) 3, a display 4, a memory 5, a work area RAM ( Random access memory) 6 and a CD-ROM, FD (flexible disk) drive, etc. 7 are connected to each other via a bus 8.
[0011]
FIG. 2 is a flowchart showing the noise removal procedure for adjacent pages.
First, from the input image data input from the image device 1 such as a scanner, a range for searching for adjacent page entering noise is determined (step 10). As a method of determining the search range, a method of using a fixed value determined in advance, a fixed value determined in accordance with a document (image) size to be read in advance, and a value dynamically determined in accordance with image information described later. There is. However, as shown in FIG. 3, the entry of the adjacent page usually occurs only in the longitudinal direction of the document, so it is not necessary to set it at four places, top, bottom, left and right. At this point in time, it is unclear whether the next page has entered the left or right side, so it is necessary to set both sides.
[0012]
After the search range of the incoming noise on the adjacent page is determined, a black pixel connected region as shown in FIG. 5 is detected for the search range (step 11). The region obtained here becomes a candidate for spread noise and adjacent page entering noise. Extraction of a black pixel rectangle (run length) necessary for generating a spread noise region is performed in the direction shown in FIG. At this time, in addition to noise, some characters, ruled lines, photographs, and the like are included. Further, the spread noise candidates are narrowed down using the information of the spread noise area.
An adjacent page entering noise area is detected from the positional relationship with the spread noise area detected in step 11 (step 12).
Then, the finally determined spread noise area and adjacent page entering noise area are removed (step 13), and an image is output. However, if the spread noise area is simply removed, a necessary information area included (entered) in the spread noise area is deleted. Therefore, the spread noise region is removed at the run length level belonging to the spread noise region as shown in FIG. Therefore, it is necessary to manage the run length belonging to the spread noise region.
[0013]
Next, each step of the flowchart of FIG. 2 will be described in detail.
The method for determining the search range for the incoming noise in the adjacent page in step 10 of FIG. 2 varies depending on the image information (size, resolution, etc.) of the input document.
For example, as shown in FIG. 7, it is determined whether the input image is a portrait or a landscape. This is determined based on the width and height information of the input image. If the width of the input image is longer than the height direction, the landscape is determined. If the input image is longer than the width information, the portrait is determined. A range is set for only the longitudinal direction (two locations).
Further, the search range for adjacent page entering noise can be determined by the ratio of the width or height of the image. Therefore, even if the size of the document changes, it is possible to determine a search range corresponding to the original size.
[0014]
The spread noise region in step 11 in FIG. 2 is detected from information on the connection region of black pixels. The information of the black pixel connection area refers to, for example, the positional relationship between the spread noise area and the search range, and is a band-shaped information that exists from the upper end to the lower end or from the left end to the right end of the search range. Among the information of the connected area of black pixels, information existing near the upper end, lower end, left end, or right end of the image is determined as spread noise. By using information such as the size of the spread noise area (a certain size of spread noise is assumed to be spread) and the aspect ratio (the elongated area is assumed to be spread noise), the spread noise area candidates are narrowed down. Further, since the spread noise exists only on one side of both ends of the image, it finally exists only in one of the two set search ranges. No spread noise is found in both search ranges.
[0015]
The adjacent page entering noise region in step 12 of FIG. 2 is determined from the positional relationship with the noise region of the spread portion detected in step 11 of FIG. If noise at the spread portion is found, a rectangle positioned outside the noise simply becomes adjacent page entering noise. For example, when spread noise is detected in the right search range of the portrait image as shown in FIG. 8, a predetermined point (end point, start point) of the X coordinate when the X axis is taken in the horizontal direction of the spread noise area. , The middle point of the X coordinate is considered) and the rectangle located on the right side is determined to be adjacent page entering noise.
A mark (flag) is attached to the rectangle that is determined to be the incoming noise on the adjacent page. Then, at the stage of removing noise, the rectangular range is removed from the marked rectangle in the image, specifically, the white pixel is replaced.
[0016]
A plurality of parameters are prepared in order to enable the user to switch the noise removal strength level in step 13 of FIG. The parameters to be prepared include a parameter for searching for adjacent page noise and a parameter for detecting a spread noise area. The search range parameter of the adjacent page incoming noise indicates an instruction to narrow or widen the search range. In addition, the parameters for detecting the spread noise area include an instruction to reduce or increase the threshold of the rectangle size for judging as noise, and the distance from the edge of the image to be reduced or increased. There is something that shows instructions.
However, it is desirable that the parameters presented to the user side should be used together rather than presenting the above parameters as they are. For example, it is presented in the form as shown in FIG.
Since the noise removal step is a process that removes part of the image, the user can directly specify the parameters and switch the noise removal strength level to obtain the desired image. Is desirable.
[0017]
【The invention's effect】
According to the first aspect of the present invention, it is possible to remove the incoming noise of the adjacent page, which is an unnecessary image, and to prevent degradation of the quality of the output image.
According to the second aspect of the present invention, the method for determining the search range of the adjacent page entering noise can be changed according to the image information (size, resolution, etc.) of the input document.
According to the third aspect of the present invention, the spread noise region can be detected from the information of the connected region of black pixels.
[0018]
According to the fourth aspect of the present invention, the adjacent page entering noise region can be determined from the positional relationship with the noise region of the spread portion.
According to the fifth aspect of the present invention, the level of noise removal can be switched.
[0019]
According to the sixth aspect of the present invention, it is possible to remove adjacent page entering noise which is an unnecessary image.
[0020]
According to the seventh aspect of the present invention, it is possible to provide a program storage medium storing a program for realizing a function of removing adjacent page entering noise which is an unnecessary image.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus according to an embodiment.
FIG. 2 is a flowchart showing a procedure for removing incoming noise from adjacent pages.
FIG. 3 is a diagram showing a search range of adjacent page incoming noise.
FIG. 4 is a diagram illustrating a rectangular (run length) extraction direction;
FIG. 5 is a diagram illustrating a method of detecting a spread noise region.
FIG. 6 is a diagram illustrating a method of removing a spread noise region.
FIG. 7 is a diagram illustrating a method for determining an input image.
FIG. 8 is a diagram illustrating a right search range of a portrait image.
FIG. 9 is a diagram showing a presentation example of detection parameters for a spread noise region.
FIG. 10 is a diagram illustrating adjacent page entering noise.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image equipment, such as a scanner 2 Central processing unit 3 Program storage ROM (read-only memory) or RAM (random access memory)
4 Display 5 Memory 6 Work area RAM (Random Access Memory)
7 CD-ROM, FD (flexible disk) drive, etc. 8 buses

Claims (7)

In an image processing apparatus having a function of digitally processing image data,
Data receiving means for receiving, as input data, image data obtained by optically reading a document image;
When the image data received by the data receiving means is the image data of a spread document, a noise search range determination for determining a range for searching for incoming noise on the adjacent page, which is data of the adjacent page entering the image data Means,
For the range obtained from the noise search range determining means, the spread noise area detection means for detecting the noise area of the spread,
The adjacent page entering noise area detecting means for detecting the entering noise area of the adjacent page based on the noise area of the spread part obtained by the spread part noise area detecting means,
An image processing apparatus comprising: a spread noise region detecting unit; and a noise removing unit that removes a region obtained by the adjacent page entering noise region detecting unit as a noise region. 2. The image processing according to claim 1, wherein a search range for incoming noise determined by the noise search range determination unit is variable in accordance with an arrangement direction of image data received by the data reception unit. apparatus. The image processing apparatus according to claim 1, wherein the noise area of the spread part detected by the spread part noise area detection unit is determined according to data of a connection area of black pixels. The adjacent page entering noise area detected by the adjacent page entering noise area detecting means is determined from a positional relationship with the spread area noise area detected by the spread part noise area detecting means. The image processing apparatus according to 1. The image processing according to claim 1, 2, 3, or 4, wherein the level of noise area removal by the noise removing means can be switched according to selection from a plurality of parameters. apparatus. An image processing method for digitally processing image data,
A first step of receiving image data obtained by optically reading a document image as input data;
When the image data received in the first step is the image data of a spread document, the range for searching for the incoming noise of the adjacent page that is the data of the adjacent page that enters the received image data is determined. A second step;
A third step of detecting a noise region of a spread portion that occurs when a document such as a spread book is read for the range obtained from the second step;
A fourth step of detecting an intrusion noise region on the adjacent page based on the spread region noise region obtained by the third step;
An image processing method comprising the third step and a fifth step of removing the region obtained by the fourth step as a noise region. A storage medium storing an image processing program for digitally processing image data,
A first function for receiving, as input data, image data obtained by optically reading a document image;
When the image data received by the first function is the image data of a spread document, the range for searching for the incoming noise of the adjacent page that is the data of the adjacent page that enters the received image data is determined. The second function,
A third function for detecting a noise region of a spread portion that occurs when a document such as a spread book is read for the range obtained by the second function;
A fourth function for detecting an incoming noise area on an adjacent page based on a noise area of a spread portion obtained by the third function;
A memory storing a computer-readable image processing program storing a program for realizing the third function and a fifth function for removing the area obtained by the fourth function as a noise area Medium.

Images