JP2000013588A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decide an appropriate connection position even at the time of divided images obtained by reading a source image in which an original surface is rugged like a pasted mount or the like. SOLUTION: In an image extraction part 21, each time input for each line is present for the divided images A and B, image parts Ga and Gb of the overlap area of the divided images A and B are extracted. A block division part 22 divides the respective image parts Ga and Gb and generates two block images. A comparison part 23 compares the divided images A with B for the respective block images and generates two characteristic data. Then, connection candidate positions Z1 and Z2 are detected for the respective two characteristic data. In a connection position decision part 25, whether or not the original surface is rugged is decided based on the two connection candidate positions Z1 and Z2, and at the time of deciding the connection position for the pertinent line, the connection position eliminating the effects of ruggedness is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus for determining a connecting position when performing a connecting process on a plurality of divided images obtained by dividing an original image.

[0002]

2. Description of the Related Art In a device for reading an image such as an input scanner or the like, when the image to be read is large, it is not possible to read all the images by one reading. A connection process is performed on the plurality of images thus processed, and a whole original image is restored (reproduced).

For example, as shown in FIG. 13, a CCD line sensor 8 having a plurality of pixels arranged in an X direction which is a main scanning direction scans an original image 2 in a Y direction which is a sub scanning direction. Then, the first divided image is read, and then the CCD line sensor 8 is moved again in the X direction (the position indicated by the dashed line in FIG. 13), and is again scanned in the Y direction. Read. Thus, the entire original image 2 can be read. The connection processing is performed on the plurality of divided images obtained in this manner to generate image data for the entire original image 2. As shown in FIG. 13, the first
The overlapping area GR is read between the image and the second divided image.

FIG. 14 shows a schematic configuration of a conventional image processing apparatus that performs such a connection process. An image input unit 210 corresponding to an image reading head part such as an input scanner,
The image obtained by dividing one original image 2 is sequentially sent to the image processing unit 220. For example, FIG.
In the case where the original image 2 is read and input in a state where the original image 2 is split into two as shown in FIG.
The divided image to be input later is assumed to be B. Image input unit 210
Sends the divided images A and B to the image processing unit 220 sequentially. Note that the image input unit 210 outputs the divided images A and B
Are output each time the CCD line sensor 8 reads each line as described above.

[0005] The image processing section 220 outputs each of the divided images A and B to the subsequent connection processing section 240. Also,
The image processing unit 220 includes an image extraction unit 221, a comparison unit 222, and a connection position determination unit 225 inside.

The image extracting section 221 extracts, for each line, only the image portion Ga corresponding to the overlapping area GR from the divided images A previously inputted from the image input section 210, and compares this image portion Ga with the comparing section 222. Output to The extraction here is performed by, for example, extracting a predetermined number (k) of pixels in the −X direction from the end on the + X side of the divided image A.

The comparing section 222 temporarily stores an image portion Ga of the divided image A in a memory or the like (not shown) provided therein.

When the divided image B is input line by line later from the image input unit 210, the image extracting unit 22
1 extracts only the image part Gb corresponding to the overlapping area GR from the divided images B. The extraction here is, for example,
A predetermined number (j) in the + X direction from the end on the -X side of the divided image B
) Pixels. Then, the image portion Gb of the divided image B is sent to the comparing section 222.

The comparing section 222 reads the image portion Ga of the previously input divided image A from a memory or the like, and compares both image portions Ga and Gb. In this comparison, the portion to be compared of the image portion Gb of the divided image B is stepwise moved in the + X direction in pixel units, and the image portion Gb of the portion to be compared at each pixel position This is performed by comparing the image portion Ga read from the memory or the like.

Specifically, assuming that the movement amount for the image portion Gb is Z pixels,

[0011]

(Equation 1)

As shown in FIG. 2, characteristic data Sh (Z) for the movement amount Z can be obtained. In Equation 1, k represents the number of pixels included in the image portion Ga, and
i indicates the i-th pixel among the k pixels. That is, Equation 1 integrates the difference value for each pixel while shifting one of the divided images A and B for each pixel. The integrated value of the difference indicates the degree of correlation between the two images. Such characteristic data Sh (Z) is derived for each value of the movement amount Z (that is, each time one pixel is moved), and is set as a comparison result. FIG. 15 is a diagram illustrating a relationship between the movement amount Z obtained by Expression 1 and the characteristic data Sh (Z).

[0013] The comparison result in the comparing section 222 is sent to the joint position determining section 225.

In the connection position determining section 225, the comparing section 22
2 based on the comparison result sent from
The pixel position at which the degree of correlation between Gb and Gb is the highest is determined as the connection position. For example, when the characteristic data Sh (Z) as shown in FIG. 15 is obtained, the correlation between the image portions Ga and Gb becomes the highest when the movement amount Z minimizes the characteristic data Sh (Z). It will be. Joint position determination unit 22
The connection position determined in step 5 is sent to the connection processing unit 240 as connection position information.

The processing for determining the connection position in the image processing section 220 is performed in accordance with the input of the second divided image B.
Performed line by line.

The connection processing unit 240 stores the previously input divided image A provided from the image processing unit 220 in a storage unit such as a magnetic disk provided therein.
One image of the original image 2 is obtained by performing the connection processing of the divided images A and B based on the connection position information input from the connection position determination unit 225 in the image processing unit 220 together with the input of each line of the divided image B. Data can be generated. Then, the obtained one image data of the original image 2 is configured to be stored again in the storage unit or output to a subsequent device as an image.

The above-described processing is repeated also when a divided image of three or more divisions is input.

[0018]

By the way, when the splicing position is determined by the image processing apparatus as described above, when an original image having irregularities on the original surface such as a pasteboard is read, an appropriate image is read. The connection position cannot be determined.

For example, it is assumed that a document 2b is pasted on a document 2a as shown in FIG. The position of the CCD line sensor 8 when reading the divided image A is shown in FIG.
It is assumed that the position of the CCD line sensor 8 when reading the divided image B is 8b shown in FIG.

When the originals 2a and 2b are read at a predetermined magnification in such a case, the blackened portion P1 of the original 2a is projected onto the pixel Pa1 of the divided image A and the pixel Pb1 of the divided image B. Further, the blackened portion P2 of the original 2b is projected onto the pixel Pa2 of the divided image A and the pixel Pb2 of the divided image B.

The pixel positions 8a and 8b shown in FIG.
Are compared, the blackened portions P1 and P2 of the divided image A are
Are projected and the blackened portion P1,
It can be seen that the range in which P2 is projected is different.
In other words, the positions where the blackened portions P1 and P2 are projected cause a positional shift between the divided images A and B in the main scanning direction. This phenomenon is caused by the fact that the side of the step can be detected from one of the divided images, but the side of the step cannot be detected from the other divided image due to the presence of the uneven portion on the document surface. are doing.

By performing the above-described processing in the comparing section 222 based on the divided images A and B obtained as described above, the pixel Pa1 of the divided image A and the pixel Pb1 of the divided image B are obtained.
Is high when the amount of movement Z is the same as when the amount of movement Z is equal, and the degree of correlation is also high when the amount of movement Z is such that the pixel Pa2 of the divided image A matches the pixel Pb2 of the divided image B. . That is, the characteristic data Sh (Z) obtained in the comparing section 222 is as shown in FIG.
It can be said that the characteristic data Sh (Z) shown in FIG. 17 is obtained by synthesizing characteristic data having two different connection positions.

If the connection position is to be determined based on the characteristic data Sh (Z) as shown in FIG.
The connection position fluctuates between u and the connection position is not stable, and cannot be said to be an appropriate connection position.

As described above, if there are irregularities on the document surface in the image portions Ga and Gb in the overlapping area of the divided image A and the divided image B, the irregularities appear on the characteristic data Sh (Z), and an appropriate effect is obtained. The connection position cannot be determined, which is problematic.

The present invention has been made in view of the above-described problems, and is suitable for a divided image obtained by reading an original image having irregularities on a document surface such as a pasteboard. It is an object of the present invention to provide an image processing apparatus capable of determining a connection position.

[0026]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an image processing method comprising the steps of:
Image processing for determining, for each line, a connecting position for performing a connecting process between the first divided image and the second divided image in an overlapping region included in the divided image and the second divided image in an overlapping manner. An image input means for (a) sequentially inputting a first divided image and a second divided image to be connected to each other line by line, and (b) a first image processing unit for the line. By extracting an image of a predetermined portion from among the divided images, an image portion of an overlapping region of the first divided image is extracted, and an image of a predetermined portion is extracted from the second divided image of the line. Image extracting means for extracting an image portion of an overlapping area of the second divided image, and (c) the first image extracted by the image extracting unit.
(D) dividing a first image portion of the divided image and a second image portion of the second divided image at predetermined positions to generate a plurality of block images; A plurality of block images of the first image portion;
Comparing means for generating a plurality of characteristic data indicating a degree of correlation for each block image by comparing the plurality of block images of the second image portion; and (e) a first division for each of the plurality of characteristic data Connecting position detecting means for detecting a plurality of connecting candidate positions between the image and the second divided image; and (f) connecting position determining means for determining a connecting position for the line based on the plurality of connecting candidate positions. Have.

According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the block dividing means divides the first image portion into two at a central portion, thereby dividing the first image portion into two. By generating two block images and dividing the second image portion into two at the center portion, two block images are generated for the second image portion. If the detected connection candidate position is within a predetermined range, determine the connection position for the line from within the distribution range of the connection candidate position, and if the connection candidate position is not within the predetermined range, The connection position of the previous line is determined as the connection position of the line.

The invention described in claim 3 is the first or second invention.
In the image processing device described in the above, when the connection position determining means determines the connection position for the previous line as the connection position for the line, the connection position for a predetermined number of lines after the line is determined for the previous line. It is characterized by a connecting position.

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 comparing means includes a plurality of block images of the first image portion and a plurality of block images of the second image portion. When comparing with a plurality of block images, a predetermined weighting coefficient is accumulated for each pixel included in each block image.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <1. First Embodiment> FIG.
Is an image processing apparatus 100 according to the first embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG. As shown in FIG. 1, the image processing apparatus 100 includes an image input unit 10, an image processing unit 20, and a connection processing unit 40.

The image input unit 10 is a device that reads an original image and generates a plurality of divided images, such as an image reading head of an input scanner. In the following, the image input unit 10 outputs two divided images A and B for the original image.
Will be described. In this case, the image input unit 10 is configured to set X in the main scanning direction as shown in FIG.
The original image 2 is read by scanning the CCD line sensor 8 in which a plurality of pixels are arranged in the Y direction, which is the sub-scanning direction, to generate divided images A and B.

FIG. 2 is a diagram for explaining the divided images A and B. FIG. 2A shows an original image 2 and FIG.
Shows a divided image A, and FIG. 2C shows a divided image B. When the original image 2 as shown in FIG. 2A is divided and input, divided images A and B as shown in FIGS. 2B and 2C are obtained. The shaded areas shown in FIGS. 2B and 2C are the image parts Ga and Gb of the overlapping area obtained by overlapping the divided images A and B. Two divided images A and B
Are connected in this overlapping area.

In each of the two divided images A and B, as shown by the dashed line in FIGS. 2B and 2C, the mechanical structure of the image input unit 10 and the parts other than the original image 2 It is possible to predict the connection reference position in advance from the position of the pixel that has read the reference line provided in the. But,
Since the scanning reference position does not reflect the scanning unevenness, the bending of the document, and the unevenness of the document surface that occur when the actual original image 2 is read, the divided images A and B are connected at the respective connecting reference positions. When the processing is performed, image quality deterioration such as image distortion is caused.

Therefore, in this embodiment, the overlapping area of the divided image A to be inputted first is fixed at the connection reference position, and the overlapping area of the divided image B to be inputted later is divided into the divided image A.
In order to perform appropriate connection processing by moving by an appropriate amount of movement in the main scanning direction with respect to the overlapping area of
This determines an appropriate moving amount, that is, an appropriate connecting position.

The divided images A,
B is sent to the image processing unit 20. This image input unit 10
After that, first, the divided image A (first divided image) is sequentially output for each line in the main scanning direction (X direction), and after the entire divided image A is output, the divided image B (first divided image) is successively output. 2
Are output for each line in the main scanning direction.

The image processing unit 20 includes an image extracting unit 21, a block dividing unit 22, a comparing unit 23, and a connecting position detecting unit 24.
And a connection position determining unit 25 are provided.

The image extracting section 21 selects an image portion G of the overlapping area from among the divided images A and B obtained from the image input section 10.
a and Gb are extracted. The image extracting unit 21 first extracts the image portion Ga of the overlapping area of the divided image A and sends it to the block dividing unit 22 every time there is an input for each line of the divided image A.

FIG. 3 is a diagram for explaining the extraction of the image portion Ga of the overlapping area from the divided image A by the image extracting section 21. The image extraction unit 21 extracts k pixels to be compared from among the divided images A input for each line in the main scanning direction, and obtains an image portion Ga (k pixels) of the overlapping area. This extraction is performed line by line, for example, by extracting k pixels centered on the connection reference position (the position indicated by the dashed line in FIG. 3) for the divided image A.

When the image portion Ga of the overlap region extracted for one line of the divided image A is input, the block dividing section 22 divides the image portion Ga at a predetermined position and divides the image portion Ga into two block images Ga1 and Ga2. Generate For example, the block division unit 22 divides the image part Ga into a left part and a right part at a connection reference position that is the center of the image part Ga.
Then, the left part is set as the block image Ga1, and the right part is set as the block image Ga2. FIG. 4 is a diagram illustrating division of an image portion in the block division unit 22. FIG.
As shown in (a), the image portion G of the divided image A
a is divided into two blocks G
a1 and Ga2 are generated. 2 obtained in this way
The two block images Ga1 and Ga2 are sent to the comparison unit 23.

In the comparing section 23, the block images Ga1 and Ga2 of the image portion Ga of the overlapping area extracted for all the lines of the divided image A are temporarily stored in a memory or the like provided therein.

On the other hand, the entire image data of the divided image A input from the image input unit 10 is also guided to the subsequent connection processing unit 40 line by line, and the connection processing unit 40 is provided with a magnetic disk or the like provided therein. The data is sequentially stored for each main scanning line input to the storage unit. Accordingly, the storage section of the connection processing section 40 stores the entire image data of the divided image A shown in FIG.

When the image input unit 10 sends out the entire image data of the divided image A to the image processing unit 20, next,
The divided image B is transmitted to the image processing unit 20 line by line in the main scanning direction.

Each time the divided image B is input from the image input unit 10 line by line, the image extracting unit 21
Among them, only the image portion Gb corresponding to the overlapping area GR is extracted. The extraction here is performed, for example, with a predetermined number (j pieces) centered on the connection reference position of the divided image B or a connection position determined on the previous line of the line input from the image input unit 10. ) Is performed by extracting pixels. FIG. 5 is a diagram illustrating the extraction of the image portion Gb of the overlapping area from the divided image B by the image extracting unit 21. The one-dot chain line shown in FIG. 5 is the connection reference position or the connection position determined for the previous line. For example, with respect to the divided image B for the first one line, a predetermined number of pixels are extracted around the connection reference position,
For the divided image B of the second and subsequent lines, it is conceivable to extract a predetermined number of pixels around the joint position determined for the previous line. In this way, the image extracting unit 21 extracts j pixels to be compared from the divided image B input for each line in the main scanning direction,
An image portion Gb of the overlapping area is obtained.

The image portion Gb for each line of the divided image B extracted by the image extracting section 21 is sent to the block dividing section 22. That is, when the image extracting unit 21 receives the divided image B for one line from the image input unit 10, the image extracting unit 21 outputs the image part Gb for one line of the line to the block dividing unit 22.

When the image portion Gb of the overlap area extracted for one line of the divided image B is input, the block dividing section 22 divides the image portion Gb at a predetermined position and divides the image portion Gb into two block images Gb1 and Gb2. Generate For example, the block division unit 22 divides the image portion Gb into a left portion and a right portion at a connection reference position at the center of the image portion Gb or a connection position of the previous line. Then, the left part is set as the block image Gb1, and the right part is set as the block image Gb2. That is, as shown in FIG. 4B, the image portion Gb of the divided image B is divided into blocks, and two block images Gb1 and Gb2 are generated. The two block images Gb thus obtained
1 and Gb2 are sent to the comparison unit 23.

Then, the comparing section 23 outputs the block dividing section 2
When the block images Gb1 and Gb2 are input every 2 lines, the block images Ga1 and Ga2 of the divided image A corresponding to the line are read out from a memory or the like, and the block images Ga1 and B of the divided image A are read. The comparison with the image Gb1 and the comparison between the block image Ga2 for the divided image A and the block image Gb2 for the divided image B are performed. That is, a comparison is made between the left and right portions of the image portions Ga and Gb divided at a predetermined position.

Block image Gb1 and block image Ga1
Is compared to the block image Ga1 by shifting the block image Gb1 to the right and left in the main scanning direction (± X direction).
, And the block image Gb1 is compared at each pixel position with the block image Ga1 read from the memory or the like.

For example, image portions Ga and Gb corresponding to the same line in divided images A and B are respectively shown in FIG.
Suppose that it was obtained as shown in (a) and (b). In this case, assuming that the movement amount of the block image Gb1 is Z pixels, as shown in FIG. 6, the block image Gb1 of the divided image B is moved in pixel units, and the divided image A is compared with the block image Ga1. I do. In particular,

[0049]

(Equation 2)

Thus, the characteristic data Sh relating to the movement amount Z
Finding _L (Z) is performed. In Equation 2, n indicates the number of pixels included in the block image Ga1, and i indicates the i-th pixel among the n pixels. That is, Equation 2 is to integrate the difference value for each pixel while shifting the block image Gb1 in pixel units. The integrated value of the difference indicates the degree of correlation between the two images. Such characteristic data Sh _L (Z) is derived for each value of the movement amount Z (that is, each time one pixel is moved), and is set as a comparison result. A block image G as shown in FIGS.
When a1 and Gb1 are satisfied, as shown in FIG.
At 1, the blackened pixel of the block image Ga1 and the blackened pixel of the block image Gb1 are located at the same position. At this time, the degree of correlation is the highest.

The comparison between the block image Gb2 and the block image Ga2 is the same as above. The comparison between the block image Gb2 and the block image Ga2 is performed by moving the block image Gb2 stepwise in pixel units in the main scanning direction rightward and leftward (± X directions) with respect to the block image Ga2. This is performed by comparing the block image Gb2 at the pixel position with the block image Ga2 read from the memory or the like.

For example, image portions Ga and Gb corresponding to the same line in divided images A and B are respectively shown in FIG.
Suppose that it was obtained as shown in (a) and (b). In this case, assuming that the movement amount of the block image Gb2 is Z pixels, as shown in FIG. 7, the block image Gb2 of the divided image B is moved in pixel units, and the block image G2 of the divided image A is compared with the block image Ga2. I do. In particular,

[0053]

(Equation 3)

Thus, the characteristic data Sh relating to the movement amount Z
Finding _R (Z) is performed. In Equation 3, n indicates the number of pixels included in the block image Ga2, and i indicates the i-th pixel among the n pixels. That is, Expression 3 integrates the difference value for each pixel while shifting the block image Gb2 in pixel units. The integrated value of the difference indicates the degree of correlation between the two images. Such characteristic data Sh _R (Z) is derived for each value of the movement amount Z (that is, each time one pixel is moved), and is set as a comparison result. A block image G as shown in FIGS.
a2 and Gb2, as shown in FIG.
In the case of 4, since the blackened pixel of the block image Ga2 and the blackened pixel of the block image Gb2 are located at the same position, the degree of correlation is the highest at this time.

In this way, the comparison section 23 compares the left and right portions of the image portions Ga and Gb divided at a predetermined position, and two characteristic data Sh _L obtained as a comparison result. (Z), Sh _R (Z)
Is sent to the joint position detection unit 24.

In the connection position detecting section 24, the divided images A,
The connection candidate positions Z1 and Z2 are detected from each of the two characteristic data Sh _L (Z) and Sh _R (Z) obtained for the left portion and the right portion of the overlapping region of B.

The two characteristic data Sh _L (Z) and Sh _R (Z) obtained from the comparing section 23 are as shown in FIG. The connection position detection unit 24 detects the minimum value of each of the characteristic data Sh _L (Z) and Sh _R (Z) that is recognized as having the highest degree of correlation, and moves amounts Z1 and Z2 indicating the minimum value. To get. The movement amount Z1 obtained in this manner is a connection candidate position Z1 detected for the left portion of the overlap region, and the movement amount Z2 is a connection candidate position Z2 detected for the right portion of the overlap region. Then, the connection candidate positions Z1 and Z2 for the left and right portions of the overlap area detected by the connection position detection unit 24 are sent to the connection position determination unit 25.

The joint position determining section 25 determines whether or not the two joint candidate positions Z1 and Z2 to be inputted are within a predetermined range, that is, whether or not they are located close to each other. Specifically, for a preset threshold D,

[0059]

(Equation 4)

It is determined whether the condition (1) is satisfied. When the connection candidate positions Z1 and Z2 satisfy the condition of Expression 4, it can be determined that the connection candidate positions Z1 and Z2 are close to each other. It is determined that no irregularities exist. Conversely, if the connection candidate positions Z1 and Z2 do not satisfy the condition of Equation 4, it can be determined that the connection candidate positions Z1 and Z2 are not located within a predetermined range. It is determined that surface irregularities exist.

If the connection position determination unit 25 determines that there is unevenness on the document surface, it determines the connection position determined for the previous line as the connection position Zp for that line.

On the other hand, if it is determined that there is no irregularity on the document surface, the connection position Zp for the line is determined from the distribution range of the connection candidate positions Z1 and Z2 obtained by the connection position detection unit 24. . Connection candidate position Z
The distribution range of 1, Z2 refers to the range between the candidate connection positions Z1 and Z2 shown in FIG. For example, an intermediate position between the connection candidate positions Z1 and Z2 is determined as the connection position Zp, or the connection candidate positions Z1 and Z2 shown in FIG.
Of the two characteristic data Sh _L (Z) and Sh _R (Z), the connection candidate position having the smaller value may be determined as the connection position Zp.

The connection position Zp determined by the connection position determination unit 25 is sent to the connection processing unit 40.

As described above, the processing for one line in the main scanning for the divided image B input by the image processing unit 20 is completed, and the same processing is performed for the lines input thereafter. Then, every time there is an input for each line of the divided image B, the image processing unit 20 sequentially sends the connection position Zp for the line to the connection processing unit 40.

Further, the entire image data of the divided image B input from the image input unit 10 by the image processing unit 20 is guided to the subsequent connection processing unit 40 line by line.

The connection processing unit 40 reads out the image data of the divided image A from the storage unit provided therein, and stores the image data for each line of the divided image B input through the image processing unit 20 in the previous time. Is moved in the main scanning direction by the connection position Zp from the connection position of the line of No. 3 to perform the connection processing of the divided image A and the divided image B.

That is, the connection processing unit 40 stores the previously input divided image A given from the image processing unit 20 in a storage unit such as a magnetic disk provided therein, and stores the divided image A for each line of the divided image B. And the image processing unit 2
A connection position Z input from the connection position determination unit 25 within 0
One image data of the original image 2 is generated by performing a joining process of the divided images A and B based on p. And
One piece of image data of the obtained original image 2 is configured to be stored again in the storage unit or output to a subsequent device.

The above processing is repeated also when a divided image of three or more divisions is input.

As described above, in the image processing apparatus 100 of this embodiment, the image portion Ga of the divided image A is divided at a predetermined position to generate the left side block image Ga1 and the right side block image Ga2. At the same time, the image part Gb of the divided image B is also divided at a predetermined position to generate a left-side block image Gb1 and a right-side block image Gb2. Then, the right side block image Ga1 of the divided image A is compared with the right side block image Gb1 of the divided image B, and the connection candidate position Z for the left side is determined based on the comparison result.
1 as well as a connection candidate position Z2 for the right side portion is detected by the same method. Therefore, these connection candidate positions Z1, Z2
Is evaluated, it can be determined whether or not the document surface has irregularities. Then, connection candidate positions Z1, Z
2 is within the predetermined range, the connection position for the line is determined from the distribution range of the connection candidate positions, and if the connection candidate positions Z1 and Z2 are not within the predetermined range, the previous line is determined. Is determined as the connection position for the line, even if the divided image is obtained by reading an original image having irregularities on the original surface such as a pasteboard. The connection position does not change, and an appropriate connection position can be determined. As a result, the connection processing unit 4
0, the original image 2 restored becomes a high quality image.

It should be noted that, even if the original surface has irregularities, the connection position determination unit 25 may not be able to detect the irregularities on the original surface due to the influence of noise or the like. Therefore, when the connection position determination unit 25 determines the connection position of the previous line as the connection position of the line, the connection positions of a predetermined number of lines after the line are also connected to the previous line. It is good also as composition which determines as a position. With such a configuration, even when it is not possible to detect the unevenness existing on the document surface due to the influence of noise or the like, the influence of the noise or the like can be removed.

When the comparison unit 23 obtains the two characteristic data Sh _L (Z) and Sh _R (Z), the effective image components contained in each of the block images Ga 1 and Gb 1 and Ga 2 and Gb 2 are highly sensitive. A predetermined weighting coefficient K (i) may be integrated in order to reflect the characteristic data on the characteristic data.
That is, the two characteristic data Sh _L (Z) and Sh _R (Z) are

[0072]

(Equation 5)

[0073]

(Equation 6)

May be obtained by Here, the weighting coefficient K (i) is, for example, a coefficient set to have a maximum value at the center of each block image and become smaller toward the edge of each block image as shown in FIG. is there.
The characteristic data Sh is calculated using the weighting coefficient K (i).
_{When L} (Z) and Sh _R (Z) are obtained, the effective image components of each block image are amplified, so that it is possible to detect irregularities on the document surface with higher sensitivity. Note that the weighting coefficient K
(i) is not limited to the one shown in FIG.

<2. Second Preferred Embodiment> Next, a second preferred embodiment of the present invention will be described. In this embodiment, the image portions Ga and Gb of the overlapping area for the divided images A and B are divided into three or more block images. Then, characteristic data is generated for each of the plurality of block images. Then, a plurality of connection candidate positions are detected from the obtained plurality of characteristic data, and it is detected which of the plurality of block images includes an uneven portion on the document surface.

FIG. 10 is a block diagram showing a configuration of an image processing apparatus 100 according to the second embodiment of the present invention. As shown in FIG. 10, an image processing apparatus 10 according to this embodiment
0 has the same configuration as in the first embodiment. In the image processing unit 20 of this embodiment, the parts that perform processing different from those of the first embodiment are a block division unit 22, a comparison unit 23, a connection position detection unit 24, and a connection position determination unit 25.

In the block dividing section 22, 1 of the divided image A is
When the image portion Ga of the overlapping area extracted for the line is input, the image portion Ga is divided at a predetermined position to generate three or more block images Ga1, Ga2, Ga3,. For example, the block division unit 22
a into a plurality of block images Ga
1, Ga2, Ga3,... The plurality of block images Ga1, Ga2, Ga3,.
To the comparison unit 23.

In the comparing section 23, a plurality of block images Ga1, Ga2, Ga obtained for each line of the divided image A
Are temporarily stored in a memory or the like provided therein.

When the image portion Gb of the overlap area extracted for one line of the divided image B is input to the block dividing section 22, the image portion Gb is divided at a predetermined position as in the case of the divided image A. Then, three or more block images Gb1, Gb2, Gb3,... Are generated. And
A plurality of block images Ga1, Ga2, Ga3,...

Then, the comparing section 23 outputs the block dividing section 2
Block images Gb1, Gb2, G for every 2 to 1 line
When b3,... are input, the block images Ga1, Ga2, Ga3,.
b1, the block image Ga2 and the block image Gb2, the block image Ga3 and the block image Gb3,... are compared. That is, in the comparing unit 23, the image portion Gb
Each of the plurality of block images generated for
The corresponding block image of the image part Ga is compared.

The comparison here is the same as the comparison for each block image described in the first embodiment. Therefore,
The comparison unit 23 generates three or more pieces of characteristic data Sh1, Sh2, Sh3,... As a comparison result. For example,
When m block images have been generated for the image portions Ga and Gb, the comparison unit 23 generates m characteristic data. Then, the plurality of characteristic data is sent to the joint position detecting unit 24.

In the joint position detecting section 24, a plurality of pieces of characteristic data Sh1, Sh2, S
h3, ..., candidate connection positions Z1, Z2, Z
3, ... are detected.

The plurality of characteristic data Sh1, Sh2, Sh3,... Obtained from the comparing section 23 are as shown in FIG. FIG. 11A shows a case where there is no irregularity on the original surface, and FIG. 11B shows a case where there is irregularity on the original surface.

As shown in FIG. 11 (a), when there is no irregularity on the original surface, all of the plurality of characteristic data have the same movement amount Za.
Shows the minimum value near.

On the other hand, if the original surface has irregularities,
As shown in (b), a characteristic data group SG1 having a minimum value near the movement amount Zb, a characteristic data group SG2 having a minimum value near the movement amount Zc, and a characteristic data group SG3 having a substantially constant level. Can be distinguished.

Here, the reason why the characteristic data group SG3 having a substantially constant level appears will be described. As shown in FIG. 16, when the CCD line sensor 8 is at the pixel position 8a, the side surface of the step caused by the document 2b is not detected, but when the CCD line sensor 8 is at the pixel position 8b, the side surface of the step caused by the document 2b is detected. I do. For this reason, when a comparison is made by dividing the image into a plurality of block images as described above, a position having a high degree of correlation cannot be detected even if the block image on the step side surface is compared with the other block image. For this reason, when the original surface has irregularities, a characteristic data group SG3 having a substantially constant level appears.

The connection position detecting section 24 detects the movement amount indicating the minimum value for each characteristic data, and determines the connection candidate position Z
Are sent to the connection position determination unit 25 as 1, Z2, Z3,. Note that when the minimum value is detected for the characteristic data included in the characteristic data group SG3 of FIG.
In many cases, the minimum value is detected in a portion that is not close to any of b and Zc.

The joint position determining section 25 judges that the adjacent block image adjacent to the candidate joint position is on the same plane. For example, FIG.
If the characteristic data group SG1 of (b) is continuous characteristic data, the connection candidate positions are gathered in the vicinity of the movement amount Zb. Therefore, each block serving as a generation source of the characteristic data included in the characteristic data group SG1. The images are determined to be located on the same plane. Further, if the characteristic data group SG2 in FIG. 11B is also continuous characteristic data, since connection candidate positions are gathered near the movement amount Zc, the generation source of the characteristic data included in the characteristic data group SG2 is Each of the resulting block images is determined to be located on the same plane. In other words, the characteristic data groups SG1 and SG2 are determined to be planes at different height positions.

Then, the joint position determining section 25 calculates an average value of the joint candidate positions determined to be located on the same plane. FIG. 12 is a diagram illustrating connection candidate positions for each block corresponding to each block image when an average value of connection candidate positions determined to be located on the same plane is obtained. FIG.
As shown in (1), blocks 1 to α are regarded as the same plane, and are averaged connection candidate positions Zb. The blocks β to m are regarded as the same plane, and are averaged connection candidate positions Zc. Blocks (α + 1) to (β-1) indicate blocks that are not regarded as being on the same plane, and indicate characteristic data such as the characteristic data group SG3 in FIG. 11B. Therefore, in blocks (α + 1) to (β-1), one block image includes image information on the step side surface.

In such a case, the connection position determination unit 25
Outputs the boundary information Va and Vb about the uneven boundary portion to the subsequent connection processing section 40 as connection position information.

On the other hand, when there is no unevenness on the document surface, the plurality of characteristic data are as shown in FIG. 11A, and thus all the averaged connection candidate positions are Za. For this reason, the connection position determination unit 25 determines the movement amount Za as the connection position Zp, and outputs it to the subsequent connection processing unit 40.

As described above, the processing for one main scanning line for the divided image B input by the image processing unit 20 in this embodiment is completed, and the same processing is performed for the lines input thereafter. Is done. Then, every time there is an input for each line for the divided image B, the image processing unit 20 sets the boundary information V for that line.
a, Vb or the connection position Zp are sequentially transmitted to the connection processing unit 40.

Further, the entire image data of the divided image B input from the image input unit 10 by the image processing unit 20 is guided to the subsequent connection processing unit 40 line by line.

The connection processing section 40 reads out the image data of the divided image A from the storage section provided therein, and if the original has irregularities, the boundary information Va, V
Based on b, a connection process is performed at a position where the divided images A and B approach each other. For example, as shown in FIG. 12, when unevenness on the document surface is detected, the α-th block image Gaα of the divided image A is connected to the β-th block image Gbβ of the divided image B, thereby performing the joining process. I do.

If there is no irregularity on the document surface, a connection process is performed based on the connection position Zp. For example, the image data for each line of the divided image B input via the image processing unit 20 is moved in the main scanning direction from the previous line connection position by the connection position Zp, and the divided image A and the divided image A connection process with B is performed.

The above processing is repeated also when a divided image of three or more divisions is input.

As described above, in the image processing apparatus 100 of this embodiment, the image portion Ga of the divided image A is divided into three or more block images at a predetermined position, and comparison is performed for each block. To generate a plurality of characteristic data. Then, based on the plurality of characteristic data, it is detected whether or not the document surface has irregularities. If there is unevenness on the original surface, the connecting process of the divided images A and B is performed at a portion where the side surface of the step is not affected. Even in the case of a divided image obtained by reading a certain original image, the connecting position does not fluctuate, and even though the step side surface is detected in one of the divided images, the step difference is detected in the other divided image. It is possible to suppress the image quality deterioration that occurs at the time of the connection processing due to the fact that the side surface is not detected. As a result, the original image 2 restored by the connection processing unit 40 becomes a high-quality image.

When the comparison unit 23 obtains a plurality of characteristic data for each block image, the first embodiment is performed in order to reflect the effective image components contained in each block image with high sensitivity to the characteristic data. The predetermined weighting coefficient K (i) as described in the embodiment may be integrated. By obtaining the characteristic data using the weighting coefficient K (i), it is possible to amplify the effective image components of each block image, so that it is possible to detect irregularities on the document surface with higher sensitivity.

<3. Modification> In each of the above embodiments,
The connection processing when a plurality of divided images exist in the horizontal direction has been described as an example, but the present invention is not limited to this.
In other words, it is clear that even if a plurality of divided images exist in the vertical direction, an appropriate joint position can be derived by performing the same processing as described above for each line in the vertical direction.

Further, of the configurations shown in the above embodiments, the connection processing unit 40 may be configured as a separate unit.
That is, the image input unit 10 and the image processing unit 20 described in each embodiment can be configured to be incorporated in an input scanner or the like, and the connection processing unit 40 can be separately assigned to a computer or the like. Also in this case, the computer as the connection processing unit temporarily stores the divided image A on a magnetic disk or the like, and thereafter, the connection position Zp or the boundary information Va, Vb input together with the divided image B for each line.
May be configured to perform a linking process of connecting the divided image B of the line to the divided image A based on

In the above description, the image input unit 1
In the case of 0, the case where the divided images A and B are generated by reading the original image as in an input scanner or the like has been described, but the invention is not limited to this. For example, the image input unit 10 simply stores a plurality of divided images generated in advance, and sequentially transmits the plurality of divided images to the subsequent image processing unit 20 line by line in the main scanning direction. What can be transmitted may be sufficient. Even in such a case, the subsequent image processing unit 20 appropriately extracts the image,
Needless to say, processes such as comparison, connection position detection, and connection position determination can be performed.

Further, the connection processing of the divided images shown in this embodiment can be similarly applied to a case where the image processing unit 20 inputs three or more divided images from the image input unit 10. In this case, it is necessary to extract the overlapping area to be compared with the previously input divided image and also to extract the overlapping area to be compared with the later input divided image in accordance with the input of each divided image. . In this case, the divided image that is currently being input from the image input unit 10 is the second divided image, and the comparison unit 23 reads from the internal memory or the like is the first divided image.

[0103]

As described above, according to the first aspect of the invention, a plurality of block images obtained from the first image portion and a plurality of block images obtained from the second image portion are formed. By comparing, a plurality of characteristic data indicating the degree of correlation for each block image is generated, and a plurality of connection candidate positions between the first divided image and the second divided image are detected for each of the plurality of characteristic data, Based on these plurality of connection candidate positions, in order to determine the connection position for the line, even if the divided image is obtained by reading an original image such as a pasteboard or the like having irregularities on the original surface, Since the unevenness included in the divided image can be detected, an appropriate connection position can be determined. In addition, the influence of unevenness on the side surface of the step can be eliminated.

According to the second aspect of the present invention, the block dividing means generates two block images for the first image portion by dividing the first image portion into two at the central portion. By dividing the second image portion into two at the center portion, two block images are generated for the second image portion, and the connection position determining means determines that the connection candidate position detected for each block image is a predetermined position. If the connection position is within the range, the connection position for the line is determined from the distribution range of the connection candidate position, and if the connection candidate position is not within the predetermined range, the connection position for the previous line is set to the line. For the divided image obtained by reading the original image such as a pasteboard or the like having irregularities on the original surface, the connection position is determined. It never changes, it is possible to determine the appropriate splice point.

According to the third aspect of the present invention, when the connecting position determining means determines the connecting position for the previous line as the connecting position for the line, the connecting position determining means sets the connecting position for a predetermined number of lines after the line. Since the position is the connection position for the previous line, even if it is not possible to detect irregularities on the document surface due to the effects of noise, it is possible to remove the effects of noise etc. The connecting position can be set.

According to the fourth aspect of the present invention, when comparing the plurality of block images of the first image portion and the plurality of block images of the second image portion, each of the block images Is configured to accumulate a predetermined weighting coefficient for each pixel included in the image, so that an effective image component of each block image can be amplified, and the irregularities on the document surface can be detected with higher sensitivity. Becomes possible. As a result, a more appropriate connection position can be determined.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating divided images A and B.

FIG. 3 is a diagram illustrating extraction of an image portion Ga of an overlapping area from a divided image A by an image extracting unit.

FIG. 4 is a diagram illustrating division of an image portion in a block division unit according to the first embodiment.

FIG. 5 is a diagram illustrating extraction of an image portion Gb of an overlapping area from a divided image B by an image extracting unit.

FIG. 6 is a diagram illustrating comparison of block images in a comparison unit according to the first embodiment.

FIG. 7 is a diagram illustrating comparison of block images in a comparison unit according to the first embodiment.

FIG. 8 is a diagram illustrating two characteristic data obtained from a comparison unit according to the first embodiment.

FIG. 9 is a diagram illustrating an example of a weighting coefficient.

FIG. 10 is a block diagram illustrating a configuration of an image processing apparatus according to a second embodiment of the present invention.

FIG. 11 is a diagram illustrating a plurality of characteristic data obtained from a comparison unit according to the second embodiment.

FIG. 12 is a diagram showing connection candidate positions for each block corresponding to each block image.

FIG. 13 is an explanatory diagram of a case where an original image is read in a state of being divided into two parts.

FIG. 14 is a block diagram illustrating a schematic configuration of a conventional image processing apparatus.

FIG. 15 is a diagram illustrating a relationship between a movement amount Z and characteristic data Sh (Z).

FIG. 16 is a view for explaining reading of an original image such as a mounting sheet or the like in which the original surface has irregularities.

FIG. 17 is a diagram showing characteristic data when there is unevenness on a document surface, such as a pasteboard, obtained by a conventional image processing apparatus.

[Explanation of symbols]

 Reference Signs List 10 image input unit 20 image processing unit 21 image extraction unit 22 block division unit 23 comparison unit 24 connection position detection unit 25 connection position determination unit 40 connection processing unit A division image (first division image) B division image (second division image) Split image)

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Kunio Ren 304 No.1, Sayama Shinkaichi, Kumiyama-cho, Kuse-gun, Kyoto 1 F-term in the Kumiyama Office of Dainippon Screen Mfg. Co., Ltd. 5B057 AA11 CA16 CB16 CE09 CE10 CH09 DA07 DA08 DC34 5C076 AA12 AA19 AA36 BA08 CA10

Claims (4)

[Claims] 1. An overlapping area included in a first divided image and a second divided image obtained by dividing an original image,
An image processing apparatus that determines a connection position for performing a connection process between the first divided image and the second divided image for each line, and (a) the first processing unit that is a target of the connection process Image input means for sequentially inputting the divided image and the second divided image line by line, and (b) extracting an image of a predetermined portion from the first divided image for the line. By extracting an image portion of the overlapping region for the first divided image, and extracting an image of a predetermined portion from the second divided image for the line, the second divided image for the second divided image is extracted. Image extracting means for extracting an image portion of the overlapping area; (c) a first image portion of the first divided image extracted by the image extracting section, and a second image portion of the second divided image. Image part And (d) a plurality of block images of the first image portion, and a plurality of block images of the second image portion. Comparing means to generate a plurality of characteristic data indicating the degree of correlation for each block image; and (e) the first characteristic data for each of the plurality of characteristic data.
A connection position detecting means for detecting a plurality of connection candidate positions between the divided image and the second divided image; and (f) a connection position for determining a connection position for the line based on the plurality of connection candidate positions. An image processing apparatus comprising: a determination unit. 2. The image processing apparatus according to claim 1, wherein the block dividing unit divides the first image part into two parts at a center part, thereby obtaining two block images for the first image part. And by dividing the second image portion into two at the center,
Generating two block images with respect to the image portion of (a), the connection position determining means, when the connection candidate position detected for each block image is within a predetermined range, within the distribution range of the connection candidate position An image characterized in that a connection position for the line is determined from among the above, and if the connection candidate position is not within the predetermined range, a connection position for the previous line is determined as a connection position for the line. Processing equipment. 3. The image processing apparatus according to claim 1, wherein the connection position determining unit determines a connection position of a previous line as a connection position of the line, and determines a predetermined number of lines after the line. An image processing apparatus characterized in that a connection position for a line is set as a connection position for a previous line. 4. The image processing apparatus according to claim 1, wherein the comparing unit includes a plurality of block images of the first image portion and a plurality of block images of the second image portion. An image processing device for integrating a predetermined weighting coefficient for each pixel included in each block image when comparing