JP3358102B2 - Image composition method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image synthesizing method for synthesizing a plurality of images having overlapping areas.

[0002]

2. Description of the Related Art Conventionally, CCs have been used as image reading devices.
A two-dimensional imaging type scanner using a two-dimensional imaging element such as a D element is known (Japanese Patent Application Laid-Open No. 4-75537). This type of two-dimensional image capturing scanner includes an image capturing unit that captures an image of a document, a position sensor that detects an image capturing position, and the like.

[0003] An operator can place the two-dimensional image-capturing scanner on a document and capture an image within a predetermined image-capturing range at a time. For a document having a size exceeding the imaging range, imaging is performed a plurality of times while moving the imaging position as shown in FIG. The plurality of images captured in this manner are sequentially combined based on the imaging position of the position sensor, and are combined into one image.

When a rotary encoder used for a mouse or the like is used as the position sensor, a large detection error occurs due to factors such as unevenness of the document surface.
For this reason, there is a problem that the synthesized portion of the image information is significantly distorted. Therefore, the present inventor has considered an image combining method that corrects a combining position by paying attention to an overlapping portion between a plurality of images.

Hereinafter, the operation of this image synthesizing method will be described with reference to FIGS.
7 will be described. First, captured images are captured as image information A and B. Based on the image capturing positions of these pieces of image information, an overlapping area C in which images are captured in an overlapping manner.
Is calculated for each image information. Next, FIG.
As shown in (c), points of interest D1 and D2 are respectively defined inside these overlapping areas C, and circular partial images E1 and E2 around the points of interest D1 and D2 are selected.

[0006] As shown in FIG.
It is determined whether or not the transfer image coincides with the partial image E2 while transferring the image by a predetermined angle. Here, when the partial image E1 does not coincide with the partial image E2 even when rotated by 360 degrees, the target image D1 is shifted vertically and horizontally by a predetermined amount to reselect the partial image E1.
The above determination is repeated.

On the other hand, when the partial image E1 and the partial image E2 match, a translation vector S having the points of interest D1 and D2 as start and end points, respectively, and a rotation angle θ of the partial image E1 are obtained. By linearly mapping the image information A using the translation vector S and the rotation angle θ, the image information A
And the image information B can be converted to the same coordinates. Here, when the image information consists of a group of graphic data indicated by the vector information, image synthesis is performed by connecting both graphic data as they are.

When the image information is composed of bitmap information, the image information A is resampled in accordance with the sampling interval of the image information B, whereby the image synthesis is performed.

[0009]

By the way, in such an image synthesizing method, as the diameter of the partial images E1 and E2 is larger, the resolution of the rotation angle θ can be increased and the detection accuracy can be improved.

However, when the diameter of the partial images E1 and E2 is increased, the processing amount required to map the partial image E1 and the processing amount required to determine whether the partial images E1 and E2 match each other become: There has been a problem that it increases extremely in proportion to the square of the diameter. Invention according to claim 1, 2, intended to provide in order to solve such a problem, while reducing the amount of processing, the image synthesis method capable of determining the synthesis position of the image with high precision And

[0011] The present invention as described in claim 1, 2, and an object thereof is to provide an image synthesizing method that can search the rotation angle of the image more quickly. A third object of the present invention is to provide an image synthesizing system capable of searching for a translation vector and a rotation angle of an image with high accuracy and efficiency, in addition to the object of the second embodiment. .

According to a fourth aspect of the present invention, in addition to the object of the second aspect, there is provided an image synthesizing method capable of appropriately increasing the detection accuracy of the rotation angle in accordance with the size of the overlapping area of the images. The purpose is to do.

[0013]

FIG. 1 is a block diagram for explaining the first to fourth aspects of the present invention.

Hereinafter, the present invention will be described with reference to the reference numerals shown in FIG. The invention according to claim 1 is an area selecting means 1 for taking in a plurality of images and the positions of overlapping areas thereof, selecting all or a part of the overlapping area for each image to obtain a partial image, and A parallel search means 2 for comparing image information in a central region within the image and searching for a "parallel movement vector of the image" for matching the image information, and comparing the image information in a peripheral region in these partial images, Using the rotation search means 3 to search for the “rotation angle of the image” to be matched, and the above-described translation vector and rotation angle,
Bei and mapping means 4 for mapping a plurality of images on the same coordinates
The peripheral region is an arc-shaped region.
You.

According to a second aspect of the present invention, there is provided an area selecting means 1 for taking in a plurality of images and the positions of overlapping areas thereof and selecting all or a part of the overlapping area for each image to obtain a partial image. A parallel search means 2 for comparing image information in a central region in the partial images and searching for a “parallel movement vector of the image” for matching the image information, and comparing image information in peripheral regions in these partial images, A rotation search unit that searches for a “rotation angle of the image” that matches the image information; and a mapping unit that maps a plurality of images on the same coordinate using the translation vector and the rotation angle .
The peripheral area is an annular or arc-shaped area,
The region and the central region are provided apart from each other. According to a third aspect of the present invention, in the image synthesizing method according to the first or second aspect, the rotation search means 3 comprises:
The position of the central region where the image information matches is fetched from the parallel search means 2, and a region centered on the position is selected as the above-mentioned peripheral region.

[0016] The invention described in claim 4 provides the invention according to claims 1 to
In the image synthesizing method according to any one of the third to third aspects, the rotation search means 3 sets the diameter of the peripheral area larger as the overlapping area of the plurality of images becomes larger.

[0017]

In the image synthesizing method according to the first aspect, the area selecting means 1
Selects a partial image from the overlapping area of each image. The parallel search means 2 pays attention to the central region of these partial images,
The image information is compared to search for a “parallel movement vector of the image”.

The rotation search means 3 focuses on the peripheral area of these partial images, compares the image information, and searches for the "image rotation angle". The mapping means 4 maps each image on the same coordinates using the translation vector and the rotation angle thus obtained. Here, the above-described peripheral region is a region where the central portion is vacant, and therefore has a small area despite its large diameter. Therefore, by searching for a rotation angle using such a peripheral area, the resolution of the rotation angle is increased, and the amount of processing required for mapping and comparing the peripheral area is reduced.

Further, in the image synthesizing method according to the first aspect , an arc-shaped area is selected as the peripheral area. Image information located in such a peripheral region has the same distance from the center of the arc.

Therefore, when rotating the peripheral area, it is only necessary to shift a series of image information arranged in an arc shape, and the processing amount is reduced. Therefore, by making the peripheral region arc-shaped, it is possible to quickly and efficiently search for the “rotation angle of the image”. In addition, the surrounding area
With an arc-shaped area, even if several places on the circumference are missing
The diameter can be set to be larger than that of the annular region. That
Therefore, the effect that the detection accuracy of the rotation angle can be further improved is obtained.
is there. On the other hand, in the image synthesizing method according to the second aspect, the peripheral area
Is an annular or arcuate area, with the peripheral area and the center
Separate from the area. In this way, the translation vector is searched.
The central area for searching is the surrounding area for searching for the rotation angle.
It is provided separately from the area. Therefore, reduce the diameter of the central area.
Even if it does, the accuracy of rotation angle detection will not be impaired,
A central region of appropriate size to search for the line motion vector
Range can be set independently of rotation angle detection accuracy
Becomes In the image synthesizing method according to the third aspect, first, the parallel search means 2 searches for a translation vector. At this time, the image information in the central area is matched.

The rotation search means 3 fetches the position of the central area where the image information matches, and selects an area centered on the position as a peripheral area. Therefore, since the image information already matches at the center position of the peripheral region, the correlation of the image information between the peripheral regions is significantly increased. Therefore, the degree of coincidence of the peripheral regions is high, and it is possible to more accurately and efficiently search for the “image rotation angle”.

According to the image synthesizing method of the present invention, the rotation search means sets the diameter of the ring or the arc in the peripheral area to be large according to the size of the overlap area obtained by the area selection means. Therefore, when the overlapping area of a plurality of images is large, the diameter of the peripheral area is set large, and the resolution of the rotation angle can be appropriately increased.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an embodiment corresponding to claims 1 to 3. In FIG.
The scanner body 13 is placed on the scanner body 13, and an imaging unit 14 including a two-dimensional image sensor is arranged on the lower surface of the scanner body 13.

At both ends of the image pickup section 14, rotatable rollers 15 and 16 are arranged, and encoders 17 and 18 for measuring the rotation amounts of the rollers 15 and 16 on two axes are arranged respectively. The outputs of the imaging unit 14 and the encoders 17 and 18 are individually connected to an interface 19, and the interface 19 is connected to an interface 21 on an external board via a cable 20.

The output of the interface 21 is connected to a microprocessor section 22, and the monitor output of the microprocessor section 22 is connected to a screen 23. In addition, regarding the correspondence between the inventions described in the first to third aspects and the embodiment, the functions of the area selection unit 1, the parallel search unit 2, the rotation search unit 3, and the mapping unit 4 are described in the following. Corresponding to the function of.

FIG. 3 is a flowchart for explaining the operation of the embodiment. Hereinafter, the operation of the embodiment will be described with reference to these drawings. First, the operator places the scanner body 13 on the original 1
2 and an image of the document 12 is taken. The photoelectric output of the imaging unit 14 is taken into the microprocessor unit 22 via the interfaces 19 and 21 and stored as image information.

On the other hand, as the scanner body 13 moves,
The rollers 15, 16 arranged on the lower surface respectively rotate. These rotation amounts are measured by the encoders 17 and 18, respectively, and output to the microprocessor unit 22 as data indicating the imaging position. The imaging unit 14 captures the image information A and B as shown as an example in FIG. 4 by repeating the above operation.

The microprocessor section 22 calculates each overlapping area of the image information A and B based on the data of the imaging position (step S1). The microprocessor unit 22 selects, from each of the overlapping areas of the image information A and B, the points of interest D1 and D2 corresponding to the imaging locations. This point of interest D
Then, circular partial images E1 and E2 as shown in FIG. 4 are selected with the center at 1 and D2 (step S2).

These partial images E1 and E2 are composed of circular central regions F1 and F2 located at the central portion and annular peripheral regions G1 and G2 located at the inner peripheral portion. next,
As shown in FIG. 5, while rotating the image information located in one central area F1 by 360 degrees, the microprocessor section 22 matches the image information located in the other central area F2 within a predetermined allowable range. Is determined (step S
3).

Here, when the image information of the central areas F1 and F2 does not match (step S4), the position of the point of interest D1 is shifted by one pixel vertically and horizontally (step S5), and the central area F1 is selected again. Are repeated. On the other hand, when the image information of the central regions F1 and F2 match (step S4), a translation vector S having the current point of interest D1 as a start point and the point of interest D2 as an end point is obtained (step S6).

Next, the microprocessor section 22 sets the peripheral areas G1, G2 around the current points of interest D1, D2.
2 is selected (step S7). Here, the microprocessor unit 22 sequentially reads out the image information located in the peripheral areas G1 and G2 at equal intervals along the circumferential direction and accumulates the information on the memory. The microprocessor unit 22 determines whether or not the image information of the peripheral areas G1 and G2 matches within a predetermined allowable range on this memory (Step S).
8).

If the image information of the peripheral areas G1 and G2 do not match, the image information of the peripheral area G1 is rotationally shifted by one pixel on the memory (step S9), and the above determination is repeated. On the other hand, when the image information of the peripheral areas G1 and G2 match, based on the number of rotation shifts at the present time,
The rotation angle θ is obtained (step S10). Here, the microprocessor unit 22 translates the image information A by the translation vector S, and then, with the position of the point of interest D2 as a center,
The image information A is rotated by the rotation angle θ.

In this manner, the image information A and B are mapped on the same coordinates and are combined into one image. Therefore, in the image synthesizing method in the above-described embodiment, since the central portions of the peripheral regions G1 and G2 are vacant, the diameters of the peripheral regions G1 and G2 are maintained, while
The area becomes smaller. Therefore, it is possible to reduce the processing amount required for detecting the rotation angle according to the area while increasing the detection accuracy of the rotation angle according to the size of the diameter.

Further, since central regions F1 and F2 for searching for a translation vector are provided separately from peripheral regions G1 and G2 for searching for a rotation angle, central regions F1 and F2 are provided.
Even if F2 is reduced, the detection accuracy of the rotation angle is not impaired. Further, since the peripheral regions G1 and G2 are annular regions, when rotating the peripheral region G1, it is only necessary to shift a series of image information arranged in the circumferential direction, and the processing amount required for the rotationally transferred image is remarkably reduced. can do.

Since the peripheral areas G1 and G2 are selected after matching the image information of the central areas F1 and F2, the correlation of the image information between the peripheral areas G1 and G2 is significantly increased. Therefore, the “rotation angle of the image” can be more accurately and efficiently searched. In the above-described embodiment, an annular region having a predetermined diameter is selected as the peripheral regions G1 and G2 around the points of interest D1 and D2, but the configuration is not limited thereto.
As described in claim 4, the diameters of the peripheral regions G1 and G2 may be set larger as the overlapping area of the image becomes larger. With such a configuration, the detection accuracy of the rotation angle can be appropriately increased in accordance with the size of the overlapping area.

In the above-described embodiment, the peripheral area G
1, G2 is an annular area, but is not limited thereto, and may be any area located in the inner peripheral area of the partial images E1, E2. For example, if the peripheral region is an arc-shaped region, several places on the circumference may be missing, and the diameter can be set larger than that of the annular region. Therefore, there is an effect that the detection accuracy of the rotation angle can be further improved.

[0037]

As described above, according to the first aspect of the present invention, since the peripheral area is an arc-shaped area,
May be missing, and the diameter may be smaller than the annular area.
Can be set large. Therefore, the detection accuracy of the rotation angle can be improved.
It has the effect of being enhanced. Further, according to claim 2
In the present invention, since the central portion of the peripheral region is vacant, the peripheral portion has a small area despite its large diameter. Since the rotation angle is searched using such a peripheral area, it is possible to reduce the amount of processing required for detecting the rotation angle while improving the detection accuracy of the rotation angle according to the diameter.

Further, since the central area for searching for the translation vector is provided separately from the peripheral area for searching for the rotation angle, even if the central area is made smaller, the detection accuracy of the rotation angle may be impaired. Absent. Therefore, the size of the central region can be set independently. In particular, this
According to the inventions described in claims 1 and 2 , since the image information located in the annular or arc-shaped peripheral region has the same distance from the center, when rotating the peripheral region, a series of images arranged in the circumferential direction are used. It is only necessary to shift the image information, and the processing amount can be reduced. Therefore, it is possible to quickly search for the “rotation angle of the image”.

According to the third aspect of the present invention, since the image information already matches at the center position of the peripheral area,
The correlation of the image information between the peripheral areas is remarkably high. Therefore, the degree of coincidence of the images between the peripheral areas is high, and the “rotation angle of the image” can be more accurately and efficiently searched. According to the fourth aspect of the invention, when the overlapping area of the image is large, the diameter of the peripheral area is set to be large, so that the detection accuracy of the rotation angle can be appropriately increased.

As described above, in an image information processing apparatus or the like to which the image synthesizing method of the present invention is applied, the image synthesizing position can be obtained with high accuracy and speed. Can be speeded up.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating claims 1 to 4.

FIG. 2 is a diagram showing an embodiment corresponding to claims 1 to 3;

FIG. 3 is a flowchart illustrating the operation of the embodiment.

FIG. 4 is a diagram illustrating a partial image according to the embodiment.

FIG. 5 is a diagram illustrating a procedure for searching for a combined position in the embodiment.

FIG. 6 is a diagram illustrating a partial image in a conventional example.

FIG. 7 is a diagram illustrating a procedure for searching for a combined position in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Area selection means 2 Parallel search means 3 Rotation search means 4 Mapping means 12 Document 13 Scanner body 14 Imaging unit 15 Roller 17 Encoder 19, 21 Interface 20 Cable 22 Microprocessor unit 23 Screen

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G06T 3/00 400 G06T 3/00 300 G06T 1/00 280-340 H04N 1/387 JICST file (JOIS)

Claims (4)

(57) [Claims] 1. An area selecting means for taking in a plurality of images and a position of an overlapping area thereof and selecting all or a part of the overlapping area for each image to obtain a partial image, and an image in a central area in the partial image. Compare information,
"Image translation vector" to match the image information
A parallel search means for searching for, comparing image information in a peripheral region in the partial image,
A rotation search unit that searches for an “image rotation angle” that matches the image information; a translation vector searched by the parallel search unit; and a rotation angle searched by the rotation search unit. Mapping means for mapping the image of
Wherein the peripheral region, the image synthesis method, which is a circular arc-shaped region. 2. An area selecting means for taking in a plurality of images and the position of an overlapping area thereof and selecting a whole or a part of the overlapping area for each image to obtain a partial image, and an image in a central area in the partial image. Compare information,
"Image translation vector" to match the image information
A parallel search means for searching for, comparing image information in a peripheral region in the partial image,
A rotation search unit that searches for an “image rotation angle” that matches the image information; a translation vector searched by the parallel search unit; and a rotation angle searched by the rotation search unit. Mapping means for mapping the image of
The peripheral area is an annular or arcuate area,
The image combining method, wherein the peripheral area and the central area are provided apart from each other. 3. The image synthesis method according to claim 1 or claim 2, wherein the rotary searching section, from the parallel search means captures the position of the central area where the image information matches, about its position An image combining method, wherein a region obtained by the setting is the peripheral region. 4. The image synthesis method according to any one <br/> of claims 1 to 3, in accordance with the rotation searching section, overlap region of the plurality of images increases, the circumferential
An image synthesis method characterized by setting the diameter of a side region large.